National Climate Report - December 2016
- Climate Highlights — December
- The average contiguous U.S. temperature during December was 32.9°F, 0.2°F above the 20th century average. This was the 54th coolest December on record for the Lower 48. The average maximum (daytime) temperature was 42.5°F, 0.3°F below the 20th century average, the 46th lowest maximum value on record. The average minimum temperature was 23.2°F, 0.6°F above average. This was the 59th warmest value on record. All three values — Average, Maximum and Minimum Temperature — are categorized as "Near Normal" for the month.
- Temperature patterns were roughly evenly dividen between above normal, near normal, and below normal across the country. The south and east were generally warmer than normal. Florida had its fourth warmest December on record. The northwest quarter of the country was generally cooler than normal. Oregon had its 11th coolest December on record.
- Alaska had a near-normal statewide temperature during December. Its average temperature of 5.7°F; was 2.0°F above its long-term average, which dates to 1925. It was the 38th warmest December record, a month that shows considerable variability over the period of record.
- During December, record warm daily maximum and minimum temperature records outpaced record cold daily maximum and minimum temperature records by about a 3-to-2 ratio. There were 2,889 warm daily temperature records (1,608 maximum and 1,281 minimum) compared to 1,994 cold daily temperature records (924 maximum and 1,070 minimum).
- Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during December was 44.4, the 40th lowest value of the 122-year record, owing largely to warmer-than-normal temperatures in the more populated eastern half of the country.
- The December precipitation total for the contiguous U.S. was 2.69 inches, 0.34 inch above the 20th century average, ranking as the 34th wettest December on record, categorized as "Wetter than Normal". Nine of the last eleven Decembers have been wetter than the 20th century average.
- Above-average precipitation was observed across the majority of the country, particularly in the intermountain West, Northern Plains, and Upper Midwest . North Dakota saw its 3rd wettest December, and South Dakora its 4th wettest.
- According to the January 3rd U.S. Drought Monitor report, 22.5 percent of contiguous U.S. was in drought, down from 31.5 percent at the end of November. Drought conditions improved significantly across the mid-South and Southeast, with the exception of peninsular Florida. More modest improvements were observed in parts of the West.
**A comparison of the national temperature departure from average as calculated by NCDC's operational dataset (nClimDiv), the U.S. Historical Climatology Network (USHCN), and the U.S. Climate Reference Network (USCRN) is available on our National Temperature Index page.**
These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Climatic Data Center.
- Northeast Region: (Information provided by the Northeast Regional Climate Center)
- For more information, please go to the Northeast Regional Climate Center Home Page.
- Midwest Region: (Information provided by the Midwest Regional Climate Center)
- Temperatures for the month of December averaged within 2 degrees F (1 C) of normal across the entire Midwest. Despite the average for the month being near normal, some very cold and unseasonably warm temperatures both occurred in December. In the middle of the month, an Arctic blast dropped readings to less than -10 degrees F (-23 C) in eight Midwest states, sparing only Kentucky. Much colder readings were recorded in the northern states. Hundreds of daily record lows were set during the cold snap. Later in December, very warm conditions for the time of year brought temperatures above 70 degrees F (21 C) to parts of Missouri, Illinois, Indiana, Kentucky, and Ohio. In the warm spell, hundreds of daily record highs were set or tied in the Midwest.
- December precipitation was above normal in the northwestern and southeastern parts of the Midwest with drier than normal conditions stretching from Missouri to southern Michigan and northwestern Ohio. Large parts of Missouri and Illinois had monthly totals less than 50 percent of normal. In the northwestern third of the region precipitation totals ranged up to more than twice the normal amounts in northwestern Minnesota. Heavy rains in Kentucky, with totals topping 8 inches (203 mm) in the southeastern corner of the state, were slightly less than twice the normal amounts. Several hundred daily precipitation records were set in December, mostly in the middle of the month and in the last week of the year.
- Snow totals in December were above normal in the northern Midwest and below normal in the southern parts of the region. The largest snowfall amounts fell in northern Michigan near the Great Lakes where totals topped 30 inches (76 cm) for the month. December brought the first snow of the season to the central Midwest leaving just southeastern Missouri, extreme southern Illinois and Indiana, and much of western and central Kentucky without snow for the season.
- Drought eased in the Midwest during the month. December began with more than 10 percent of the region in drought, nearly 8 percent in severe drought or worse, and about 2 percent in extreme drought. The area in drought included nearly all of Kentucky and small parts of neighboring states. Rains in Kentucky led to the lessening of drought severity and eventually the complete elimination of drought in Kentucky by the end of the month. Two small areas in southern Missouri, just over 1 percent of the Midwest, had moderate drought as December came to and end.
- For further details on the weather and climate events in the Midwest, see the weekly and monthly reports at the Midwest Climate Watch page.
- Southeast Region: (Information provided by the Southeast Regional Climate Center)
- For more information, please go to the Southeast Regional Climate Center Home Page.
- High Plains Region: (Information provided by the High Plains Regional Climate Center )
- The warm pattern that had been present throughout much of the fall finally gave way to cooler conditions to begin the winter season. Arctic air masses pushed their way through the High Plains several times during December, contributing to monthly departures of up to 8.0 degrees F (4.4 degrees C) below normal in parts of the Dakotas and Wyoming. The greatest departures occurred mostly during the early and middle part of the month, punctuated by a bitterly cold outbreak of Arctic air on the 17th and 18th that brought the coldest temperatures of 2016 to some parts of the region. Temperatures in several locations dipped below -30.0 degrees F (-34.4 degrees C), which is in stark contrast to last year's mild winter season. Two locations had a top 5 coolest December on record: Rapid City, SD (3rd coolest) and Chadron, NE (4th coolest).
- The cooler temperatures were accompanied by wetter conditions throughout a large part of the region. Several storm systems brought rain, freezing rain, and snow to the High Plains, and the region experienced a wide range of weather events, including blizzards, ice storms, thunderstorms, and even tornadoes. One of the largest systems moved through on Christmas Day, creating hazardous travel conditions where wintry precipitation occurred and causing damaging thunderstorms on the warmer side of the system. These systems did have some positive impacts. For example, the moisture was beneficial to parts of the Dakotas where drought has been persistent, and improvements were made in these areas on the U.S. Drought Monitor by the end of the month. Also, ample snowfall occurred in the Rockies in Colorado and Wyoming, which helped the mountain snowpack recover after an abysmal start to the snowpack season. However, not all parts of the region received excess precipitation in December. It was much drier in Kansas and eastern Colorado, and some areas of these states experienced below-normal precipitation in December as well. As a result, drought conditions persisted in western Kansas and eastern Colorado, and abnormal dryness was introduced to eastern Kansas during December by the U.S. Drought Monitor.
- After a very warm fall, the pattern shifted in December to bring below-normal temperatures to most of the High Plains region. Departures of 6.0-8.0 degrees F (3.3-4.4 degrees C) below normal were common in the western Dakotas and northern Wyoming. While widespread record-breaking cold did not occur, a few top 10 records for coolest December were set: Rapid City, SD (3rd coolest); Chadron, NE (4th coolest); Casper, WY (7th coolest); and Sheridan, WY (9th coolest). Otherwise, temperatures across most of the High Plains were slightly below normal and not record-breaking. Only western Colorado experienced above-normal temperatures on the whole in December.
- Several outbreaks of Arctic air during the first half of December were to blame for the below-normal temperatures that occurred in much of the region. The most impressive outbreak came through on the 17th and 18th. Nearly the entire region set minimum temperatures for the month on one of these two days. In fact, many locations experienced their lowest temperature of the year, as last winter was rather warm across most of the High Plains. Quite a few daily record minimum temperatures were set on the 17th and 18th. Windy conditions accompanied the cold, producing dangerous wind chills as low as -50.0 degrees F (-45.6 degrees C). Some locations were quite warm just before this Arctic outbreak, producing large temperature swings. For example, in Pueblo, Colorado the temperature went from 69.0 degrees F (20.6 degrees C) on the 16th to -19.0 degrees F (-28.3 degrees C) on the 17th! Temperatures did rebound somewhat during the latter half of the month; in fact, parts of Nebraska, Kansas, and Colorado had high temperatures in the 60s and even 70s on Christmas Day! In Kansas, daily record highs were set on the 25th in Wichita, Topeka, and Concordia.
- Wet and dry conditions both prevailed across the High Plains in December. The wettest areas included the Dakotas, Wyoming, and central Colorado, which received approximately 200-400 percent of normal precipitation for the month. Meanwhile, below-normal precipitation occurred throughout much of Kansas and central Nebraska, where December precipitation was only about 50 percent of normal, at best. Numerous locations experienced a top 10 wettest December on record, and a few places had a top 5 snowiest December as well. It was especially wet in North Dakota. Bismarck had its wettest and 2nd snowiest December on record, and it was the 4th wettest and 4th snowiest December for Grand Forks. Some notable storm systems impacted the region in December and were partially responsible for these impressive records.
- A blizzard struck northeastern North Dakota from December 5-7. According to the National Weather Service (NWS) Weather Forecast Office in Grand Forks, snow fell at a rate of nearly 2.0 inches (5 cm) per hour at one point during the storm, and winds greater than 50 mph (80 km/hr) were reported around the region, causing hazardous travel conditions. The three-day snowfall total at Grand Forks was 16.5 inches (42 cm).
- A large storm system tracked across the region on Christmas Day and the day after bringing a variety of weather conditions, including snow, freezing rain, high winds, and thunderstorms. For instance, a blizzard occurred in western and central North Dakota. The NWS Weather Forecast Office in Bismarck reported high winds and thundersnow at their office. The two-day snowfall total for the 25th and 26th in Bismarck was 12.5 inches (32 cm). To the south and east, freezing rain impacted southeastern North Dakota and northern South Dakota. Aberdeen, South Dakota crushed its daily precipitation record on the 25th, receiving 1.28 inches (33 mm) and beating the previous record of 0.36 inches (9 mm) set in 1950. According to the NWS Weather Forecast Office in Aberdeen, at one point Pierre was reporting a thunderstorm and freezing rain at the same time! The ice storm caused a power outage that affected thousands of people. In the southern part of the region, this same storm system brought thunderstorms, hurricane-force winds, and tornadoes to southern Nebraska and northern Kansas. Tornadoes are quite rare in December in this area. This storm system made it a Christmas to remember in the region!
- Despite the slow start to the snowpack season in the Rockies, ample snowfall in December allowed snowpack to recover across much of Colorado and Wyoming. These areas received approximately 150-400 percent of normal precipitation during the month, which resulted in above-normal statewide snowpack for both states. Below-normal temperatures aided in building the snowpack as well. According to the U.S. Army Corps of Engineers, Snow Water Equivalent (SWE) above Fort Peck Dam was 78 percent of average at the end of December, which was an increase from the previous month and similar to SWE levels of 2001, the lowest snowpack year of the last 20-year period. However, snowpack fared better between Fort Peck and Garrison Dams, as SWE increased to 105 percent of average. Normally by January 1, about 44 percent of the peak mountain SWE has occurred in both reaches.
- December brought about both improvements and degradations in drought conditions throughout the High Plains region. Overall, drought conditions improved as the area in drought or abnormal dryness (D0-D4) on the U.S. Drought Monitor improved from nearly 60 percent to about 50 percent over the course of the month. However, the area in severe drought (D2) increased. The drought that has been affecting the Black Hills region of South Dakota extending westward into Wyoming intensified due to a warm and dry November. However, a cooler and wetter December allowed for slight improvements in the area. One region that was drier in December was eastern Kansas, which received only about 50 percent of normal precipitation, at best. As a result, this region had been placed in the abnormal dryness category (D0) by the end of the month. The area in drought in western Kansas and eastern Colorado persisted, as it was not as wet as other locations in the High Plains in December. Several impacts were reported in eastern Colorado, such as grasses in poor condition and spotty winter wheat germination.
- The biggest improvements occurred across parts of the Dakotas and western Colorado. In the northern Plains, December precipitation was 200-400 percent of normal in many areas. A blizzard struck this region around Christmas, and despite its negative impact to travel, it provided beneficial moisture to drought-stricken areas. In western Colorado, mountain snowpack recovered quite well during December, which improved conditions there.
- For more information, please go to the High Plains Regional Climate Center Home Page.
- Southern Region: (Information provided by the Southern Regional Climate Center)
- Drought conditions over the month of December improved dramatically in the eastern states of Tennessee, Mississippi, Louisiana and Arkansas, while in Oklahoma, conditions worsened from the previous month. At the end of November, approximately half of the Southern Region was experiencing some type of drought, with much of Mississippi and Tennessee categorized under extreme drought. As of January 3, 2017, only 27 percent of the Southern Region was experiencing drought, with little to no extreme drought remaining. Much of the drought along the Gulf coast was also eradicated. Though precipitation totals in the eastern parts of the region were not high, they were much higher than in previous months. Due to below normal precipitation in Oklahoma, drought conditions deteriorated slightly with more counties now falling under severe drought.
- A tornado on December 5, 2016 in Ascension Parish caused some damage. The twister was rated EF1 with winds estimated to be 90 mph (145 kph). There were no reports of injuries or fatalities.
- On December 13, 2016, a tornado in Harrison County, Mississippi caused some damage along Bell Creek Road near the Harrison/Hancock County line. Although some structural damage was reported, much of the damage appears to be limited to trees. There were no reports of injuries or fatalities.
- A tornadic outbreak occurred on December 17. Several storms were reported in northern Mississippi and in southwestern Tennessee. Fortunately, damage was limited mostly to trees and power lines.
- For more information, please go to the Southern Regional Climate Center Home Page.
- Western Region: (Information provided by the Western Region Climate Center)
- December 1-5: Hawaii's Big Island peaks see heavy snow: Up to 35 in (89 cm) of snow was reported on Big Island volcanic summits. Sections of Hawaii Volcanoes National Park were closed above Red Hill Cabin.
- December 7-8: Ice storm and low elevation snow in Oregon: A strong storm brought a wintery mix to low elevations of Oregon. Accumulating snow and up to 0.75 in (19 mm) of ice accumulation was reported in Portland leading to power outages, traffic accidents, and airport delays.
- December 9-10: Atmospheric river impacts Sierra Nevada and western Nevada: A warm winter storm brought heavy snow and then rain to the Sierra Nevada, with snow levels rising to over 8,000 ft (2400 m). This created dangerous avalanche conditions and one death was reported at the Mount Rose ski resort (skier was in a closed area) in Nevada. The Truckee River reached minor flood stage and minor flood impacts were reported in Truckee, California and around the Reno, Nevada area.
- For more information, please go to the Western Regional Climate Center Home Page.
For the eighth consecutive month, the Northeast averaged out to be warmer than normal. The December average temperature of 29.3°F (-1.5°C) was 0.8°F (0.4°C) above normal. Maine was the only cooler-than-normal state at 1.0°F (0.6°C) below normal. Average temperatures for the other states ranged from 0.4°F (0.2°C) above normal in New Hampshire to 1.8°F (1.0°C) above normal in West Virginia.
The Northeast received 3.77 inches (95.76 mm) of precipitation, 108 percent of normal, in December. The twelve states were split between drier than normal and wetter than normal, with totals ranging from 81 percent of normal in Rhode Island to 131 percent of normal in West Virginia.
The U.S. Drought Monitor 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. During the month, abnormally dry and drought conditions generally remained unchanged or improved across most of the region. Areas that saw conditions deteriorate included portions of southeastern Massachusetts, central Delaware, and southern and coastal New Jersey. The U.S. Drought Monitor released on December 29 indicated 44 percent of the Northeast was in a moderate, severe, or extreme drought, with another 27 percent being abnormally dry. Streamflow was generally near to below normal for the Northeast during December. As of December 29, the salt front on the Delaware River was 5 miles (8 km) upstream from its normal December location compared to 21 miles (34 km) on December 1. While water levels of some wells returned to near normal, many remained below normal in the drought-stricken areas. Some reservoirs saw an uptick in water levels, but overall they also remained below normal. For instance, Worcester, Massachusetts. reservoir was at 52.8 percent of capacity as of December 11, which is up from 52.1 percent on December 1, but below the December 1 average of 80.3 percent. As of December 30, the New York City reservoir system was at 64.8 percent of capacity compared to the normal 87.5 percent. Due to low streamflow and a drop in groundwater levels, western and central Maryland were placed in a Drought Watch. Mifflin, Juniata, Snyder, and Union counties in Pennsylvania were placed in a Drought Warning on December 16.
A lake-effect event dropped up to 25 inches (64 cm) of snow on portions of Pennsylvania and New York from December 14 to 15. Wind gusts up to 68 mph (30 m/s) accompanied the snow, creating poor visibility, especially in New York.s Wayne, Cayuga, and Oswego counties where blizzard warnings were in place. Numerous accidents occurred, including a pile-up involving nearly 60 vehicles on Interstate 80 west of Dubois, Pennsylvania. A storm system brought mixed precipitation and wind gusts of up to 60 mph (27 m/s) to the region from December 16 to 18. Storm totals included up to 9 inches (23 cm) of snow, up to 3 inches (76.2 mm) of rain, and up to 0.40 inches (1 cm) of ice accumulation. The rain contributed to flooding in portions of West Virginia and Pennsylvania, while icy conditions contributed to power outages, flight cancellations, and hundreds of accidents in Maryland. For instance, on December 17, there was a pile-up on Interstate 95 near Baltimore, Maryland involving 55 vehicles that killed two people and injured at least a dozen. In Massachusetts, the winds brought down trees and wires. A Nor.easter brought snow and wind gusts of up to 53 mph (24 m/s) to New England from December 29 to 30. Thundersnow was reported in some areas. Up to 27 inches (69 cm) of snow fell in Maine, where more than 100,000 customers lost power.
Mean temperatures ranged from near average to well above average across the Southeast region during December. The greatest departures in mean temperature were found across Florida, as well as central and southern portions of Alabama and Georgia. Monthly departures were 4 to 8°F (2.2 to 4.4°C) above average in these areas. At least 18 long-term (i.e., period of record equaling or exceeding 50 years) stations in Florida observed December mean temperatures that were ranked within the top 3 warmest values on record. Fort Myers, FL (1892-2016), Miami, FL (1895-2016), and Key West, FL (1873-2016) observed their second warmest December mean temperature on record, while Tampa, FL (1890-2016) and Vero Beach, FL (1942-2016) observed their third warmest December mean temperature on record. Unseasonably warm daytime maximum and nighttime minimum temperatures were recorded at numerous locations in Florida during the month. Clermont 9 S, FL (1948-2016), located about 20 miles southwest of Orlando, observed its highest daily maximum temperature on record for December, reaching 90°F (32.2°C) on two days during the month (5th and 18th). Fort Myers, FL and Miami, FL recorded their highest December count of 16 and 12 days, respectively, with a maximum temperature at or above 85°F (29.4°C). Miami also tied its third highest December count of 21 days with a minimum temperature at or above 70°F (21.1°C). Temperatures were well above average in Puerto Rico and the U.S. Virgin Islands during the month, as San Juan, PR (1898-2016) observed its warmest December mean temperature on record (80.8°F; 27.1°C). Across the Southeast, the warmest weather of the month occurred on the 18th, as unseasonably warm, moist air surged northeastward ahead of a vigorous cold front. Daytime maximum temperatures exceeded 70°F across much of the region, with several locations in Florida reaching 85 to 90°F. Augusta, GA (1874-2016) observed its highest daily maximum temperature on record for December (84°F; 28.9°C), and Miami, FL tied its highest daily minimum temperature on record for December (79°F; 26.1°C). In contrast, the coldest weather of the month occurred on the 16th, as an Arctic high pressure system ushered in unusually cold air across the northern portion of the region. Nighttime minimum temperatures fell below 32°F (0°C) across much of the region north of Florida, but the coldest air was confined to Virginia, where several locations reached the single digits F (-17.2 to -12.8°C).
Precipitation was highly variable across the Southeast region during December, with several extremes recorded. The driest locations were found across much of central and northern Florida, as well as portions of a broad area extending northeastward from central Alabama to northern Virginia. Monthly precipitation totals were between 5 and 50 percent of normal in these areas. Venice, FL (1955-2016) observed its driest December on record, with only 0.04 inches (1.0 mm) of precipitation. Naples Municipal Airport, FL (2002-2016) recorded its longest streak of 60 days with no measurable precipitation, ending on the 5th of the month. In contrast, the wettest locations were found across southeastern Florida, a narrow strip of northern Florida, and a broad area extending northeastward from coastal Alabama to southeastern North Carolina. Monthly precipitation totals ranged from 150 to 400 percent of normal in these areas. Camilla 3 SE, GA (1938-2016) observed its wettest December on record, with 11.09 inches (282 mm) of precipitation. Over 60 percent of the monthly total was recorded on the 6th, as Camilla observed its wettest day for any month on record, with 6.75 inches (171 mm) of precipitation. Chipley, FL (1939-2016) also observed its wettest day for any month on record, with 9.60 inches (244 mm) of precipitation on the 6th. Early on the 17th, an ice storm produced numerous transportation impacts across portions of northern Virginia and the Washington, D.C. area. Freezing rain accumulations up to a quarter of an inch caused Washington Dulles Airport and segments of Interstate 95 and the Beltway to close for several hours, with one fatality occurring in a 23-vehicle pileup in Fairfax, VA. While freezing rain accumulations were much less (0.01.0.05 inches; 0.3.1.3 mm) in the Triangle region of North Carolina (i.e., Raleigh, Durham, and Chapel Hill), over 200 vehicle accidents were reported in Raleigh, with at least 26 involving injuries. Very little snowfall was observed across the region, with the greatest monthly total of only 4.1 inches (104 mm) recorded on Beech Mountain, NC. Precipitation was highly variable in Puerto Rico and the U.S. Virgin Islands during December, with monthly departures ranging from less than 25 percent of normal in southwestern Puerto Rico to more than 400 percent of normal in the west-central portion of the island.
There were only 18 severe weather reports across the Southeast during the month, which is well below normal (based on the median frequency of 52 reports for December during 2000.2015). All but three of the reports were for thunderstorm wind gusts. Late on the 17th, thunderstorm winds estimated at 65 mph damaged trees and power poles near Waterloo, AL, as a squall line moved through the area. Only three tornadoes (2 EF-0s and 1 EF-1) were confirmed across the region during the month, which is well below the median frequency of 9 tornadoes observed during December. An EF-0 tornado touched down in Vina, AL on the 18th, resulting in damage to several buildings and athletic fields at the local high school. Early on the 29th, a nocturnal EF-1 tornado touched down near Jefferson, GA and caused minor damage to several homes. On the 12th, a man was killed by a lightning strike while standing outside his home near Molino, FL. This is the first December lightning fatality in the United States since 1998, when a man was struck inside a home under construction in Paradise Valley, AZ.
Drought conditions improved significantly across the western half of the region during December. The coverage of extreme-to-exceptional (D3.D4) drought across the Southeast decreased from 36 percent on November 29th to 21 percent on December 27th. Indeed, extreme-to-exceptional drought in Alabama and Georgia decreased by nearly 45 and 13 percent, respectively, during the month. Exceptional drought conditions were removed from the Carolinas, while severe-to-extreme (D2.D3) drought was eliminated from the Florida Panhandle and southwestern Virginia. While the rainfall during December suppressed lingering wildfires, streamflow and lake levels were slower to respond in some areas from the long-term effects of the drought. Some improvement in pasture conditions was reported in drought-stricken portions of the region, but many pastures reached dormancy before the arrival of beneficial rainfall. Livestock producers continued to provide a supplemental feeding for their herds, with many producers concerned about the potential for severe hay shortages later this winter. Small grains and forage were not able to be planted in many areas due to insufficient soil moisture and a persistent lack of rainfall during the planting window. A prevalence of foggy mornings during mid-December increased disease pressure on vegetable crops across portions of southern Florida.
With the exception of north and central Oklahoma, December was the fourth consecutive warmer than normal month for the Southern Region. In fact, all states except for Oklahoma this past month, experienced a warmer than normal month from September through December. Temperature anomalies did vary spatially across the region in December, with the southern half of the region averaging between 2-4 degrees F (1.11-2.22 degrees C), and the northern half of the region averaging between normal and 2 degrees F (0 and 1.11 degrees C) above normal. The statewide monthly average temperatures were as follows: Arkansas reporting 42.30 degrees F (5.72 degrees C), Louisiana reporting 54.70 degrees F (12.61 degrees C), Mississippi reporting 49.80 degrees F (9.89 degrees C), Oklahoma reporting 38.60 degrees F (3.67 degrees C), Tennessee reporting 40.90 degrees F (4.94 degrees C), and Texas reporting 49.60 degrees F (9.78 degrees C). The state-wide temperature rankings for May are as follows: fiftieth warmest for Arkansas, nineteenth warmest for Louisiana, thirtieth warmest for Mississippi, fifty-second coldest for Oklahoma, forty-second warmest for Tennessee, and twentieth warmest for Texas. All state rankings and records are based on the period spanning 1895-2016.
December precipitation totals in the Southern Region varied spatially bringing with them a mixed bag of wetter than normal conditions in some counties, and drier than normal conditions in other counties. Along the south western Texas coast, precipitation totals varied between 150 to 200 percent of normal. To the north in central Texas and in Oklahoma, precipitation was scarce, with most stations only reporting between 5 to 50 percent of normal precipitation. This was also the case throughout most of northwestern Arkansas. Although precipitation was slightly below normal in the northern half of the state of Mississippi, the amount of precipitation was enough to help alleviate drought conditions. Near normal precipitation in western and central Tennessee, combined with above normal precipitation in eastern Tennessee also helped alleviate drought. The state-wide precipitation totals for the month are as follows: Arkansas reporting 3.58 inches (90.93 mm), Louisiana reporting 6.01 inches (152.65 mm), Mississippi reporting 4.93 inches (125.22 mm), Oklahoma reporting 0.75 inches (19.75 mm), Tennessee reporting 6.79 inches (172.47 mm), and Texas reporting 2.05 inches (52.07 mm). The state precipitation rankings for the month are as follows: for Arkansas it was the forty-sixth driest, for Louisiana it was the thirty-fifth wettest, for Mississippi it was the fifty-seventh driest, for Oklahoma it was the twentieth driest, for Tennessee it was the twenty-third wettest, and for Texas it was the forty-second wettest. All state rankings are based on the period spanning 1895-2016. `Significant Events for December 2016
Much of the West saw above normal precipitation for the month of December, with the main exceptions being Washington, interior Montana and coastal sections of California and Oregon. The Pacific Northwest and northern Rockies experienced well below normal temperatures, while temperatures in much of Arizona and New Mexico were well above average.
December was an active weather month over the West characterized by a persistent stronger than normal jet stream over the northern half of the US and two major atmospheric river events during the first half of the month. These were both inland penetrating atmospheric rivers that brought widespread heavy rain and snowfall from California all the way to the Rocky Mountains of Wyoming and Montana. Jackson, Wyoming, had its sixth wettest December since records began in 1905 with 3.22 in (81.79 mm), 210% of normal. Elko, Nevada had its eighth wettest December on record with 2.83 in (71.88 mm), 236% of normal. Records for Elko began in 1888. Above average precipitation was also found in the Sierra Nevada. Blue Canyon, California, received 15.39 in (390.91 mm), 134% of normal, This brought some improvement of drought conditions to the region; however, the warm nature of the atmospheric river storms produced high snow levels and snow water equivalent actually decreased in mid-to- low elevation locations over the course of the month. For example, the Tahoe Basin went from 119% of normal snow water equivalent on December 1 st 2016 to 62% of normal on January 1 st 2017.
Precipitation was generally below normal in Washington, most notably east of the Cascade Range. Ephrata, Washington, recorded 0.32 in (8.13 mm) of precipitation, 26% of normal. A small region in southwest Nevada, east of the White Mountains, did not benefit from the atmospheric river storms and reported drier than normal conditions. Dyer, Nevada, recorded only 0.08 in (2.03 mm) for the month, 24% of normal.
A cold, and somewhat dry, continental polar air mass was in place over much of the Pacific Northwest and Montana during early and mid-December, producing below normal temperatures. Many locations had one of their top-10 coldest Decembers on record. Baker City, Oregon recorded its coldest December at 14.7 F (-9.6 C), 10.1 F (5.6 C) below normal. Records at Baker City date back to 1943. Great Falls, in north-central Montana, saw its 5 th coldest December in an 80-year record at 14.3 F (-9.8 C), 10.5 F (5.8 C) below normal, Much of Arizona and New Mexico, as well as sections of coastal California observed above normal temperatures. Albuquerque, New Mexico, observed an average temperature of 49.7 F (9.8 C), 2.9 F (1.6 C) above normal, and San Diego, California, recorded 66.3 F (19.1 C), 2.4 F (1.3 C) above normal.
Temperatures in Alaska were well below normal during the first half of the month and above normal the second half of the month. Interior and southern portions of the state were 3-6 F (1.7 C to 3.3 C) below normal, while the west coast and North Slope were 3-8 F (1.7-4.4 C) above normal. Temperatures at Utqiaġvik, on the North Slope, were 7.9 F (4.4 C) above normal, while at the other end of the spectrum, Kenai saw a departure of 6.1 F (3.4 C) below normal. December in Alaska was quite dry in the southern and southeastern portions of the state and for the Interior and North Slope precipitation was well above normal. Fairbanks led the way with 1.96 in (50 mm) precipitation, 306% of normal and the 4 th wettest December since records began in 1904. Unlike previous winters, the precipitation in the mainland all fell as snow. In Hawaii, Maui and the Big Island experienced well above normal precipitation with Hana recording 19.4 in (492.8 mm), 278% of normal and the wettest December since records began in 1950. Oahu and Kauai saw significantly below normal precipitation; Lihue recorded 1.17 in (30 mm) rainfall, 23% of normal and the 10 th driest December since records began in 1950.Significant Events for December 2016