This U.S. Drought Monitor week was dominated by a series of storm that moved across the country primarily from February 28 – March 2.  These storms dropped well over 100 tornadoes, based upon preliminary reports. According to NOAA’s Storm Prediction Center, as of March 6, there were 47 confirmed deaths in Alabama, Illinois, Indiana, Kansas, Kentucky, Missouri, Ohio, and Tennessee. 

The Southeast: Beneficial precipitation moved through some of the most intense drought areas of the Southeast this week.  Storms which brought tornadoes from Ohio and Illinois down through Alabama also brought multiple inches of rain from the panhandle of Florida up into the Delmarva Peninsula.  Areas of Exceptional Drought (D4) were alleviated in south Georgia.  Extreme Drought (D3) improved in northern Florida, Georgia, and South Carolina.  Severe Drought (D2) improved in Florida and the Carolinas.  Moderate Drought (D1) improved in southern Alabama and northern Florida.

The Northeast and Mid-Atlantic: Adequate rains fell this week the Mid-Atlantic and Northeast.  Areas of Abnormal Dryness (D0) improved in the southern Delmarva Peninsula and in southeastern Maine.

The South and Southern Plains:  With the exception of the extreme south of Texas and near New Orleans, LA, little precipitation fell in the South this week.  Minor improvements in Exceptional Drought (D3) were made around southeastern Louisiana and in south-central Texas.  The mounting lack of precipitation in western Texas and the Texas Panhandle led to expansion in all drought classes in those areas including expansion of Exceptional Drought (D4).  In Kansas, Moderate Drought (D1) and Abnormal Dryness (D0) expanded in the north-central and western part of the State.

The Northern Plains and Midwest: Conditions in the Northern Plains improved some this week with the passing of a front that dumped rain and snow across much of the region.  Moderate Drought (D1) improved in North and South Dakota and in northeast Nebraska.  Abnormal Dryness (D0) improved in South Dakota.    In the Midwest, conditions improved slightly in northwest Iowa with contraction of Severe Drought (D2).

The West: The West was generally dry this week with the exception of the extreme Northwest.  Drought conditions remain unchanged in most areas but intensified in northern Utah, in southern Oregon and near the Nevada – California border where long-term deficits are mounting.

Hawaii, Alaska and Puerto Rico: Drought conditions remained unchanged in Alaska and Puerto Rico this week. In Hawaii, precipitation on the south end of the Big Island led to improvement in Severe (D2) and Moderate Drought (D1).  Oahu saw a contraction of the Abnormal Dryness (D0) there.

Looking Ahead: During the March 8-12, 2012 time period, there is an enhanced probability of precipitation in the Pacific Northwest and ranging from the Southern Plains into the Southeast. Below normal precipitation is expected through much of the West and throughout the Great Lakes and New England.

For the ensuing 5 days (March 13-17, 2012), the odds favor normal to warmer than normal conditions over the entire US with the exception of the Pacific Coast and Alaska, where odds favor below normal conditions.  In New England, the extreme Southwest, and Alaska the odds favor below normal precipitation while the northern Pacific Coast and a large are from the South, through the Southeast and into the Ohio Valley and Midwest are expected to see above normal precipitation.

Author: Michael Brewer, National Climatic Data Center, NOAA

Dryness Categories
D0 ... Abnormally Dry ... used for areas showing dryness but not yet in drought, or for areas recovering from drought.

Drought Intensity Categories
D1 ... Moderate Drought
D2 ... Severe Drought
D3 ... Extreme Drought
D4 ... Exceptional Drought

Drought or Dryness Types
S ... Short-Term, typically <6 months (e.g. agricultural, grasslands)
L ... Long-Term, typically >6 months (e.g. hydrology, ecology)

Drought Monitor: Storms move across the country