Drought - November 2016

Issued 12 December 2016
Contents Of This Report:
Map showing Palmer Z Index
Percent Area of U.S. in Moderate to Extreme Drought, Jan 1996 to present
Georgia statewide precipitation, July-November, 1895-2016

Please note that the values presented in this report are based on preliminary data. They will change when the final data are processed, but will not be replaced on these pages.


National Drought Overview

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Detailed Drought Discussion


Overview


The U.S. Drought Monitor drought map valid November 1, 2016
The U.S. Drought Monitor drought map valid November 29, 2016.

During November 2016, numerous troughs and cutoff lows moving in the jet stream flow dragged cold fronts and low pressure systems across the CONUS. These weather systems brought precipitation to many parts of the country, but dominant ridging in the circulation pattern kept precipitation amounts below normal in most areas. Drought improved in parts of the West and Southern Plains where above-normal precipitation fell, but drought intensified and expanded across much of the South to Ohio and Mississippi Valleys, and parts of the Plains and Northeast, where precipitation was below normal. The dryness was especially severe in the moisture-starved Southeast, with many stations racking up long runs of consecutive dry days. A series of cold fronts and low pressure systems, which broke through the high pressure ridge in the Southeast beginning near the end of the month, brought much-needed precipitation (precipitation anomaly maps for weeks 1, 2, 3, 4, 5), but it was still not enough to make up for deficits that have built up over the course of November or since the beginning of the year. The persistent dry weather was coupled with abnormally high temperatures which enhanced evapotranspiration and exacerbated the drought conditions. When precipitation is integrated across the CONUS, November 2016 ranked as the 25th driest November in the 1895-2016 record. November was drier than normal over most of Alaska and Hawaii but wetter than normal over Puerto Rico. Drought and abnormal dryness expanded across Hawaii but disappeared from Puerto Rico. Drought expansion was greater than contraction, so the USDM-based national moderate-to-exceptional drought footprint increased across the CONUS from 26.8 percent at the end of October to 31.5 percent at the end of November (from 22.4 percent to 26.3 percent for all of the U.S.). According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 20.4 percent of the CONUS was in moderate to extreme drought at the end of November, an increase from last month's 14.4 percent.

Percent area of the CONUS in moderate to exceptional drought, January 4, 2000 to present, based on the U.S. Drought Monitor
Percent area of the CONUS in moderate to exceptional drought, January 4, 2000 to present, based on the U.S. Drought Monitor.


Palmer Drought Index


The Palmer drought indices measure the balance between moisture demand (evapotranspiration driven by temperature) and moisture supply (precipitation). The Palmer Z Index depicts moisture conditions for the current month, while the Palmer Hydrological Drought Index (PHDI) and Palmer Drought Severity Index (PDSI) depict the current month's cumulative moisture conditions integrated over the last several months. While both the PDSI and PHDI indices show long-term moisture conditions, the PDSI depicts meteorological drought while the PHDI depicts hydrological drought. The PDSI map shows less severe and extensive drought in parts of the West than the PHDI map because the meteorological conditions that produce drought and wet spell conditions are not as long-lasting as the hydrological impacts.

Palmer Z Index map Palmer Hydrological Drought Index map

Used together, the Palmer Z Index and PHDI maps show that short-term dry conditions occurred across a large part of the country including most of the East and South, much of the West, and parts of the Plains and Midwest. This short-term dryness expanded or intensified long-term dry conditions in November compared to October in the Mid-Atlantic, Midwest, Central High Plains, and Southeast, and reduced the intensity of long-term wet conditions in the Mid-Mississippi to Ohio Valleys, Southern Plains, and Pacific Northwest. Short-term wet conditions reduced long-term drought conditions in parts of the Southwest.



Standardized Precipitation Index


The Standardized Precipitation Index (SPI) measures moisture supply. The SPI maps here show the spatial extent of anomalously wet and dry areas at time scales ranging from 1 month to 24 months.

1-month Standardized Precipitation Index 2-month Standardized Precipitation Index 3-month Standardized Precipitation Index

6-month Standardized Precipitation Index

The SPI maps illustrate how moisture conditions have varied considerably through time and space over the last two years. Dryness dominates the Southeast for the last 1 to 9 months and partially at the 12-month time scale. There are even hints of dryness in the Southeast at 24 months. Dryness spreads from the Southeast into the Ohio Valley and Southern Plains at the 1 to 3 month time scales. Parts of the Northeast are dry at all time scales. Dry conditions are evident in the Central Plains to Central Rockies for the last 1 to 6 months. The Northwest to Northern Rockies are dry at the 1-month time scale, but wet at 2 to 12 months, with some dryness showing up in the Northern Rockies at 24 months. Dryness is apparent over parts of California at the 3- to 24-month time scales. Wet conditions dominate across the Plains to Great Lakes at 9 to 24 months, in the Northwest from 2 to 12 months, and along the immediate Mid-Atlantic coast from 2 to 24 months.


9-month Standardized Precipitation Index 12-month Standardized Precipitation Index 24-month Standardized Precipitation Index



Standardized Precipitation Evapotranspiration Index


The SPI measures water supply (precipitation), while the SPEI (Standardized Precipitation Evapotranspiration Index) measures the combination of water supply (precipitation) and water demand (evapotranspiration as computed from temperature). Warmer temperatures tend to increase evapotranspiration, which generally makes droughts more intense.

1-month SPEI for current month
1-month SPEI for current month.
1-month SPI for current month
1-month SPI for current month.

Temperatures were much warmer than normal across most of the CONUS during November, with record-breaking temperatures occurring in some states. The combination of these unusually warm temperatures and the lack of precipitation resulted in the 1-month SPEI map showing more severe drought conditions than the 1-month SPI map in many parts of the country. When the heat and dryness of the last two months is examined, the 2-month (October-November) SPEI map shows more severe drought conditions than the SPI map in the Southeast, Central Rockies to High Plains, and Southwest. This is also the case for the last three months (temperature anomaly, precipitation anomaly, SPI, and SPEI map) to six months (SPI vs. SPEI map).

Alabama statewide SPEI, September-November, 1895-2016
Alabama statewide SPEI, September-November, 1895-2016.
Tennessee statewide SPEI, September-November, 1895-2016
Tennessee statewide SPEI, September-November, 1895-2016.

The third warmest and third driest September-November, statewide, combined to give Alabama the most severe SPEI; the corresponding SPI tied as the most severe SPI in the 1895-2016 record. For Tennessee, the seventh driest and second warmest September-November gave the state the second worst SPEI on record.


36-month SPEI map 48-month SPEI map 60-month SPEI map

Significant differences between the SPEI and SPI maps begin to appear in the West at the 24-month time frame (SPEI vs. SPI) and become increasingly significant at the 36-month (SPEI vs. SPI), 48-month (SPEI vs. SPI), 60-month (SPEI vs. SPI), and even 72-month (SPEI vs. SPI) time scales. This is due to persistent above-normal temperatures in the West for the last several years which have increased evapotranspiration and exacerbated drought conditions. Eleven of the last 17 years (December-November periods) rank in the top 20 warmest category, with last year (December 2014-November 2015) being the warmest. Even with widespread near- to cooler-than-normal temperatures across the West in August, September, and October 2016, the December 2015-November 2016 12-month temperature still ranked as the third warmest on record.

Western U.S. precipitation, December-November, 1895-2016
Western U.S. precipitation, December-November, 1895-2016.
Western U.S. temperature, December-November, 1895-2016
Western U.S. temperature, December-November, 1895-2016.

This is especially the case in California, where the last three December-November 12-month periods were the three warmest such periods for the state in the 1895-2016 record. The last three years cap a period of persistent unusual warmth which has lasted over three decades. The precipitation for the last 12 months gave California a statewide precipitation rank of 35th wettest (87th driest) for December 2015-November 2016. But the persistent dryness since 2000 still gave the state the driest SPI for the last 60 months, seventh driest for the last 48 months, and tenth driest for the last 72 months. When the temperature is factored in, California has had the most severe SPEI on record for the last 60 and 72 months, and second most severe SPEI for the last 48 months.

California statewide temperature, December-November, 1895-2016
California statewide temperature, December-November, 1895-2016.
California statewide 60-month SPEI for November, 1895-2016
California statewide 60-month SPEI for November, 1895-2016.



Regional Discussion


NOAA NLDAS topsoil moisture percentiles for November 2016
NOAA NLDAS topsoil moisture percentiles for November 2016.
USGS streamflow percentiles for November 2016
USGS streamflow percentiles for November 2016.



CONUS Agricultural & Hydrological Impacts:

The dry and warmer-than-normal weather of November exacerbated drought conditions, especially in the Southeast and Central High Plains, while long-term drought continued in parts of the West. This is reflected in numerous agricultural, hydrological, and other meteorological indicators, both observed and modeled. The dry weather, with increased evapotranspiration, dried soils (USDA observations, SMOS satellite-based model, Leaky Bucket model, CPC model, NLDAS model topsoil and total column, VIC model, NASA GRACE surface and root zone soil moisture) and stressed vegetation (NOAA satellite-based VHI, stressed vegetation index, and drought risk index) (Crop Moisture Index [CMI] for weeks 1, 2, 3, 4, 5). Where the dry conditions have been continuing for several months, hydrological conditions such as streamflow and groundwater supplies (USGS observations, NASA GRACE estimates) were reduced, as well as reservoir levels in the West. On a national scale, as of November 29th, 32 percent of the nation's cattle inventory, 33 percent of the nation's hay, 27 percent of winter wheat production, 18 percent of soybean production, and 13 percent of corn production were in drought. These percentages are increases compared to the values for the end of October. According to November 27th U.S. Department of Agriculture (USDA) reports, ten percent of the winter wheat crop was rated in poor to very poor condition, which is an increase compared to the end of October. And 32 percent of the nation's topsoil moisture and 32 percent of the subsoil moisture were rated short to very short (dry to very dry), both also increases compared to last month. On a regional basis, conditions varied and were more extreme.

Drought conditions at the end of the month, as depicted on the November 29th USDM map, included the following CONUS core drought and abnormally dry areas:

  • Abnormally dry (D0) to moderate (D1) drought conditions covered a large part of the western U.S., with pockets of severe (D2) drought occurring in some areas, and extreme (D3) to exceptional (D4) drought lingering in California. —
    • Dry conditions or drought were evident in several indicators, including low soil moisture, groundwater, streamflow, and reservoirs; high evapotranspiration; some stressed vegetation; and low mountain snowpack. The month began with a few lingering large wildfires, and ended with most large wildfires extinguished or contained (wildfire maps for November 1, 5, 9, 15, 20, 27, 30). According to USDA statistics, topsoil moisture was short or very short (dry or very dry) in 50 percent or more of California (65%), Colorado (60%), Nevada (50%), New Mexico (67%), and Wyoming (50%); and subsoil moisture was short or very short in 50 percent or more of California (65%), Colorado (59%), Nevada (60%), and Wyoming (50%).
  • Abnormally dry and drought conditions expanded in parts of the Plains. —
    • Moderate to severe drought was evident in several pockets, including Kansas in the Central Plains, the Dakotas and adjacent Wyoming and Montana, in the north, and Texas and Oklahoma in the south. Dry soils, low groundwater, high evapotranspiration, and stressed vegetation were evident in some parts of the Plains. According to USDA statistics, 40 percent or more of the topsoil moisture was short or very short in Arkansas (47%), Kansas (45%), Nebraska (41%), Oklahoma (55%), and Texas (41%); 40 percent or more of the subsoil moisture was short or very short in Arkansas (64%), and Nebraska (42%).
  • Abnormally dry and drought conditions contracted in parts of the Northeast, while abnormally dry to extreme drought conditions expanded and intensified in other parts of the Northeast and Midwest. —
    • Indicators and impacts reflecting very dry conditions included parched soils, low or dried up ponds, and low groundwater and streamflow levels. According to USDA statistics, topsoil moisture was short or very short in 40 percent or more of Connecticut (85%),Kentucky (76%), Massachusetts (46%), New Hampshire (66%), Virginia (66%), and West Virginia (55%); subsoil moisture was short or very short in 40 percent or more of Connecticut (90%), Kentucky (75%), Maine (44%), Massachusetts (90%), New Hampshire (83%),Pennsylvania (47%), Rhode Island (80%), Virginia (50%), and West Virginia (50%).
  • Drought and abnormal dryness expanded and intensified in the Southeast to Lower Mississippi Valley, with exceptional drought expanding. —
    • Drought impacts were seen in low streamflows and groundwater levels, increased evapotranspiration, dried up ponds, and dry soils, with areas of stressed vegetation. The CMI showed agricultural drought at the beginning of the month, with conditions improving when the rains came at the end of the month. The number of large wildfires grew rapidly as the month progressed, then began to decrease when rain came at the end of the month. According to USDA statistics, topsoil moisture was short or very short in 40 percent or more of Alabama (100%), Florida (59%), Georgia (98%), Louisiana (74%), Mississippi (76%), North Carolina (43%), South Carolina (57%), and Tennessee (81%); subsoil moisture was short or very short in 40 percent or more of Alabama (100%), Florida (53%), Georgia (93%), Louisiana (70%), Mississippi (79%), South Carolina (49%), and Tennessee (80%).


Hawaii: November 2016 was mostly drier than normal across the Hawaiian Islands. The last 2 months were also drier than normal across most of the islands. But the last 3 months had a mixed precipitation anomaly pattern, and the last 5 to 6 to 8 months were generally wetter than normal. A mixed precipitation anomaly pattern is evident at the longer time scales (last 11, 12, 24, and 36 months). Moderate to extreme drought expanded to cover about eight percent of the state according to the November 29th USDM map. As noted by the National Weather Service in Honolulu, this was due to unseasonably persistent trade winds over the past couple of months. Pastures and vegetation are extremely dry. Even some of the trees are in poor shape or possibly dead.

Alaska gridded percent of average precipitation map for the current month
Alaska gridded percent of average precipitation map for the current month.

Alaska: A few stations along Alaska's north and south coasts and in the panhandle were wetter than normal, but most of the state was drier than normal during November 2016 (gridded maps and maps for climate divisions, low elevation stations, high elevation SNOTEL stations). The last two months were drier than normal statewide (low elevation stations, SNOTEL stations, SNOTEL basins). A mixed precipitation anomaly pattern was evident at the longer time scales (climate division maps for last 3, 6, 11, and 12 months) (gridded maps for last 3, 6, 11 months) (low elevation station maps for last 3, 5, 6, 8, 11, 12, 24, 36 months). November 2016 temperatures were warmer than normal except in the southwest, as seen on both the divisional and station maps. Warmer-than-normal temperatures dominate at the longer time scales (station maps for the last 2, 3, 11, 12 months) (climate division maps for last 3, 6, 11, 12 months) (gridded maps for last 3, 6, 11 months). In fact, the divisional maps show that it was record-warm virtually across the state for the last 11 to 12 months. The combination of unusual warmth and dryness resulted in below-average meltwater content in the mountain snowpack in most areas. About nine percent of the state continued abnormally dry on the November 29th USDM map.

Puerto Rico: Puerto Rico was wetter than normal during November. The wetter-than-normal pattern dominated the island at the 2- to 3-month time scales. Parts of the southeast were still drier than normal at longer time scales (last 6 to 11 months). Soils were moist across most of the island. The recent wetness was enough to eliminate drought and abnormal dryness from Puerto Rico, as seen on the November 29th USDM map.



CONUS State Precipitation Ranks:

Map showing November 2016 state precipitation ranks Florida statewide precipitation, November, 1895-2016

November 2016 was drier than normal across much of the CONUS from the Central Plains to the East Coast, and across much of the West. The dryness showed up on the statewide level, with 26 states in the CONUS ranking in their driest third of the 1895-2016 record. Five states had the tenth driest, or drier, November, including Florida (driest on record), Georgia (fifth driest), Maryland (sixth driest), Delaware (eighth driest), and South Carolina (ninth driest). Three other states were close — North Carolina and Pennsylvania (both twelfth driest) and Ohio (eleventh driest).

Map showing September-November 2016 state precipitation ranks Alabama statewide precipitation, September-November, 1895-2016

September-November 2016 was drier than normal across much of the Northeast, parts of the Southwest, and Central Rockies to adjoining Central Plains, and much drier than normal from the Southern Plains to Southern Appalachians. The dryness showed up on the statewide level with 16 states in the CONUS ranking in their driest third of the 1895-2016 record. Six states had the tenth driest, or drier, fall, with Alabama ranking third driest, Kentucky sixth driest, Tennessee seventh driest, Colorado eighth driest, and Louisiana and Mississippi ninth driest. Arkansas was close at eleventh driest.

Map showing June-November 2016 state precipitation ranks Georgia statewide precipitation, June-November, 1895-2016

The last six months were drier than normal across parts of the West and Great Plains and much of the Southeast and Northeast. Patches of wetter-than-normal conditions masked the state ranks in the West and Plains, except for Colorado, but dryness was more widespread in the eastern areas. In total, 13 states ranked in the driest third of the historical record for June-November, with four ranking in the top ten driest category. These included Georgia with the third driest June-November, Alabama (fifth driest), Connecticut (ninth driest), and Massachusetts (tenth driest).

Map showing January-November 2016 state precipitation ranks Georgia statewide precipitation, January-November, 1895-2016

January-November 2016 also was drier than normal across parts of the West and Plains, with dryness more widespread in the Southeast and Northeast. Thirteen states ranked in their driest third of the historical record. Three states were in the top ten driest category and included Georgia (sixth driest January-November), Connecticut (seventh driest), and Massachusetts (eighth driest). Alabama was close at twelfth driest.

Map showing December 2015-November 2016 state precipitation ranks Connecticut statewide precipitation, December-November, 1895-2016

A wet December in 2015 in the Southeast kept the southeastern states from having a top ten driest December-November, except Georgia still ranked 26th driest. Even with the wet December, parts of the Southeast were still drier than normal for the last 12 months, as were parts of the West and Northeast. Seven states ranked in their driest third of the historical record. Connecticut, again, ranked in the top ten driest category with the seventh driest December-November, rivalling the dryness of the 1960s drought of record. The last five December-November periods have been much drier than average in the state. Massachusetts was close, ranking twelfth driest.


Western U.S.


Percent Area of the Western U.S. in Moderate to Extreme Drought, January 1996-present, based on the Palmer Drought Index Percent Area of the Western U.S. in Moderate to Exceptional Drought, January 4, 2000-present, based on the U.S. Drought Monitor

Percent area of the Western U.S. in moderate to extreme drought, January 1900 to present, based on the Palmer Drought Index
Percent area of the Western U.S. in moderate to extreme drought, January 1900 to present, based on the Palmer Drought Index.

As noted earlier, November 2016 was drier than normal across much of the West, especially the Pacific Northwest and Northern Rockies. Parts of the Southwest were wetter than normal, especially New Mexico which had the 12th wettest November in the 1895-2016 record. The opposite precipitation anomaly pattern was evident for the water year to date (October 1, 2016-November 30, 2016) — the Northwest, Northern Rockies, and northern California were wetter than normal and the Southwest drier than normal. Several states in the West had a record or near-record warm November, and October-November 2016 ranked as the second warmest October-November when temperatures are integrated across the West. With temperatures warmer than normal across the West for November and the water year to date, precipitation that occurred fell more as rain than snow, resulting in a mountain snowpack that was well below normal in most areas. The slow melting during spring of a thick winter snowpack provides an important water source for the West during the summer dry season.

The above-normal precipitation which fell across parts of the West during November and the water year to date improved drought conditions slightly in a few areas, but it was not enough to erase deficits which have built up over the last several years. Consequently, the drought depiction in the West changed little on both the USDM and Palmer analyses. According to the USDM, 25.6 percent of the West was experiencing moderate to exceptional drought at the end of November, about the same as the previous month. The Palmer Drought Index percent area statistic for the West decreased slightly to 19.6 percent.


Northeast U.S.


Northeast region precipitation, January-November, 1895-2016 Percent Area of the Northeast U.S. in Moderate to Exceptional Drought, January 4, 2000-present, based on the U.S. Drought Monitor

Connecticut statewide Palmer Hydrological Drought Index, January 1900-November 2016
Connecticut statewide Palmer Hydrological Drought Index, January 1900-November 2016.

As noted above, several states in the Northeast CONUS have had very dry conditions recently. When the Northeast region as a whole is examined, November 2016 ranked as the 25th driest November in the 1895-2016 record; September-November 2016 ranked 41st driest; June-November ranked 29th driest; April-November, March-November, and January-November each ranked 19th driest; and December 2016-November 2016 ranked 30th driest. Record to near-record warm temperatures for the last 12 months have increased evapotranspiration and exacerbated drought conditions. According to the USDM, 54.4 percent of the Northeast was experiencing moderate to exceptional drought at the end of November, an increase from the 51.2 percent at the end of the previous month and the largest extent since 2002 in the 17-year USDM record.

Southern New England has been the epicenter of the Northeast drought. Based on the PHDI, Connecticut has been in drought continuously for the last three years, and the statewide PHDI has reached a magnitude second only to the 1960s drought of record.


Southeast U.S.


Southeast region precipitation, November, 1895-2016 Percent Area of the Southeast U.S. in Moderate to Exceptional Drought, January 4, 2000-present, based on the U.S. Drought Monitor

Georgia statewide Palmer Hydrological Drought Index, January 1900-November 2016
Georgia statewide Palmer Hydrological Drought Index, January 1900-November 2016.

As noted above, several states in the Southeast CONUS have had very dry conditions recently. When the Southeast region as a whole is examined, November 2016 ranked as the seventh driest November in the 1895-2016 record; October-November 2016 and July-November ranked 17th driest; June-November ranked 21st driest; March-November ranked 20th driest; and May-November, February-November, and January-November each ranked 33rd driest. Record to near-record warm temperatures for the last 12 months have increased evapotranspiration and exacerbated drought conditions. According to the USDM, 54.9 percent of the Southeast was experiencing moderate to exceptional drought at the end of November, a large increase from the 38.8 percent at the end of the previous month and the largest extent since 2012 in the 17-year USDM record.

The southern Appalachians to central Georgia and northeast Alabama have been the epicenter of the Southeast drought. Many locations in northern Georgia and northern Alabama had gone over two months without measurable rainfall. The Climate Extremes Index (CEI) days without rain component puts the occurrence of rain days (or lack thereof) into a 1910-2016 historical perspective. The lack of rain days in the Southeast during 2016 resulted in the ninth most extreme lack of rain days component for November and third most extreme lack of rain days component for September-November and June-November. These long runs of consecutive dry days were finally broken by a strong cold front which brought precipitation on the last couple days of November. Even with the end-of-November precipitation, some climate divisions in Alabama and Georgia still had the driest September-November and June-November, and even January-November, in the 1895-2016 record. Based on the PHDI, Georgia experienced a rapid intensification of the statewide PHDI during the last seven months, due largely to the second driest July-November on record.

Agricultural Belts


Primary Hard Red Winter Wheat Belt precipitation, October-November, 1895-2016
Primary Hard Red Winter Wheat Belt precipitation, October-November, 1895-2016.
Primary Hard Red Winter Wheat Belt temperature, October-November, 1895-2016
Primary Hard Red Winter Wheat Belt temperature, October-November, 1895-2016.

November 2016 was generally warmer than normal across the Primary Hard Red Winter Wheat agricultural belt, while parts were drier than normal and other parts wetter than normal. The month ranked as the 56th driest and second warmest November, regionwide, in the 1895-2016 record. October serves as the beginning of the growing season. October-November 2016 was generally drier and warmer than normal across the region, ranking as the warmest and 24th driest October-November, regionwide, on record.


NOAA Regional Climate Centers:


A more detailed drought discussion, provided by the NOAA Regional Climate Centers and others, can be found below.


As described by the High Plains Regional Climate Center, above-normal temperatures continued into November throughout the High Plains while the month was mostly dry across the region with a few pockets receiving above-normal precipitation. The wettest areas included the eastern and central Dakotas where precipitation exceeded 150 percent of normal. Otherwise, it was quite dry throughout the region, particularly in Kansas and parts of Colorado. A large part of Kansas received only 25 percent of normal precipitation, at best. It was the 10th driest November on record for Akron, Colorado. Pueblo, Colorado finally ended its streak of no measurable precipitation on the 17th. The streak lasted 63 days, which tied 1963 and 1934 for the 4th longest streak on record with no measurable precipitation in Pueblo (period of record 1888-2016). Colorado Springs, Colorado had its driest fall on record, and it was the 3rd driest in Dodge City, Kansas.

The continuation of above-normal temperatures resulted in several impacts around the region. Snowpack got off to a slow start in the Rockies; soil moisture was depleted across a large part of the region, especially in Colorado, Wyoming, Kansas, and Nebraska; the dryness increased the risk for rangeland fires in Wyoming; and winter wheat was challenged for growth. As of the end of November, most SNOTEL sites in Wyoming and Colorado were reporting a snow-water equivalent of approximately 50-75 percent of median. According to the U.S. Army Corps of Engineers, mountain snowpack water content was well below the 1981-2010 average going into December in the Missouri River Basin above Fort Peck and from Fort Peck to Garrison. To date, the mountain snowpack water content was at or below the levels of 2001, which is considered the lowest snowpack year during the last 20-year period. Snowpack was below normal in large part due to a warm fall, and precipitation fell mostly as rain instead of snow. Dryness also contributed to the issue, especially in Colorado. Despite the abysmal snowpack, it is early in the season and there is ample time for mountain snowpack recovery.

The continuation of dry conditions into November resulted in wide expansion of drought throughout parts of the High Plains region. Since late October, the area in drought (D1-D4) expanded from about 9 percent to 22 percent, and the area experiencing drought or abnormal dryness (D0-D4) increased from approximately 38 percent to 60 percent. Degradations in drought conditions occurred in all six states in the High Plains region. Colorado and Kansas saw the biggest expansion of drought during the past month. Nearly all (98 percent) of Colorado was experiencing at least abnormal dryness (D0), and 35 percent of the state was in moderate drought (D1) or severe drought (D2), most of which was occurring in the eastern half of the state. Meanwhile, the western half of Kansas has been particularly dry, and nearly 11 percent of the state was contending with D2 conditions. Eastern Colorado and western Kansas had a very dry fall, with much of the area receiving no more than 50 percent of normal precipitation.

As explained by the Southern Regional Climate Center, with the exception of west-central Texas, the Southern region experienced a third consecutive drier than normal month, and all six states in the region posted state-wide average monthly temperatures that were much warmer than normal, as was the case in October. Precipitation totals ranged from 50 to 70 percent of normal in Louisiana, Arkansas, Mississippi, and Tennessee. In Oklahoma, conditions were slightly drier, with many stations reporting less than half the expected precipitation, particularly in the north eastern quadrant of the state. In Texas, conditions were generally quite wet in the west central counties, with most stations reporting over twice the amount of normal precipitation.

Drought conditions deteriorated over the month of November. This is primarily due to the combination of the higher water demand produced by above normal temperatures, and a significant lack in precipitation. Though the amount of total drought coverage changed little over the past month, the severity of the drought areas changed significantly. Over the past month, the amount of areal coverage of extreme drought (D3) or worse has increased from 3.60 percent at the start of the month, to just over 13 percent near the end of the month. Extreme drought is currently observed in central Louisiana, central and eastern Tennessee, and over the majority of Mississippi. The state of Arkansas has also observed an increase in the amount of severe drought (D2) or worse.

In Texas, crops across the state were expected to be a mixed bag thanks to drought conditions increasing across the state during the month of October. According to state agronomist Mark Welch, only 86 percent of winter wheat was planted compared to the five year average of 88 percent and the percentage of poor and very poor rating increased by 5 percent. Some top cotton producers, however, were expected to turn out in good conditions after the forecast was poor thanks to timely rains. Thanksgiving dinner was expected to cost more this year. Some dairy products and poultry saw price reductions compared to last year while vegetables mostly saw price increases. (Information provided by the Texas Office of State Climatology).

As summarized by the Midwest Regional Climate Center, precipitation was mostly below normal in the Midwest in November and temperatures were warm, ranking as the second warmest November on record (1895-2016) for the Midwest as a whole. More than a thousand daily record high temperatures were set in November versus just a handful of record lows. Only Minnesota reported a statewide value wetter than normal for the month. Most of Missouri and Ohio received less than half of normal precipitation. Some parts of Missouri received less than a quarter of normal precipitation. A few pockets of slightly above normal precipitation were scattered from Wisconsin to Indiana but the only area with significantly above normal precipitation was in Minnesota. Fall precipitation was a mixed bag in the region with only Iowa, Minnesota, and Wisconsin above normal. The other six states, and the region as a whole, were below normal for the season. Kentucky was well below normal with only half its normal total for the season, ranking as the sixth driest fall on record for the state.

Drought in the southeastern US extended into Kentucky and conditions deteriorated in November. The month started out (November 1 USDM) with 8 percent of the region and 82 percent of Kentucky in moderate drought. By the end of the month (November 29 USDM), the coverage of moderate drought had expanded slightly to 11 percent of the region and 98 percent of Kentucky, severe drought (90 percent of Kentucky) and extreme drought (25 percent of Kentucky) expanded across large parts of the state. Significant forest fires burned in eastern Kentucky during the month.

As noted by the Southeast Regional Climate Center, precipitation was well below normal across the Southeast region during November, with numerous extremes recorded, and mean temperatures ranged from near average to above average. Monthly precipitation totals were less than 50 percent of normal across much of the region, with no precipitation observed in pockets of Florida and southeastern Georgia. At least 37 long-term stations, with one or more located in nearly every state, observed November precipitation totals that were ranked within the three lowest values on record. Fort Myers, FL (1892-2016) and Tarpon Springs, FL (1892-2016) tied their driest November on record, with no measurable precipitation recorded during the month. Brunswick, GA (1948-2016) observed its driest November on record, with only 0.04 inch (1.0 mm) of precipitation. Several locations tied their highest count of November days with no measurable precipitation, including Montgomery, AL (1872-2016; 28 days), Atlanta, GA (1878-2016; 28 days), Charleston, SC (1938-2016; 28 days), and Charlotte, NC (1878-2016; 27 days). Record-breaking streaks of no rainfall were observed at numerous locations across the western portion of the region. Eufaula Wildlife Refuge, AL (1967-2016), located about 75 miles southeast of Montgomery, recorded its longest streak of 91 days with no measurable precipitation, ending on the 28th of the month. This is also the longest streak for any station in Alabama's historical record. Tuscaloosa, AL (1948-2016) and Birmingham, AL recorded their longest streak of 71 and 61 days, respectively, with no measurable rainfall. In southwestern Georgia, Plains Experiment Station (1956-2016) and Montezuma (1904-2016) recorded their longest streak of 72 days with no measurable rainfall. Precipitation was well above normal across much of Puerto Rico and the U.S. Virgin Islands during the month. San Juan, PR (1898-2016) observed its wettest November and second wettest month on record, with 17.65 inches (448 mm) of precipitation.

Drought conditions intensified and expanded in coverage across the western half of the region during the month. In late November, a portion of every state in the region was classified in extreme (D3) drought for the first time since March 2008. Despite some beneficial rainfall from the 28th through the 30th, extreme-to-exceptional (D3-D4) drought covered approximately 97 percent of Alabama, 62 percent of Georgia, 21 percent of South Carolina, and 13 percent of North Carolina by the end of the month. Moderate-to-extreme (D1-D3) drought conditions developed across much of the Florida Panhandle, southwestern Virginia, and a portion of northern Virginia. A small area of moderate drought in southeastern Puerto Rico was eliminated during the month. Although the dry weather was favorable for harvesting activities, farmers in Georgia and Alabama struggled to dig up peanuts from excessively dry fields, and agricultural producers in the western Carolinas reported reduced yields of soybeans. Pastures and hay fields remained in very poor condition across drought-stricken portions of the region, which required livestock producers to sell off some cattle and continue feeding hay from diminishing reserves. In Alabama and Georgia, water for the cattle had to be hauled in by trailer, as ponds and streams continued to dry up. Cool season grains could not be planted for winter grazing in these areas because soil moisture levels were too low for seed germination. Across the interior portion of the region, the very dry forest floor coupled with seasonal leaf litter provided ideal conditions for an extraordinary number of wildfires, with over 180,000 acres burned during the month. About 28,000 acres of the Cohutta Wilderness in northern Georgia were burned by the Rough Ridge Fire, and thousands of North Carolina residents had to evacuate from several large fires, including the 7,142-acre Party Rock Fire near Lake Lure. The wind-driven transport of wildfire smoke caused poor air quality across a broad portion of the region, including the cities of Atlanta, GA, Asheville, NC, Charlotte, NC, and even cities farther away, such as Raleigh, NC and Charleston, SC. Respiratory issues were reported for both people and livestock in these affected areas. The extremely dry conditions caused large cracks to develop in many home foundations and roadways across northern Alabama.

As explained by the Northeast Regional Climate Center, November was a drier than normal month for the Northeast but, for the seventh month in a row, the Northeast averaged out to be warmer than normal. The region received 2.35 inches (59.69 mm) of precipitation, which was 61 percent of normal. All twelve states saw below-normal precipitation in November, ranging from 27 percent of normal in Delaware and Maryland to 83 percent of normal in Maine. Maryland had its sixth driest November since 1895, while Delaware had its eighth driest and Pennsylvania had its 12th driest. The Northeast wrapped up autumn on the dry side of normal, but it was the third warmest autumn on record for the Northeast with an average temperature of 52.8 degrees F (11.6 degrees C), 2.9 degrees F (1.6 degrees C) above normal.

The November 1 USDM, released on November 3, showed 51 percent of the Northeast was experiencing moderate, severe, or extreme drought, with another 17 percent of the region abnormally dry. Drought conditions generally remained unchanged or worsened in an area from central Maryland northeast through central Maine. Western and northern New York saw improving conditions. The November 29 USDM, released on December 1, indicated 54 percent of the Northeast was in a moderate, severe, or extreme drought, with another 24 percent being abnormally dry. In early November, Pennsylvania declared a Drought Warning for four counties (Monroe, Northampton, Carbon, and Lehigh), while thirty counties were in a Drought Watch and some counties returned to normal status. Western Massachusetts' drought level increased to a Drought Warning, while the Cape and Islands improved to a Drought Advisory. Western and central New York were reduced from a Drought Warning to a Drought Watch, which was also the drought status for the rest of the state. Streamflow during the month was generally near to below normal, with a few gauges having record to near record low streamflow. In early November, the New York Department of Environmental Conservation prohibited fishing along parts of Esopus Creek and Ashokan Reservoir because very low streamflow was stressing trout and additional stress could impact their ability to spawn. According to the Delaware River Basin Commission's website, low flows along the Delaware River in southern Pennsylvania and New Jersey allowed salt water to travel 19 miles upstream from its normal location for November, which resulted in the basin being placed in a Drought Watch on November 23. Groundwater and reservoir levels remained below normal in many of the drought-stricken areas. Worcester, Massachusetts's reservoir system was at 50.1% of capacity as of November 1, which was the lowest November 1 level since 1966. The city remained in a Stage 3 Drought Emergency. Data from the New Jersey Water Supply Authority showed that the Round Valley Reservoir fell to a new record low of 65.1% of capacity on November 28 and 29. As of November 30, the New York City reservoir system was at 56.3% of capacity compared to the normal 81.2%. Dry conditions also contributed to several wildfires in the region.

As summarized by the Western Regional Climate Center, November was drier than normal across much of the West, most notably in the intermountain region. Several storm systems impacted the West in November, though they were generally moisture-limited and did not produce significant precipitation totals beyond the coastal mountains. Areas of above-normal precipitation were observed along the Pacific Northwest coast, across Arizona and New Mexico, and in the Wyoming Rockies. In southern California, scattered coastal areas observed near normal precipitation, beneficial for the drought-stricken area.

A broad upper-level ridge dominated over the northern tier of the region this month, supporting drier than normal conditions over the Great Basin, Inland Northwest, and Montana. Along the Oregon-Nevada border, Denio reported only 0.03 in (0.8 mm), 3% of normal and the 3rd driest November since records began in 1951. Helena, Montana, observed only 0.02 in (0.5 mm) precipitation, 4% of normal and 2nd driest in a 79-year record. Small areas of Colorado and Montana saw expansion of drought conditions this month, mostly just denoting abnormally dry conditions. The ridge producing dry conditions over the northern interior West also favored above normal temperatures. Temperatures were above normal West-wide, with the greatest departures, in excess of 6 F (3.3 C) above normal, observed across the northern tier of the region.

Drought conditions in the western Great Basin were scaled back this month in the USDM. This was attributed mostly to October rains that reduced the long-term precipitation deficit and improved soil moisture and stream flow rather than November precipitation. Drought improvement was also noted in northern New Mexico and along the western Wyoming-Montana border.

November storms added to the emerging snowpack across western mountains, though totals were generally not substantial. The central Great Basin, northern Sierra Nevada, Cascades, and southern Utah were off to a good start with snow water equivalent (SWE) generally more than 75% of normal. Across the Rockies and southern Sierra Nevada, SWE is generally below 75% of normal, with much of the northern Rockies seeing less than 50% of normal. However, it was early in the season and small amounts of snow can make the difference between being well above and well below normal at this point.

In Alaska, the first two-thirds of the month were much warmer than normal across the majority of the state. The last third of the month saw the first consecutive days of below normal temperatures statewide in 2016; many interior locations saw temperatures below -30 F (-34.4 C). Average November temperatures in areas north of the Brooks Range were 5-10 F (3-6 C) above normal. From Fairbanks to Anchorage and down through southeast Alaska, temperatures were 2-4 F (1-2 C) above normal. The west-central region from Nome to Bethel was slightly cooler than normal. Precipitation was below normal in a large swath from Bethel to Anchorage north to the Brooks Range — including the entirety of the interior. Along the North Slope, Kuparuk reported 0.8 in (20 mm) precipitation, 533% of normal and its wettest November since records began in 1983. Precipitation in southeastern and southwestern Alaska was near normal. Further south, drier than normal conditions were observed throughout Hawaii, resulting in expansion of drought conditions on the leeward sides of all major islands. Lihue, Kauai, reported its driest November on record at 0.4 in (10 mm), 9% of normal. Records for Lihue began in 1950. Temperatures were variable across Hawaii, with some locations reporting above and some below normal. Molokai Airport recorded an average November temperature of 77.4 F (25.2 C), 2.6 F (1.4 C) above normal and the warmest since records began in 1949.

Pacific Islands: The NOAA National Weather Service (NWS) offices, the Pacific ENSO Applications Climate Center (PEAC), and partners provided reports on conditions across the Pacific Islands.

In the U.S. Affiliated Pacific Islands (USAPI) (maps — Federated States of Micronesia, Northern Mariana Islands, Marshall Islands, Republic of Palau, American Samoa, basinwide), November 2016 was drier than normal at Kapingamarangi, Kosrae, and Saipan, and slightly drier than normal at Chuuk.

Rainfall amounts were below the minimum thresholds (4 or 8 inches) required to meet most monthly water needs at Kapingamarangi, Kosrae, Nukuoro, Ulithi, and Woleai, all of which are stations in the Federated States of Micronesia (FSM). November rainfall was above the monthly minimum thresholds at the rest of the regular reporting stations in Micronesia. The monthly precipitation at Pago Pago was above their 8-inch minimum in November, breaking a string of 5 consecutive dry months. The 4- and 8-inch thresholds are important because, if monthly precipitation falls below the threshold, then water shortages or drought become a concern.

The last four months have been drier than the 8-inch threshold at Kapingamarangi. With only about 5000 gallons of water for the island, the Vice President and Governor of Pohnpei State issued emergency assistance for Kapingamarangi by deploying a ship to provide water and desalinators. Vegetation (taro patches) was turning brown during November and coconuts were drying out. The National Weather Service office on Guam issued a Drought Information Statement on November 21 for severe drought on Kapingamarangi. Conditions were dry across much of southern Pohnpei State, including Kapingamarangi and Nukuoro, as well as parts of Kosrae State.

As measured by percent of normal precipitation, Chuuk, Kapingamarangi, and Kosrae have been drier than normal in the short term (November and the last 3 months [September-November 2016]) as well as the long term (year to date [January-November 2016] and last 12 months [December 2015-November 2016]). Guam, Koror, Kwajalein, Lukonor, Majuro, Pohnpei, and Yap were wetter than normal in the short term but drier than normal in the long term. Pago Pago was wetter than normal for November, near normal at the 12-month time scale, and drier than normal at the other two time scales. Saipan was drier than normal for November but near to wetter than normal for the other three time periods.


X
  • Percent of Normal Precip
  • Precipitation
  • Normals
Pacific Island Percent of 1981-2010 Normal Median Precipitation
Station Name Dec
2015
Jan
2016
Feb
2016
Mar
2016
Apr
2016
May
2016
Jun
2016
Jul
2016
Aug
2016
Sep
2016
Oct
2016
Nov
2016
Dec-
Nov
Chuuk82%63%29%85%86%107%91%94%74%86%58%98%78%
Guam NAS74%65%120%79%52%53%125%67%141%124%115%137%90%
Kapingamarangi134%103%65%88%94%34%24%66%91%77%26%71%63%
Koror41%26%30%36%135%115%93%45%61%115%153%144%76%
Kosrae95%60%113%32%23%72%130%88%88%89%90%56%64%
Kwajalein59%64%17%45%21%57%142%101%83%64%168%126%89%
Lukonor56%123%61%51%113%102%73%43%73%120%74%198%77%
Majuro61%14%46%20%22%110%66%90%75%123%120%129%78%
Pago Pago183%34%54%101%329%102%73%81%83%83%55%127%97%
Pohnpei71%102%49%44%60%80%143%79%112%144%120%115%91%
Saipan154%54%105%106%68%87%57%42%186%191%48%79%107%
Yap58%35%34%15%62%113%54%67%88%66%164%156%78%
Pacific Island Precipitation (Inches)
Station Name Dec
2015
Jan
2016
Feb
2016
Mar
2016
Apr
2016
May
2016
Jun
2016
Jul
2016
Aug
2016
Sep
2016
Oct
2016
Nov
2016
Dec-
Nov
Chuuk9.256.402.097.0810.7312.1110.6111.279.5010.046.7310.39106.2
Guam NAS3.772.623.631.631.311.807.736.7720.8515.6513.1410.1389.03
Kapingamarangi13.209.406.0410.0212.784.073.309.337.387.612.146.5891.85
Koror4.592.642.532.689.9013.5516.258.288.2013.5118.0616.38116.57
Kosrae15.379.9514.565.153.9912.7018.9913.0712.4812.719.877.76136.6
Kwajalein3.902.020.461.051.133.809.819.968.126.9018.7314.1680.04
Lukonor6.3510.375.444.7512.8311.928.496.8410.3112.238.4118.02115.96
Majuro6.931.113.171.332.0511.127.2710.098.7813.7315.2817.3698.22
Pago Pago23.534.496.4910.7630.879.893.884.484.495.455.1212.86122.31
Pohnpei11.4113.494.645.7611.0116.0621.1812.1215.9118.1318.3917.00165.1
Saipan5.941.362.722.001.782.072.053.7624.4019.315.074.4274.88
Yap4.932.231.770.703.478.906.4610.0313.108.8920.0013.7894.26
Pacific Island 1981-2010 Normal Median Precipitation (Inches)
Station Name Dec
2015
Jan
2016
Feb
2016
Mar
2016
Apr
2016
May
2016
Jun
2016
Jul
2016
Aug
2016
Sep
2016
Oct
2016
Nov
2016
Dec-
Nov
Chuuk11.2510.107.258.3212.4711.3011.6611.9812.8611.7111.5110.61136.77
Guam NAS5.114.013.032.072.533.406.1810.1414.7412.6611.447.3899.09
Kapingamarangi9.849.159.2711.4313.6412.0813.7814.158.139.938.199.27145.85
Koror11.1610.188.567.447.3211.8317.4818.5313.5011.7711.8411.39152.90
Kosrae16.1116.6712.9316.0617.5117.7514.6414.9114.2214.2210.9413.83213.87
Kwajalein6.663.162.642.355.266.726.939.879.7410.7411.1811.2890.41
Lukonor11.278.418.939.2611.3111.6911.6515.9314.0410.1511.329.08151.36
Majuro11.397.746.886.589.4210.1111.0111.1711.6911.1712.7313.44125.25
Pago Pago12.8413.3412.0010.689.399.665.335.555.386.539.2610.14125.57
Pohnpei16.0813.189.5513.1718.4119.9614.8115.4314.2612.5515.2714.83182.36
Saipan3.852.532.591.892.632.383.628.9113.1310.0910.625.6170.25
Yap8.516.395.194.565.637.8512.0415.0814.8213.5012.188.83120.31

The current La Niña has brought dry weather to southern portions of Micronesia. But the end of the El Niño several months ago and subsequent ENSO-neutral conditions in the tropical Pacific has resulted in the return of much-needed rainfall to most of the USAPI region. Although the rains ended the drought that was occurring earlier this year, long-term precipitation deficits continued for some stations, as seen in the table below.

An analysis of historical data for the USAPI stations in the Global Historical Climatology Network-Daily (GHCN-D) dataset, augmented with fill-in data from the 1981-2010 Normals, indicated that, even though rains have returned to most stations during the last one to six months, several stations still had near-record dryness during December 2015-November 2016. The following table lists the precipitation ranks for November 2016, June-November 2016 (last 6 months), and December 2015-November 2016 (the last 12 months). Some stations have a long period of record and their dataset is fairly complete, while other stations have a shorter period of record and the dataset has some missing data. Stations with low ranks for the last 12 months (December 2015-November 2016) include: Kapingamarangi 3rd driest out of 14 years of data; Kosrae 3rd driest out of 29 years; Lukonor 4th driest (out of 20 years); Nukuoro 6th driest (31 years); Ulithi 4th driest (32); Woleai 4th driest (21); Yap 6th driest (65); Chuuk 4th driest (65); Koror 5th driest (65); Ailinglapalap 5th driest (30); Mili 7th driest (31); and Majuro 4th driest (62).

Rank, Number of Years with data, and Period of Record for USAPI stations for November 2016, June-November 2016, and December 2015-November 2016.
Rank of 1 = driest.
Station Nov 2016
Rank
Nov
No. of Years
Jun- Nov 2016
Rank
Jun- Nov
No. of Years
Dec 2015- Nov 2016
Rank
Dec- Nov
No. of Years
Period of Record
Jaluit 21 33 4 33 3 31 1981-2016
Koror 58 66 24 65 5 65 1951-2016
Woleai 10 33 11 24 4 21 1968-2016
Yap 59 66 19 65 6 65 1951-2016
Majuro 52 63 26 63 4 62 1954-2016
Mili 29 33 23 33 7 31 1981-2016
Ulithi 12 35 11 34 4 32 1981-2016
Ailinglapalap 30 33 19 32 5 30 1981-2016
Kosrae 5 49 7 36 3 29 1954-2016
Lukonor 31 33 4 20 4 20 1981-2016
Saipan 12 36 31 36 17 27 1981-2016
Pohnpei 42 66 47 65 13 65 1951-2016
Kwajalein 50 65 41 65 10 64 1952-2016
Kapingamarangi 10 28 2 15 3 14 1962-2016
Chuuk 30 66 2 65 4 65 1951-2016
Guam 39 60 39 60 17 59 1957-2016
Nukuoro 4 33 3 32 6 31 1981-2016
Pago Pago 32 51 9 51 27 50 1966-2016
Wotje 20 32 29 32 N/A 29 1981-2016
Utirik 11 15 5 5 2 2 1985-2016

Precipitation amount for current month for U.S. Affiliated Pacific Island stations

Percent of normal precipitation for current month for U.S. Affiliated Pacific Island stations

Percent of normal precipitation for last 3 months for U.S. Affiliated Pacific Island stations

Percent of normal precipitation for the year to date for U.S. Affiliated Pacific Island stations

Percent of normal precipitation for last 12 months for U.S. Affiliated Pacific Island stations

SPI values for seven time periods for Pacific Islands, computed by the Honolulu NWS office.
SPI values for seven time periods for Pacific Islands

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State/Regional/National Moisture Status
A detailed review of drought and moisture conditions is available for all contiguous U.S. states, the nine standard regions, and the nation (contiguous U.S.):

States
alabama arizona arkansas california colorado connecticut
delaware florida georgia idaho illinois indiana
iowa kansas kentucky louisiana maine maryland
massachusetts michigan minnesota mississippi missouri montana
nebraska nevada new hampshire new jersey new mexico new york
north carolina north dakota ohio oklahoma oregon pennsylvania
rhode island south carolina south dakota tennessee texas utah
vermont virginia washington west virginia wisconsin wyoming

Regional
northeast u. s. east north central u. s. central u. s.
southeast u. s. west north central u. s. south u. s.
southwest u. s. northwest u. s. west u. s.

National
Contiguous United States

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Contacts & Questions
For additional, or more localized, drought information, please visit:

Citing This Report

NOAA National Centers for Environmental Information, State of the Climate: Drought for November 2016, published online December 2016, retrieved on January 26, 2021 from https://www.ncdc.noaa.gov/sotc/drought/201611.

Metadata