April - June 2013

Outlook Graphic: GIF   PDF 

Latest Seasonal Assessment - The drought outlook for March 21 - June 30, 2013 is based primarily on short-, medium-, and long-range forecasts, initial conditions, and climatology. Since the release of the previous drought outlook issued on March 7, 2013, the largest drought improvement occurred across the middle to upper Mississippi Valley and the Ozark region. Improvement is forecast to continue across these areas and extend northwest to include much of the Dakotas and Minnesota. Some improvement is forecast for the most intense drought areas of the central and southern Great Plains. Prospects for drought improvement decrease further south across the southern high Plains and Texas. Drought is forecast to persist for much of the West and expand across northern California and southern Oregon. During the past two months, major improvement occurred across Georgia and South Carolina where additional improvement is expected. Drought is forecast to persist or develop across the Florida peninsula but it will likely be short-lived as the rainy season typically begins during June. Some improvement is expected for the smaller areas of drought across northern Alaska and the Hawaiian Islands.

Tools used in the U.S. Drought Outlook (USDO) included the official CPC temperature and precipitation outlooks for April 2013 and April through June 2013, various short- and medium-range forecasts and models such as the 5-day and experimental 7-day WPC precipitation totals (released March 20), 6-10 day and 8-14 day forecasts (released March 20), the NAEFS precipitation outlooks, the soil moisture tools based on the Constructed Analog on Soil (CAS) moisture, dynamical models (CFSv2, NMME, and IMME), the 384-hour total precipitation forecasts from several runs of the GFS, the four-month Palmer drought termination and amelioration probabilities, climatology, and initial conditions. We are currently in ENSO Neutral conditions as of this forecast release date.

Frequent rainfall during February and early March resulted in major drought improvement across Georgia and South Carolina where extreme to exceptional drought has ended. Drought improvement is likely to continue with another round of widespread heavy rainfall (1 – 3 inches) forecast during the next week. Recent wetness coupled with the short-term forecast leads to improvement for Georgia and South Carolina.
Forecast confidence for Georgia and South Carolina is high.

In contrast to the wet conditions to the north, the Florida peninsula experienced drier-than-normal conditions during the past 30 days with rainfall deficits ranging from 2 to 4 inches. The three-month precipitation outlook favors below-median precipitation; however, precipitation normals increase rapidly during June. Although drought persistence and development are forecast during the next three months, the drought is expected be short-lived as the wet season begins in June.
Forecast confidence for Florida is low.

During the past 30 to 60 days, precipitation deficits increased across east Texas and northern Louisiana. The U.S. Drought Monitor released on March 21 indicates an expansion of abnormal dryness (D0) and moderate drought (D1) in this region. Development is forecast across southeast Texas where the 3-month precipitation outlook favors below median precipitation. Since the monthly and seasonal outlooks indicate equal chances across northeast Texas and northern Louisiana, development is not currently forecast for this region. Except for the Texas Panhandle during the past 30 days, precipitation has averaged at or below normal across west and central Texas. Precipitation on most time scales favoring below median precipitation along with enhanced odds for above normal temperatures during AMJ support persistence or development across west and central Texas.
Forecast confidence for Texas is moderate.

Persistence is forecast across the southern high Plains where the monthly and seasonal precipitation outlooks tilt the odds towards below median precipitation. In addition, enhanced odds for above normal temperatures are forecast from April through June for this region. Prospects for improvement increase across northeast Oklahoma due to expected rainfall during the upcoming week and equal chances for above, near, or below median precipitation forecast in the CPC monthly/seasonal precipitation outlooks.
Forecast confidence for the southern Plains is moderate.

Some improvement forecast for the northern and central Plains is based largely on the annual cycle of precipitation and the absence of a dry signal in the CPC monthly/seasonal precipitation outlooks. 40 to 50 percent of the annual precipitation occurs during AMJ across much of the northern and central Plains. The CPC seasonal outlook tilts the odds towards above median precipitation across eastern Kansas. Although the drought will likely not be eliminated during the next three months, some improvement across this region is expected. Adequate precipitation during May and June and a lack of early summer heat waves are critical for any improvement to occur.
Forecast confidence for the northern and central Plains is moderate.

Snowstorms during the past month have contributed to above median precipitation across the upper Mississippi Valley. According to the National Operational Hydrologic Remote Sensing Center on March 20, snow-water equivalent values exceed 5 inches across much of this region. It should be noted that is unclear how much of the spring runoff can recharge the dry subsoils. Due to wetness during the past month and a relatively wet time of year for AMJ, improvement is forecast for the upper Mississippi Valley. Prospects for improvement are highest across Wisconsin where drought levels are less intense and the seasonal outlook favors above median precipitation.
Forecast confidence for the upper Mississippi Valley is high.

Persistence is expected for much of Colorado, New Mexico, Utah, Nevada, and Arizona due to low snow-water equivalent values (around 75% of normal) and below average streamflows forecast for the spring and early summer. Enhanced odds for below median precipitation and above normal temperatures during AMJ also favor persistence. However, across northeast Colorado, short-term precipitation and the lack of a dry signal during AMJ lead to a forecast of some improvement.
Forecast confidence for Colorado, New Mexico, Utah, Nevada, and Arizona is high.

Similar to the interior Southwest, snow-water equivalent values are also below average across California and southern Oregon. Following a wet start to the winter, unseasonably dry conditions affected these areas during January and February. According to the U.S. Drought Monitor on March 21, abnormal dryness (DO) continues to expand across northern California and southern Oregon. Below median precipitation is favored during AMJ across these same areas. Therefore, persistence and development is forecast for this region. Precipitation typically decreases rapidly later in the spring with little to no prospects for improvement beyond April.
Forecast confidence for California and southern Oregon is high.

Snow-water equivalent values across the northern Rockies of Montana and northern Wyoming are close to average. The absence of a dry signal among the monthly/seasonal tools coupled with a relatively wet time of year result in a forecast of some improvement for the northern Rockies.
Forecast confidence for the northern Rockies is moderate.

Mountain snowpack was 50 to 75 percent of normal on March 1, 2013 across the drought area in north-central Alaska which is a slight increase from one month ago. Some improvement is forecast for this region.
Forecast confidence in Alaska is moderate.

Moderate to extreme drought covers western sections of the individual Hawaiian Islands from Oahu southeastward through the Big Island. Some drought improvement is expected throughout these areas.
Forecast confidence in Hawaii is moderate.