2/7 Drought Monitor - Some Improvement Around The Margins; Drought Core Holds In Plains

National Drought Summary -- February 5, 2013

The discussion in the Looking Ahead section is simply a description of what the official national guidance from the National Weather Service (NWS) National Centers for Environmental Prediction is depicting for current areas of dryness and drought. The NWS forecast products utilized include the HPC 5-day QPF and 5-day Mean Temperature progs, the 6-10 Day Outlooks of Temperature and Precipitation Probability, and the 8-14 Day Outlooks of Temperature and Precipitation Probability, valid as of late Wednesday afternoon of the USDM release week. The NWS forecast web page used for this section is: http://www.cpc.ncep.noaa.gov/products/forecasts/.

Precipitation in this U.S. Drought Monitor week was dominated by a strong frontal passage that produced a tornado outbreak on January 29-30. In the two day period, there were 78 reports of tornadoes in the NOAA Storm Prediction Center’s Storm Reports, 65 on January 29th and 13 on January 30th, all of which are considered preliminary. Tornadoes were reported in Alabama, Arkansas, Georgia, Illinois, Indiana, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, and Tennessee. Tennessee appears to have the largest number of reports at 19. There was one tornado-related fatality in Georgia, outside of Atlanta. This storm dumped above normal precipitation from the Southern Plains into the Midwest and from the Deep South through upstate New York.

The Southeast: The powerful storm on the 29th and 30th of January provided some much needed precipitation to the region. Areas of Exceptional (D3), Severe (D2) and Moderate Drought (D1) as well as Abnormal Dryness (D0) were alleviated from northeast Alabama, through northern Georgia and up the Appalachians into Virginia. Tennessee and Kentucky also saw eradication of Abnormal Dryness (D0) in the western parts of their states. Conversely, Exceptional Drought (D3) expanded in southern Georgia and Moderate Drought (D1) expanded in southern Alabama and Mississippi. Moderate Drought (D1) was introduced in South Florida.

The Northeast and Mid-Atlantic: Areas of Moderate Drought (D1) and Abnormal Dryness (D0) improved this week in Appalachian Virginia and West Virginia. All other areas remained unchanged.

The South and Southern Plains: The areas from eastern Oklahoma through Arkansas saw significant improvements in Extreme (D3), Severe (D2), and Moderate Drought (D1) and Abnormal Dryness this week with the passing of the January 29-30 storm. In southern Texas and the Oklahoma Panhandle, areas of Exceptional (D4), Extreme (D3), Severe (D2), and Moderate Drought (D1) expanded as did Abnormal Dryness (D0). In South Texas, this was largely due to dry conditions compounded by above normal temperatures and wind.

The Central and Northern Plains and Midwest: Conditions continued to improve in the Midwest. The area from Missouri up through eastern Iowa and into Illinois, Indiana, and Ohio saw relief of Severe (D2) and Moderate Drought (D1) and Abnormal Dryness (D0). Additionally, South Dakota saw small improvement in Exceptional (D4) and Extreme Drought (D3). Precipitation fell in other areas of this region but frozen soils led to high runoff and little moisture seeping in to the ground. Improvements were largely kept to areas with soil temperatures above freezing.

The West: Exceptional Drought (D4) expanded in Colorado this week while Abnormal Dryness (D0) abated in central Idaho and western Montana. Other areas of the West remained unchanged. Snowpack improved in some places this week but is still below normal across much of the West.

Hawaii, Alaska and Puerto Rico: Two weeks of decent precipitation have improved D0 to D3 conditions across the Hawaiian Islands with each Island seeing at least come improvement. Likewise, central Alaska also saw improvement in Abnormal Dryness (D0) due to enhanced precipitation. Drought conditions remained unchanged in Puerto Rico.

Looking Ahead: During the February 7-11, 2013 time period, there is an enhanced probability of precipitation moving from the West Coast early in the period, across the central U.S., and into the Midwest and Mid-Atlantic by the end of the period. Above normal temperatures are expected to move from the central U.S. early in the period to also cover the East and Gulf Coasts by the end of the period.

For the ensuing 5 days (February 12-16, 2013), the odds favor normal to above normal temperatures mostly east of the Mississippi River. Below-normal temperatures are likely from the Mississippi River to the West Coast. Precipitation is likely to be normal to above-normal from the Northern Rockies to the Southern Plains and all points eastward. Below-normal precipitation is likely along the West Coast. The odds of above-normal precipitation are greatest across the Northern Plains, into the Great Lakes, all down the East Coast, and in southern Texas. In Alaska, temperatures and precipitation are likely to be above-normal across the state.

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)



Updated February 6, 2013

EDIT/END

http://www.droughtmonitor.unl.edu/