Tools used in the U.S. Monthly Drought Outlook (MDO) included the updated Climate Prediction Center (CPC) temperature and precipitation outlooks for March, various short- and medium-range forecasts and models such as the 7-day quantitative precipitation forecast (QPF) totals from the Weather Prediction Center (WPC), the 6-10 day and 8-14 day CPC extended-range forecasts (ERFs), the Week 3-4 CPC forecasts released on February 24, CFSv2 monthly forecasts of temperature and precipitation, the 384-hour total precipitation forecasts from several runs of the GFS, climatology for March, and recent precipitation.
According to the U.S. Drought Monitor (USDM), valid on February 21, 16.87 percent of California is designated with long-term drought and the state is currently free of extreme to exceptional drought. As of February 27, snow water content is more than 200 percent of normal throughout the Sierra Mountains. Data from the California Department of Water Resources indicates that many of the larger reservoirs throughout the state are running near or above their historical average. However, Lake Cachuma in Santa Barbara remains below average. Improvement or removal of drought over the most northern drought areas on the February 21 USDM is based on above-average precipitation during February. The 6-10/8-14 day outlooks favor below-median precipitation across southern California. Given the likelihood of a dry start to the month and the increased chances of below-median precipitation predicted by the CFS model during March, persistence is expected for the remaining long-term drought areas of southern California and Arizona.
Forecast confidence for California and Arizona is high.
Long-term drought continues across parts of western Montana and eastern Oregon. Snow water content values are currently running at or above average throughout the Pacific Northwest, northern Great Basin, and northern Rockies. Based on the favorable snowpack and a wet signal among many of the precipitation tools, removal of these small drought areas is expected by the end of March.
Forecast confidence is moderate for eastern Oregon and western Montana.
Long-term drought also continues across the northern high Plains including northeast Wyoming and western South Dakota. This area of long-term drought has changed very little during the past three months. Since March is a relatively dry month, persistence is most likely for the ongoing long-term drought across the northern high Plains.
Forecast confidence is high for the northern high Plains.
The coverage and intensity of drought remained nearly steady across the central and southern high Plains and front range of the Colorado Rockies, which is typical during the winter. Model guidance indicates little to no precipitation during the early part of the month as low pressure systems develop and track north of this region. This dry start to the month, coupled with enhanced winds and unseasonably warm temperatures, along with a relatively dry time of year favors persistence and development across the central and southern high Plains.
Forecast confidence is high for the central and southern high Plains.
Rainfall during February resulted in drought removal across southern Oklahoma, while moderate to severe drought persists across central and northeast Oklahoma. Drought generally expanded across Arkansas and Missouri during the past month. Precipitation has averaged 75 percent, or less, across most of northwest Arkansas and Missouri during the past 90 days. Maximum temperatures averaged 8 to 10 degrees F above normal, or more, across these same areas which exacerbated the dryness. The heaviest rainfall (more than 0.50 inches) during the next week is expected to occur across the Ohio Valley. During March, the CFS model generally favors below-median precipitation and above-normal temperatures across the ongoing drought areas of Arkansas, Missouri, and Oklahoma. Therefore, drought persistence is expected with drought development most likely across parts of Missouri, eastern Kansas, and adjacent areas of Oklahoma where short-term precipitation deficits are increasing.
Forecast confidence is moderate for Arkansas, Missouri, Kansas, and Oklahoma.
Small areas of moderate to severe drought exist across parts of south Texas. Drought removal and improvement for the northern most drought area is based on rainfall during the next week along with a slight tilt in the odds for above-median precipitation predicted by the CPC monthly outlook. Elsewhere, persistence is forecast for south Texas.
Forecast confidence is low for south Texas.
Although drought ended this past month across central Georgia, long-term drought persisted and expanded across the southern Appalachians and parts of parts of Alabama and Mississippi. 180-day precipitation deficits are generally more than 8 inches across these long-term drought areas. The CPC 8-14 day outlook indicates enhanced odds for below-median precipitation across this region. March is typically one of the wetter months of the year across the interior Southeast. Despite this favorable climatology, persistence is expected for a majority of the Southeast drought area due to the duration of the drought and the lack of a wet signal during the first two weeks of the month. The most likely area for removal is northeast Mississippi and extreme northern Alabama due to expected rainfall early in the month.
Forecast confidence is low for the interior Southeast.
Short-term drought developed across most of the southern half of the Florida peninsula. Persistence is forecast as March is one of the drier months of the year. Short-term drought is expected to expand north across central Florida due to a lack of rainfall during early March. Additional development across extreme southern Florida is not expected due rainfall that occurred during late February.
Forecast confidence is high for Florida.
Moderate drought and abnormal dryness expanded across the mid-Atlantic this past month due to below-average precipitation coupled with unseasonably warm temperatures during late February. For example, Washington, D.C. received only 0.34 inches of precipitation through February 27 which is more than 2 inches below normal for the month to date. Temperatures are running 8.4 degrees F above normal for the month to date, likely making February 2017 the warmest on record. Persistence and additional development is based on the very dry February followed by expected below-normal precipitation in early March.
Forecast confidence is moderate for the mid-Atlantic.
Although parts of the Northeast experienced drought removal during the past month, moderate to extreme long-term drought continues from eastern Pennsylvania and New Jersey northeast to New England. 90-day precipitation has generally averaged near normal for these areas, but 180-day precipitation deficits continue. A rapid snow melt across southern New England during late February was unfavorable for recharge of ground water. Drought removal is forecast for central Pennsylvania, the Hudson River Valley and Vermont due to recent precipitation and expected precipitation during the first week of March. Given the long-term duration of the drought, persistence is expected for the majority of remaining drought areas across the Northeast.
Forecast confidence is moderate for the Northeast.
Heavy rainfall at the beginning of March is expected to end drought across the Big Island of Hawaii. Drought is not expected to develop across Alaska or Puerto Rico through the end of March
Forecast confidence is high for Hawaii, Alaska, and Puerto Rico.
Forecaster: Brad Pugh
Next Monthly Drought Outlook issued: March 31, 2017 at 3pm EDT