California and National Drought Summary for June 7, 2016
Summary
June 9, 2016 - Heavy rainfall in parts of the Southeast brought relief to dry areas in the Mid-Atlantic States. Parts of eastern Tennessee, western Maryland, northwest Virginia, and West Virginia all saw a one category reduction of D0-D1 areas. Other parts of the eastern U.S. didn’t fare as well. Warmer than normal temperatures and seasonally low rainfall accumulations led to the expansion of D0 in parts of central Massachusetts and western New York, the introduction of moderate drought in southern parts of New Hampshire and Maine, and the persistence of D0-D1 conditions in other areas. In the West, temperatures were 6 to 15 degrees above normal, leading to the expansion of D0 across the Pacific Northwest. Other changes include the introduction of D2 in southern Arizona and along the South Dakota-Wyoming border.The Northeast
The heavy rainfall last week missed many of the driest areas in the region. Western New York around Buffalo as well as along the east coast from Maryland to Boston generally received less than a half inch of rain, which is well below normal for this time of year. Continued above-normal temperatures (4-8 degrees) combined with below-normal streamflow called for a small expansion of D0 in localized areas in central Massachusetts and near New York’s Finger Lakes and the introduction of D1 in southeastern New Hampshire and southern Maine.The Southeast
Rainfall in excess of 4 inches in locations in central and eastern Tennessee began to ease drought conditions in these areas. An approximate four county region of D1 near the central part of the state was improved to D0 and a small section of D0-D1 in Tennessee near the North Carolina border was improved one class. Likewise, significant rainfall in western Maryland, northwest Virginia, and eastern West Virginia led to the trimming or removal of D0 there. Continued below-normal seasonal rains in northwest Georgia, northeast Alabama and extreme southeastern Tennessee have kept these areas in moderate to severe drought.The South
Nearly all of the South recorded some amount of rainfall in the last week. While D0 areas received up to an inch of rain, these amounts were generally below normal for this time of year resulting in status quo.Midwest
Continued dryness has brought an expansion of D0 in central and south central Iowa, while two plus inches of rain led to the removal of D0 in the northeastern part of the state. Similar accumulations in Minnesota’s Arrowhead Region also erased D0 there. Farther east, short-term dryness combined with well below normal stream flow values (tenth percentile or less) and well above normal temperatures (6 to 8 degrees) led to the introduction of D0 near the tri-point marker of Indiana, Michigan, and Ohio.The Plains
Texas was once again the recipient of heavy rains keeping the state drought-free. Missing out on the rains, west Texas saw some localized expansion of D0. Continued dryness has begun to stress crops near the tri-border area of South Dakota, Minnesota, and North Dakota resulting in a small pocket of D1 being introduced in the area. Likewise, the recent dryness has been affecting vegetation and raising fire concerns near the Black Hills resulting in the introduction of D2 and the expansion of D0 bleeding into northeast Wyoming, southeast Montana, and southwest North Dakota.The West
The changes on this week’s map included a deterioration in conditions in the Pacific Northwest and southeastern Arizona and improvement in southern New Mexico. Record heat (up to 12 degrees above normal) in the Northwest has resulted in early snowmelt, low stream flows, and increased evaporation leading to a push of D0 across the remainder of Oregon, Washington and the Idaho Panhandle. Long-term drought remains in California, Nevada, Arizona and New Mexico as we move into the heat of summer. Southern Arizona has missed out on the winter and spring rain, deteriorating rangeland and leading to the introduction of D2 in the area. Recent rainfall (1-4 inches) in eastern New Mexico has improved D0 in the area. Southern New Mexico has also seen improved conditions and a trimming of D1. Potential for continued increases may be in store in the coming weeks with the start of the monsoon season.Hawaii
A wet May improved vegetation conditions across many of the Islands resulting in one category improvements in Niihau, Kauai, along the slopes of Koolau Range on Oahu, eastern Maui, and the east facing slopes of the Big Island.Alaska and Puerto Rico
No changes were made this week in Alaska and Puerto Rico, so status quo rules.Looking Ahead
Next week’s forecast (June 9-16) calls for hot and relatively dry conditions as a ridge moves across the Great Plains, Mississippi Valley, Ohio Valley, and Southeast. Significant rainfall accumulations are expected across the upper Midwest as thunderstorms move through the region. The National Weather Service 7-Day forecast also calls for dryness across much of California and northwestern Montana and accumulations of generally less than a half an inch across the lower elevations of the West. The Climate Prediction Center 6-10 day outlooks call for a continuation of above normal temperatures June 14-18 across the western two-thirds of the contiguous U.S. and Alaska and a relief to the recent warmth in the Pacific Northwest and New England. As for precipitation, the odds favor above-normal accumulations in Alaska, the Pacific Northwest, the Midwest, and the South while the Plains and Northeast are likely to be below normal.Author(s):
Deborah Bathke, National Drought Mitigation Center
Mark Svoboda, National Drought Mitigation Center
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 DroughtD2 ... 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)
Source: National Drought Mitigation Center
