Drought - April 2019


Issued 13 May 2019
Contents Of This Report:
Map showing Palmer Z Index
Percent Area of U.S. in Moderate to Extreme Drought, Jan 1996 to present
Map showing drought in the U.S.-Affiliated Pacific Islands

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 April 30, 2019
The U.S. Drought Monitor drought map valid April 30, 2019.

The upper-level circulation during April was very active with numerous Pacific weather systems moving in the jet stream flow. These took the form of upper-level short-wave troughs as well as closed lows. There were two main storm tracks — one along the U.S.-Canadian border which brought above-normal precipitation to the northern tier states. Another tracked from the Southwest, across the southern Plains, then northeastward. Surface weather systems along the southern track tapped Gulf of Mexico and Atlantic moisture to spread above-normal precipitation across the southern Plains to Midwest and East Coast. The month was drier than normal across parts of California to the central Plains, and over parts of the northern Plains and Southeast. The storm track directed some weather systems into the Alaska panhandle, where some stations were wetter than normal for the month, but the precipitation did little to alleviate long-term deficits. It was a drier-than-normal month across parts of Hawaii, Puerto Rico, and the U.S. Virgin Islands, while El Niño and post-El Niño-like conditions continued to dry out the western and northern parts of the U.S.-Affiliated Pacific Islands (USAPI). Like the last couple months, the precipitation across the CONUS this month fell on many areas that were in drought, so drought contraction outweighed expansion. Drought and abnormal dryness contracted across much of the western and southern drought areas, as well as parts of Hawaii and Puerto Rico. Abnormal dryness or drought expanded in other parts of the Plains and Southeast, as well as parts of the USAPI, Hawaii, and Puerto Rico. As a result, the USDM-based national moderate-to-exceptional drought footprint across the CONUS contracted from 5.7 percent of the CONUS at the end of March to 2.3 percent of the CONUS at the end of April (from 5.4 percent to 2.6 percent for all of the U.S.). According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 2.5 percent of the CONUS was in moderate to extreme drought at the end of April, decreasing from the end of March.

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.






Drought conditions at the end of the month, as depicted on the April 30th, 2019 USDM map, included the following core drought and abnormally dry areas:



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 (as well as wet spell conditions) in some parts of the country 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 wet conditions occurred in the Pacific Northwest, and near-normal to wet short-term conditions occurred across much of the West, that were in drought or recovering from drought at the end of March, continuing to shrink the long-term drought and expand areas that are now considered wet. Short-term dry conditions occurred in parts of the central Plains and Mid-Atlantic regions, reducing previous areas of long-term wet spell conditions.



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. Parts of the Pacific Northwest were dry at the 2- to 24-month time scales. Parts of the northern Plains were dry at the 2-, 9-, and 24-month time scales. Parts of the Texas Gulf Coast, Southeast, and Appalachians were dry at the 2-month time scale. Much of the Southeast was very dry at the 3-month time scale. Parts of Wyoming were dry at the 9-month time scale. Parts of the central Plains, and a small area in the Mid-Atlantic, were dry at the 1-month time scale. Parts of California were dry at the 1-month time scale, but the state was wet at other time scales. Parts of the Southwest are still significantly dry at the 24-month time scale. Extremely wet conditions dominate much of the country east of the Rockies at the 3- to 24-month time scales.


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



Regional Discussion


Hawaii percent of normal precipitation map, March-April 2019
Hawaii percent of normal precipitation map, March-April 2019.

Hawaii:

April was drier than normal across most of the Hawaiian Islands. A dry March helped spread dryness across the Hawaiian Islands for the last 2 months. Drier-than-normal conditions dominated for the last 3 to 7 months, with wetter-than-normal conditions dominating at the longer time scales (precipitation anomaly maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months). Streamflow was mostly below normal on Oahu and Molokai and above normal on Maui and the Big Island. Observers in Hawaii's driest areas have reported degradation in the condition of pastures and other vegetation. Ranchers in the Honokaa and Ookala areas and over the upper slopes of Mauna Kea reported hauling water for cattle due to poor pasture conditions early in the month. Dry conditions have been a contributing factor to recent brush fires outside of Honolulu. Moderate to severe drought expanded to about 37 percent of the state on the April 30th USDM map, with abnormal dryness to severe drought contracting to about 77 percent.



Alaska climate division precipitation rank map, May 2018-April 2019
Alaska climate division precipitation rank map, May 2018-April 2019.

Alaska:

April was drier than normal across western and some central portions of Alaska, and near to wetter than normal in the south and east. The precipitation anomaly pattern was mixed for the last 2 months, but dryness in the southeast — especially the panhandle — became evident at the 3-month and longer time scales (low elevation station precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months) (high elevation SNOTEL basin map for last 7 months) (gridded precipitation percentile maps for the last 1, 3, 4 months) (climate division precipitation maps for the last 1, 3, 4, 6, 12 months) (Leaky Bucket model precipitation percentile map for March). Temperatures during April were near to warmer than normal, with progressively warmer-than-normal temperatures across the state (except the panhandle), and some record-warm temperatures, at longer time scales (low elevation station temperature maps for the last 1, 2, 3, 4, 7, 12 months) (gridded temperature percentile maps for the last 1, 3, 4 months) (climate division temperature maps for the last 1, 3, 4, 6, 12 months) (Leaky Bucket model temperature percentile map for March). Snow pack was below average in much of the south due mostly to the warmer-than-normal conditions, but also due to dryness in the southern panhandle. Streamflow (for those streams that weren't frozen over) was mostly near to above normal. Abnormally dry to severe drought conditions continued in the panhandle, with about 5.8 percent of the state in abnormally dry to severe drought conditions on the April 30th USDM map.



Puerto Rico percent of normal precipitation map, March-April 2019
Puerto Rico percent of normal precipitation map, March-April 2019.

Puerto Rico:

April 2019 was wetter than normal in southeastern and some northwestern portions of Puerto Rico, but drier than normal in other portions of Puerto Rico and in the U.S. Virgin Islands. The pattern for the last 2 months was similar, except wetter in western Puerto Rico. There were a few more areas of wetness on Puerto Rico at 3 and 4 months, but dryness was more widespread at 6 and 7 months across Puerto Rico and continued on the U.S. Virgin Islands. Dry conditions were more concentrated in the southwest to central areas of Puerto Rico at 9 to 12 months. Wetter-than-normal conditions dominated at longer time scales (radar-based precipitation anomaly estimates for the last 1, 2, 3, 4, 6, 7, 12 months) (low elevation station precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months). Soils continued dry across much of the island in the south and central to east, and some streams had below-normal flow. Low aquifer levels were among several drought-related problems in portions of south-central Puerto Rico. As seen on the April 30th USDM map, moderate drought expanded to cover about 16 percent of the island, with abnormal dryness to moderate drought contracting to about 44 percent of Puerto Rico.



CONUS State Precipitation Ranks:

Map showing March 2019 state precipitation ranks Map showing February-April 2019 state precipitation ranks

Map showing May 2018-April 2019 state precipitation ranks

A wet circulation pattern has persisted across much of the CONUS for the last 12 months. The specific areas affected have varied enough from month to month so that no states have had a top ten dry rank during this period. The April drier-than-normal area in the central Plains was large enough to encompass three states, with Colorado, Nebraska, and Kansas ranking in the driest third of the 125-year historical record. Four states (Washington in the northwest and Florida, Georgia, and South Carolina in the southeast) ranked in the driest third of the historical record for February-April. Washington, Georgia, and South Carolina were so ranked for January-April. Only Washington was in the driest third of the historical record for November-April, while Oregon joined Washington for the last 12 months (May-April). At the other end of the spectrum, several states were record wet for May-April.


Agricultural Belts


Primary Hard Red Winter Wheat Belt precipitation, April, 1895-2019
Primary Hard Red Winter Wheat Belt precipitation, April, 1895-2019.
Primary Hard Red Winter Wheat Belt precipitation, October-April, 1895-2019
Primary Hard Red Winter Wheat Belt precipitation, October-April, 1895-2019.

April 2019 was drier and near to warmer than normal across most of the Primary Hard Red Winter Wheat agricultural belt. The month ranked as the 52nd driest and 42nd warmest April, regionwide, in the 1895-2019 record.

October marks the beginning of the growing season for the Primary Hard Red Winter belt. October 2018-April 2019 was wetter and cooler than normal across most of the region. The 7-month period ranked as the ninth wettest and 39th coolest October-April, regionwide.

Primary Corn and Soybean Belt precipitation, April, 1895-2019
Primary Corn and Soybean Belt precipitation, April, 1895-2019.
Primary Corn and Soybean Belt precipitation, March-April, 1895-2019
Primary Corn and Soybean Belt precipitation, March-April, 1895-2019.

April 2019 had mixed precipitation and temperature anomaly patterns across the Primary Corn and Soybean agricultural belt. The month ranked as the 30th wettest and 50th warmest April, regionwide, in the 1895-2019 record.

March marks the beginning of the growing season for the Primary Corn and Soybean agricultural belt. March-April 2019 was colder than normal across the region with a mixed precipitation anomaly pattern. The 2-month period ranked as the 30th wettest and 51st coldest March-April, regionwide, in the 1895-2019 record.


The wet conditions during April and preceding months have all but eliminated drought, and kept it from redeveloping, in the major agricultural regions of the CONUS. As of April 30th, drought was affecting only one percent of the nation's cattle inventory and none (zero percent) of the hay acreage and corn, soybean, spring and winter wheat production. According to April 28th U.S. Department of Agriculture (USDA) reports, only eight percent of the nation's winter wheat was in poor to very poor condition, and eight percent of the nation's topsoil and seven percent of the nation's subsoil were short to very short of moisture (dry to very dry). The states having the driest soils were in the Southwest and Southeast.


NOAA Regional Climate Centers:


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


As summarized by the High Plains Regional Climate Center, flooding and snowstorms continued to impact the High Plains region into April, and the temperature pattern changed for much of the region during the month, with above-normal temperatures returning to the majority of the High Plains. Mountain snowpack continued to be near to above normal throughout much of Colorado and Wyoming during April.

Many agricultural fields were ruined and will not be planted this year, as the receding floodwaters left behind sand and garbage. Cold and wet soils have delayed planting this year across the region. Areas faring worst were the Dakotas, where persistent cold and snow, as well as flooding, prevented producers from getting out into the fields. According to the April 30th edition of the USDA Weekly Weather and Crop Bulletin, for the week ending April 28th only seven percent of North Dakota's sugar beet acreage had been planted, which was far behind the five-year average of 39 percent. In South Dakota, only seven percent of the oats acreage had been planted compared to the five-year average of 62 percent, with similar statistics for spring wheat acreage. Farther south in Nebraska and Kansas, warm and dry conditions in April allowed producers to catch up, with the percent of corn acreage planted only slightly behind by the end of the month. Winter wheat was faring well across the region for the most part. It was a particularly good year for the crop in Colorado, as 76 percent of the winter wheat acreage was rated good to excellent.

Due to the cold start to spring this year, freeze damage appears to be unlikely throughout the region. According to the National Phenology Network, leaf-out occurred a couple of weeks later than normal for much of the High Plains, which is an indicator that spring arrived late this year. Due to cold temperatures and snow cover, soils have been slow to warm up, which has delayed spring planting throughout the region but especially across the Dakotas.

Both wet and dry conditions existed throughout the High Plains during April. Pockets of wetness could be found in western areas of Wyoming and Colorado, as well as across much of South Dakota. Otherwise, dryness was present in an area stretching from eastern Colorado through Nebraska and Kansas. As a result, a few locations ranked among the top 10 for driest April. Pueblo, Colorado and McCook, Nebraska had their 6th driest April on record, while it was the 10th driest for Goodland, Kansas. These areas were excessively wet during March, so dry conditions were beneficial for allowing floodwaters to recede and fields to dry out to prepare for spring planting.

Areas of the High Plains experienced both improvements and degradations in drought conditions during April, although the overall coverage decreased. Over the course of the month, the area experiencing abnormal dryness or drought (D0-D4) decreased from approximately 11 percent to 9 percent. The area in drought (D1-D4) decreased from two percent to about a half of a percent. According to the USDM, this is the least amount of drought the High Plains region has experienced since 2017 when the May 16th map indicated only 0.11 percent of the region in D1-D4. In fact, national coverage of drought hit a historic low in April, with the USDM indicating the least amount of drought in the contiguous U.S. since its inception in 1999. Thanks to a continuation of good snowpack conditions in Colorado, moderate drought (D1) was confined to a small area in the southwestern portion of the state, and abnormally dry conditions (D0) were reduced as well. Above-normal precipitation in April allowed for the elimination of D1 and reduction of D0 in western Wyoming. However, the Bighorn Mountains in north-central Wyoming missed out on precipitation and Snow Water Equivalent was below normal, prompting the introduction of D1 conditions in the area. Other areas of the High Plains that have missed out on precipitation during the past few months include northwestern North Dakota and a small pocket of south-central Kansas, where D0 conditions were introduced during April.

As explained by the Southern Regional Climate Center, temperatures for the month of April varied spatially across the Southern region. Precipitation was above normal across much of the region. Parts of western Oklahoma as well as far northern, far western, and southeastern Texas received 50 percent or less of normal precipitation. Parts of far western Oklahoma received 25 percent or less of normal precipitation. In contrast, parts of western, central, southern, northern, and eastern Texas, southern, central, and eastern Oklahoma, southwestern, central, and eastern Tennessee, and most of Arkansas, Louisiana, and Mississippi received 150 percent or more of normal precipitation. Parts of western, central, northern, and eastern Texas, southwestern Oklahoma, southern Arkansas, northern, central, and southern Louisiana, and central and northwestern Mississippi received precipitation 200 percent or more of normal. Parts of western and central Texas received precipitation 300 percent or more of normal. This was the ninth wettest April on record for the Southern region.

At the end of April, drought conditions both improved and degraded across parts of the Southern region. Severe drought classifications are no longer present, with conditions having improved substantially across southern Texas to the point where severe drought classifications were removed. Moderate drought classifications were still present in parts of southern Texas, with new areas appearing in western Texas and southeastern coastal Mississippi. However, conditions improved to the point where moderate drought classifications were removed across parts of southern Texas. There were no drought conditions in Oklahoma, Tennessee, Louisiana, and Arkansas. There was a decrease in the overall area experiencing abnormally dry conditions, as areas in northern, southern, and central Texas as well as southern Louisiana saw improvement. However, abnormally dry conditions developed across parts of eastern Texas.

As described by the Midwest Regional Climate Center, April temperatures for the region came in right at normal. Three states were below normal, five were above normal, and Illinois came in at normal. April precipitation for the Midwest was 108 percent of normal, at 0.25 inch above normal. Two states, Missouri at 78 percent of normal and Iowa at 82 percent of normal, were drier than normal while the other seven states were above normal. The current year-to-date, January to April, precipitation ranks as the 7th wettest in history (1895-2019) with 133 percent of normal for the period. May 2018 to April 2019 ranks as the wettest May to April period on record for the Midwest with over 45 inches (1143 mm). Spring planting was held up due to wet and cold conditions in the region. Corn planting was running behind the 5-year average in all nine states. Even normal precipitation would delay field work as soils are saturated with standing water in many fields.

Drought has been absent from the Midwest throughout 2019, a record 18 straight weeks (USDM history started in 2000). The most recent Midwest drought in the USDM was depicted in southwestern Missouri on December 25, 2018. The lack of drought and even abnormally dry areas in the Midwest for the past 10 weeks is also unprecedented in the USDM history. The most recent abnormally dry area in the Midwest was a small area in northwestern Minnesota in the February 19, 2019 USDM. Prior to this stretch there were only two other weeks, one week in May 2002 and another in May 2017, where the 9-state Midwest had neither drought nor abnormally dry anywhere in the region.

As noted by the Southeast Regional Climate Center, temperatures were above normal across the Southeast this April and near normal in Puerto Rico. Precipitation varied across the region for the month, with the wettest locations receiving up to 200 percent of their normal precipitation in parts of western North Carolina, northwestern Georgia, Alabama and southeastern Puerto Rico. The driest locations ranged from 10 to 70 percent of normal in parts of southeastern Georgia, central and eastern Florida, and northern Puerto Rico. Precipitation in Puerto Rico showed much variability, with Juncos, PR (1931-2019) being 4 inches (102 mm) above normal and San Juan, PR (1898-2019) being 1.63 inches (41 mm) below normal. St. Croix, PR (1951-2019) ranked as the 8th driest April on record, as measurable precipitation was only observed once during the month, April 22nd. The last time this occurred was in 1997.

Drought conditions changed little across the region for the month of April. Moderate drought (D1) covered about 8 percent of the Southeast (down from 9 percent at the beginning of the month), in an area stretching from the South Carolina coast towards east/central Georgia and from southern Alabama to the western part of the Florida Panhandle. Abnormally dry (D0) conditions covered about 30 percent of the region from the southern coastal area of North Carolina, southward through most of South Carolina, southern Georgia, southeastern Alabama and the Florida Panhandle. A small part of the eastern coast of Florida also saw abnormally dry (D0) conditions. Drought conditions expanded in Puerto Rico, with around 16 percent in moderate drought (D1), and 44 percent in abnormally dry (D0) conditions. In Georgia, agricultural producers made a lot of progress this month in crop planting and chemical treatments. Some farmers were able to get in their first cutting of hay.

As explained by the Northeast Regional Climate Center, the Northeast's average temperature for April was 47.4 degrees F (8.6 degrees C), 1.4 degrees F (0.8 degrees C) above normal; it was the 18th wettest April since 1895 for the Northeast with 4.62 inches (117.35 mm) of precipitation, 126 percent of normal. While the Northeast started April free of drought and abnormal dryness, below-normal precipitation and low streamflow led to the introduction of abnormal dryness in western New York and central West Virginia by mid-month. The USDM released on April 11 showed 3 percent of the Northeast as abnormally dry. Precipitation during the following week allowed abnormal dryness to be erased in central West Virginia and to improve slightly in western New York. The USDM released on April 18 showed less than 1 percent of the Northeast as abnormally dry. Conditions eased in New York so that by month's end the region was once again free of drought and abnormal dryness.

As summarized by the Western Regional Climate Center, several storms tracked across the West this month, providing above-normal precipitation and drought relief to the Pacific Northwest as well as the Intermountain West. Temperatures were above normal across most of the West, with the exception the of the northern Rockies.

Precipitation was greater than 130% of normal across much of the Pacific Northwest and Intermountain West this month due to an active storm cycle. Above-normal precipitation across Oregon supported large areas of improvement in drought conditions, with only 17% of Oregon experiencing abnormally dry conditions at the end of April compared to 82% at the end of March. A few areas of the Southwest also reported above normal precipitation. Some areas of drought improvement were observed in northern and central New Mexico this month; the area of the state experiencing moderate or worse drought was reduced from 39% to 23% over the course of the month. Above-normal snowpack conditions persisted through April in many western mountain ranges. The Sierra Nevada, Great Basin ranges, and Colorado Plateau had snow water equivalent values ranging from 125-200% of normal at the end of the month.

Mostly dry, spring-like conditions were observed in California during April as the area transitions into its dry season; precipitation totals are generally low during this month. Arizona also observed fairly dry conditions this month, a typically dry period following winter storms and preceding the onset of the Southwest Monsoon.

Temperatures across Alaska were warmer than normal with variable precipitation. The continued warmth across Alaska promoted ice break-up on several prominent rivers. While river break-up is not particularly uncommon during the month of April, several rivers, such as the Tanana River in central Alaska, had the earliest break-up of record by six or more days. Precipitation was well below normal across central Alaska and above normal along South Central and Southeastern Alaska. In Alaska's panhandle, Haines observed 3.95 inches (100 mm), 194% of normal; however, the panhandle as a whole remains in long-term moderate to severe drought.

Further south, precipitation was variable across the state of Hawaii. Honolulu observed 0.20 inches (5 mm) and Hilo recorded 13.51 in (343 mm), 32% and 117% of normal, respectively. This was the 8th driest March at Honolulu since records began in 1940. Drought conditions improved on the windward side of the Big Island and Maui this month, while conditions intensified on the leeward sides of nearly all islands. By the end of April, more than 37% of the state was experiencing moderate to severe drought conditions.

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 [FSM], Northern Mariana Islands, Marshall Islands [RMI], Republic of Palau, American Samoa, basinwide), April 2019 was drier than normal at Koror, Yap, Guam, Saipan, Chuuk, Pohnpei, Kwajalein, and Majuro, and near to wetter than normal at Lukonor, Kapingamarangi, Kosrae, and Pago Pago.

Inter-Tropical Convergence Zone (ITCZ) precipitation kept rainfall amounts above the monthly minimum needed to meet most water needs (8 inches) in southern parts of the USAPI, but El Niño- and post-El Niño-like conditions kept northern, western, and eastern portions dry. Monthly rainfall totals exceeded 8 inches at Lukonor, Nukuoro, Kapingamarangi, Pohnpei, Mwoakilloa, Pingelap, Kosrae (FSM); and Pago Pago (American Samoa). But the North Pacific subtropical ridge (North Pacific High) sent dry trade-winds across the northern and western regions, resulting in a dry month in terms of drought at the rest of the stations in Micronesia — Guam, Saipan, Rota (Marianas); Koror (Palau); Yap, Woleai, Fananu, Chuuk (FSM); and Ailinglapalap, Kwajalein, Jaluit, Majuro, Mili, Utirik, and Wotje (RMI). At these stations the April rainfall amounts were below the minimum thresholds (4 or 8 inches) required to meet most monthly water needs. It was a wet month (above the minimum thresholds) at Pago Pago in American Samoa, where the South Pacific Convergence Zone produced abundant rain. 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 USAPI U.S. Drought Monitor drought map valid for the end of April 2019
The USAPI U.S. Drought Monitor drought map valid for the end of April 2019.

According to the end-of-April USDM produced for the USAPI, exceptional drought (D4) has developed at Utirik and Wotje in the northern RMI and Saipan in the Marianas; extreme drought (D3) was occurring at Guam, Rota, Yap, Kwajalein, and Majuro; Fananu and Palau were experiencing severe drought (D2); moderate drought (D1) has spread into Ailinglapalap; and it was abnormally dry (D0) at Jaluit and Mili. Storage in the Majuro reservoirs steadily declined during the first half of April. Due to reservoir water rationing and a few scattered showers, storage held steady during the second half of the month, fluctuating around about 23.6 million gallons. This is about 65.6 percent of maximum, which is well below the 80 percent threshold for concern. According to reports relayed by the Guam NWS office, food sources in the northern Marshall islands are reported to be drying out. At Ebeye, health issues related to water problems have been reported. It has been reported that discarded cigarettes have caused some fires on Majuro. The Majuro dump had a large fire recently and is highly vulnerable to another. Grassland fires are possible on all of the dry islets, and they can spread rapidly with the brisk trade winds. According to an official official drought review, water catchments in the central to northern Marshall Islands are low or empty, portable Reverse Osmosis (RO) Units have been delivered and installed to 27 different locations throughout the northern atolls, and water rationing is in effect on some atolls; plants and shrubbery around households are browning and producing premature, and some inedible, harvests; and health issues have occurred due to poor water quality. Reports of damage to coconut trees from the drought in Ulithi have been received, and coconut and breadfruit in the northern islands of the FSM are drying up. A report was received that the well level at Kayangel (an atoll north of Babeldaob Island in Palau) was 5.5 feet on April 26 and has ranged between 5 and 6 feet for the month of April; the well's capacity is 7 feet. In the Marianas, Guam has seen low stream flows, large brush fires, low surface soil moisture, brown grass, and trees dying, while impacts on Saipan include numerous fires, water salinity issues, cracks in soil, and tree crops suffering (NWS Drought Information Statements for April 18 and May 2).

The dryness in parts of the RMI and the Marianas was significant. Only 0.08 inch of precipitation fell at Utirik in April, 0.08 inch in March, 0.30 inch in February, and 1.91 inches in January. That gives Utirik the driest March-April, February-April, and January-April in 13 years of data. Wotje recorded only 0.40 inch in April, 0.30 inch in March, 1.18 inches in February, and 1.93 inches in January, resulting in the fourth driest April, third driest March-April, and sixth driest January-April in 36 years of data. Saipan had 0.93 inch of rain in April, 0.53 inch in March, 1.54 inches in February, and 1.76 inches in January. This resulted in the driest February-April and January-April in 38 years of data. Guam had the third driest March-April in 63 years of data.

As measured by percent of normal precipitation, Guam, Koror, Kwajalein, Majuro, and Saipan have been drier than normal in the short term (April the last 3 months [February-April 2019], and the year-to-date [January-April]) but wetter than normal in the long term (last 12 months [May 2018-April 2019]) (the 12-month time period was missing for Koror). Kosrae was wetter than normal in the short term and drier than normal in the long term. Pohnpei and Yap were drier than normal for April and the last 3 months, but near normal for the year to date and last 12 months. Kapingamarangi and Pago Pago were wetter than normal for all 4 time periods. Chuuk was drier than normal for April but near to wetter than normal for the other 3 time periods. Lukonor was drier than normal for the last 3 and 12 months, but near to wetter than normal for the other 2 time periods. It should be noted that the monthly normal precipitation amount can vary significantly from month to month due to the strong seasonality of equatorial Pacific precipitation.

In the Marianas Islands, precipitation has been drier than normal regionwide for the last two months, and at some of the stations at longer time scales (percent of normal precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months). In the Marshall Islands, precipitation has been drier than normal regionwide for April and the last 6 months, and in the northern islands for the last 2 to 9 months (percent of normal precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36 months).


X
  • Percent of Normal Precip
  • Precipitation
  • Normals
Pacific Island Percent of 1981-2010 Normal Median Precipitation
Station Name May
2018
Jun
2018
Jul
2018
Aug
2018
Sep
2018
Oct
2018
Nov
2018
Dec
2018
Jan
2019
Feb
2019
Mar
2019
Apr
2019
May-
Apr
Chuuk124%143%107%96%158%93%142%76%183%122%175%48%114%
Guam NAS240%88%146%149%183%78%61%152%106%228%39%45%109%
Kapingamarangi92%67%142%67%128%158%223%93%195%44%197%127%112%
Koror92%66%87%N/A63%119%140%111%96%40%84%94%N/A
Kosrae136%74%106%159%65%34%58%49%93%98%143%137%83%
Kwajalein332%227%90%193%81%63%107%99%49%183%52%22%120%
Lukonor61%67%123%83%96%89%78%70%148%71%103%126%82%
Majuro216%151%142%102%94%67%69%112%93%74%102%35%104%
Pago Pago96%61%192%181%132%128%117%176%83%200%107%108%115%
Pohnpei85%92%130%166%93%100%74%100%134%79%143%66%101%
Saipan384%161%88%146%172%90%83%137%70%59%28%35%119%
Yap94%97%105%100%109%46%136%125%249%30%107%52%98%
Pacific Island Precipitation (Inches)
Station Name May
2018
Jun
2018
Jul
2018
Aug
2018
Sep
2018
Oct
2018
Nov
2018
Dec
2018
Jan
2019
Feb
2019
Mar
2019
Apr
2019
May-
Apr
Chuuk14.0116.6712.7712.3318.5510.6615.028.5318.498.8714.566.00156.46
Guam NAS8.155.4214.8421.8923.178.874.517.754.246.900.811.15107.7
Kapingamarangi11.089.1720.155.4712.6712.9820.719.1317.874.0622.5617.33163.18
Koror10.9111.6016.19N/A7.3714.1215.9212.379.793.456.246.89N/A
Kosrae24.1610.7715.8322.609.193.708.097.9215.5812.6223.0223.96177.44
Kwajalein22.3315.758.8818.818.657.0512.126.581.544.821.221.14108.89
Lukonor7.147.8319.6611.709.7910.067.127.8912.416.339.5814.30123.81
Majuro21.8116.6215.8811.9610.468.539.2912.717.235.096.743.34129.66
Pago Pago9.263.2410.689.768.6011.8311.9022.5911.1024.0411.4710.17144.64
Pohnpei16.9113.5820.1123.6111.7015.3110.9716.1317.687.5718.8412.23184.64
Saipan9.145.837.8819.1217.399.594.645.281.761.540.530.9383.63
Yap7.4111.6715.8114.8214.655.5612.0310.6815.901.574.882.92117.9
Pacific Island 1981-2010 Normal Median Precipitation (Inches)
Station Name May
2018
Jun
2018
Jul
2018
Aug
2018
Sep
2018
Oct
2018
Nov
2018
Dec
2018
Jan
2019
Feb
2019
Mar
2019
Apr
2019
May-
Apr
Chuuk11.3011.6611.9812.8611.7111.5110.6111.2510.107.258.3212.47136.77
Guam NAS3.406.1810.1414.7412.6611.447.385.114.013.032.072.5399.09
Kapingamarangi12.0813.7814.158.139.938.199.279.849.159.2711.4313.64145.85
Koror11.8317.4818.5313.5011.7711.8411.3911.1610.188.567.447.32152.90
Kosrae17.7514.6414.9114.2214.2210.9413.8316.1116.6712.9316.0617.51213.87
Kwajalein6.726.939.879.7410.7411.1811.286.663.162.642.355.2690.41
Lukonor11.6911.6515.9314.0410.1511.329.0811.278.418.939.2611.31151.36
Majuro10.1111.0111.1711.6911.1712.7313.4411.397.746.886.589.42125.25
Pago Pago9.665.335.555.386.539.2610.1412.8413.3412.0010.689.39125.57
Pohnpei19.9614.8115.4314.2612.5515.2714.8316.0813.189.5513.1718.41182.36
Saipan2.383.628.9113.1310.0910.625.613.852.532.591.892.6370.25
Yap7.8512.0415.0814.8213.5012.188.838.516.395.194.565.63120.31

The following 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, helps put the current data into historical perspective by computing ranks based on the period of record. The table below lists the precipitation ranks for April 2019, October 2018-April 2019 (the last 7 months), and May 2018-April 2019 (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.

Rank, Number of Years with data, and Period of Record for USAPI stations for April 2019, October 2018-April 2019, and May 2018-April 2019.
Rank of 1 = driest.
Station Apr 2019
Rank
Apr
No. of Years
Oct 2018- Apr 2019
Rank
Oct- Apr
No. of Years
May 2018- Apr 2019
Rank
May- Apr
No. of Years
Period of Record
Pago Pago 27 54 44 53 45 53 1966-2019
Saipan 7 39 4 30 28 30 1981-2019
Kapingamarangi 21 27 19 21 10 14 1962-2019
Kosrae 38 49 6 36 8 32 1954-2019
Lukonor 28 35 10 33 7 22 1981-2019
Nukuoro 23 36 15 34 6 33 1981-2019
Pingelap 13 35 MSG 33 MSG 31 1981-2019
Woleai 5 40 6 30 8 22 1968-2019
Yap 15 68 25 68 27 67 1951-2019
Pohnpei 16 68 31 68 29 67 1951-2019
Chuuk 10 68 43 68 55 67 1951-2019
Guam 4 63 9 62 43 62 1957-2019
Koror 25 68 26 68 MSG 66 1951-2019
Ailinglapalap 4 36 11 34 4 33 1981-2019
Jaluit 12 36 3 34 MSG 33 1981-2019
Mili 5 35 19 33 MSG 31 1981-2019
Utirik 3 18 1 8 4 4 1985-2019
Wotje 4 36 9 33 MSG 32 1981-2019
Kwajalein 6 67 7 67 51 67 1952-2019
Majuro 8 65 9 65 31 64 1954-2019

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

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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 April 2019, published online May 2019, retrieved on May 24, 2019 from https://www.ncdc.noaa.gov/sotc/drought/201904.

Metadata