929
FXUS25 KWNC 211222
PMDDRO
US DROUGHT MONITOR DISCUSSION
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
830 AM EST THU 21 AUG 2008
NATIONAL DROUGHT SUMMARY AUGUST 19, 2008
THE NORTHEAST: COOL, UNSETTLED WEATHER PREVAILED OVER MOST
AREAS, WITH ADDITIONAL SHOWERS IN SOUTHERN NEW JERSEY FURTHER
EASING D0 DRYNESS. RAIN CONTINUED TO BYPASS CENTRAL AND
NORTHERN PENNSYLVANIA, HOWEVER, WHICH HAS LED TO AN INTRODUCTION
OF D0 ACROSS NORTHERN PORTIONS OF THE STATE.
MID-ATLANTIC: ISOLATED, LOCALLY HEAVY SHOWERS DID LITTLE TO
OFFSET THE EXPANDING DRYNESS IN THE REGION. RAINFALL OVER
THE PAST 30 DAYS WAS LESS THAN 60 PERCENT OF NORMAL ACROSS
CENTRAL MARYLAND AND NORTHERN VIRGINIA, AND LESS THAN 30
PERCENT OF NORMAL ACROSS MUCH OF CENTRAL AND SOUTHERN VIRGINIA.
CONSEQUENTLY, THE NORTHWARD EXPANSION OF MODERATE TO SEVERE
DROUGHT CONTINUED, WITH D0 DRYNESS REACHING AS FAR NORTH
AS MARYLAND. DRYNESS ALSO EXPANDED ON THE DELMARVA PENINSULA.
SOUTHEAST: LOCALLY HEAVY RAIN IN SOUTHERN AND EASTERN AREAS
HALTED THE SOUTHWARD EXPANSION OF DROUGHT, WITH IMPROVEMENTS
NOTED FROM THE SOUTH CAROLINA COAST SOUTHWARD INTO FLORIDA.
IN THE LATTER REGION, SLOW-MOVING TROPICAL STORM FAY ERASED
LINGERING LONG-TERM DROUGHT OVER LAKE OKEECHOBEE, WITH
ADDITIONAL RAIN FROM THIS SYSTEM EXPECTED TO GRACE PORTIONS OF
THE SOUTHEAST DURING THE UPCOMING WEEK. IN CONTRAST, RAPIDLY
DECLINING STREAMFLOWS AND SOIL MOISTURE LEVELS WERE CLEAR
INDICATORS OF THE EXPANDING DROUGHT IN TENNESSEE AND KENTUCKY.
THE DELTA: WIDESPREAD SHOWERS /LOCALLY MORE THAN 3 INCHES/ LED
TO ADDITIONAL REDUCTIONS OF D0 AND D1. IN CENTRAL LOUISIANA,
HOWEVER, PERSISTENT LONGER-TERM RAINFALL DEFICITS COUPLED WITH
GENERALLY LIGHT RAINFALL /LESS THAN ONE INCH/ OVER THE PAST
WEEK LED TO ONLY MINOR MODIFICATIONS OF THE D2 DROUGHT AREA.
THE PLAINS AND MIDWEST: FAVORABLY WET WEATHER CONTINUED ACROSS
MUCH OF THE REGION, RESULTING IN ADDITIONAL DROUGHT REDUCTIONS
FROM THE DAKOTAS SOUTHWARD INTO TEXAS. IN PARTICULAR, LINGERING
D4 DROUGHT IN SOUTH-CENTRAL TEXAS WAS ERASED FOLLOWING ANOTHER
WEEK OF 1 TO 3 INCHES /LOCALLY MORE/ OF RAIN. HEAVY RAIN
/3-6 INCHES/ IN EASTERN TEXAS ERASED LINGERING DROUGHT IN
THIS REGION. HEAVY TO EXCESSIVE RAINFALL /LOCALLY MORE THAN 8
INCHES/ WIPED AWAY DROUGHT OVER THE SOUTHERN HALF OF OKLAHOMA,
WHILE MORE DROUGHT RELIEF /1-4 INCHES OF RAIN/ WAS NOTED
IN THE TEXAS AND OKLAHOMA PANHANDLES. IMPROVEMENTS NOTED IN
SOUTHERN TEXAS WERE IN RESPONSE TO ADDITIONAL RAIN AND FAVORABLE
DROUGHT INDICES. WIDESPREAD SHOWERS AND THUNDERSTORMS ALSO
EASED DRYNESS FROM SOUTHEASTERN COLORADO INTO NEBRASKA AND
WESTERN MINNESOTA. IMPROVEMENTS IN D2 AND D3 COVERAGE ACROSS
NORTHERN NORTH DAKOTA WERE THE RESULT OF RECENT RAINFALL
AND IMPROVING DROUGHT INDICATORS, SUCH AS STREAMFLOW LEVELS
AND THE VEGETATION HEALTH INDEX. IN CONTRAST, SIGNIFICANT
SHORT-TERM PRECIPITATION DEFICITS /30-DAY RAINFALL LESS THAN
50 PERCENT OF NORMAL/ ARE IMPACTING PORTIONS OF THE CORN BELT;
THE DRY CONDITIONS ARE MOST PROMINENT IN CENTRAL AND NORTHERN
MINNESOTA /D1/, WHILE D0 WAS INTRODUCED TO THE WESTERN CORN
BELT AND FROM NORTHERN WISCONSIN AND THE UPPER PENINSULA OF
MICHIGAN SOUTHEASTWARD INTO NORTHERN OHIO.
THE WEST: RANGELANDS IN NORTHERN CALIFORNIA DETERIORATED
UNDER PERSISTENT DRYNESS AND DAYTIME TEMPERATURES IN EXCESS
OF 100 F, WITH A COINCIDING EXPANSION OF D1 AND D2 DROUGHT.
THE LAST OF SOUTHERN CALIFORNIAS D0 WAS CHANGED TO D1 UNDER
A PERSISTENT DRY WEATHER PATTERN. ELSEWHERE IN THE REGION,
NO CHANGES WERE MADE TO DROUGHT DESIGNATION.
HAWAII, ALASKA AND PUERTO RICO: IN HAWAII, DECLINING PASTURE
CONDITIONS OVER SOUTH-CENTRAL MAUI AND NORTHWESTERN PORTIONS
OF THE BIG ISLAND LED TO AN INCREASE OF DROUGHT FROM D2
TO D3. DROUGHT WORSENED /TO D1/ ON LANAI DUE TO DEGRADED
PASTURE CONDITIONS AS WELL. IN CONTRAST, TRADE-WIND SHOWERS
RESUMED OVER NORTHEAST KAUAI, REDUCING D1 TO D0. MEANWHILE,
NEAR-NORMAL RAINFALL OVER THE PAST 30-PLUS DAYS ACROSS THE
EASTERN QUARTER OF THE BIG ISLAND ALLOWED FOR SOME IMPROVEMENT
HERE AS WELL /D0/. IN PUERTO RICO, D1 WAS EXPANDED SLIGHTLY
EASTWARD DUE TO SPOTTY, GENERALLY LIGHT RAINFALL AND A DECLINE
IN THE VEGETATIVE HEALTH INDEX. LOOKING AHEAD: DURING THE
NEXT 5 DAYS /THROUGH AUGUST 25/, THE FATE OF THE SOUTHEASTERN
DROUGHT WILL DEPEND LARGELY ON THE TRACK OF TROPICAL STORM FAY.
AS OF 2 PM /EDT/, AUGUST 20, THE OFFICIAL FORECAST FROM THE
NATIONAL HURRICANE CENTER TOOK FAY ON A MOSTLY WESTWARD PATH
ACROSS NORTHERN FLORIDA INTO SOUTHERN PORTIONS OF ALABAMA AND
MISSISSIPPI. ON THIS TRACK, MOST OF THE HARDEST-HIT DROUGHT
AREAS FROM NORTHERN GEORGIA INTO SOUTHWESTERN VIRGINIA WOULD
MISS OUT ON MUCH-NEEDED RAINFALL. NEVERTHELESS, ABUNDANT
TO LOCALLY EXCESSIVE RAIN WILL LIKELY BRING SIGNIFICANT
IMPROVEMENT TO SOUTHERN-MOST DROUGHT AREAS IN THE EASTERN
GULF COAST REGION, WITH FAYS REMNANTS TAKING A POSSIBLE
NORTHWARD TURN INTO THE TENNESSEE VALLEY EARLY NEXT WEEK.
FARTHER NORTH, HIGH PRESSURE WILL MAINTAIN MOSTLY DRY WEATHER
OVER THE MID-ATLANTIC, ALTHOUGH A FEW SHOWERS MAY PROVIDE SOME
MOISTURE LATE IN THE PERIOD. IN THE MIDWEST, A COLD FRONT WILL
TRIGGER SHOWERS AND THUNDERSTORMS, ALTHOUGH THE HEAVIEST RAIN
MAY END UP FALLING IN EASTERN AREAS WITH THE REMNANTS OF FAY.
LOCALLY HEAVY SHOWERS WILL CONTINUE OVER THE DELTA, WITH
MOISTURE GRADUALLY WORKING WESTWARD BACK INTO THE CENTRAL AND
SOUTHERN PLAINS OVER THE WEEKEND. OUT WEST, MOSTLY DRY, WARM
CONDITIONS WILL PREVAIL. THE CPC 6-10 DAY FORECAST /AUGUST
26-30/ CALLS FOR ADDITIONAL, MUCH-NEEDED RAINFALL OVER THE
SOUTHEASTERN QUARTER OF THE NATION AS WELL AS PORTIONS OF THE
NORTHERN PLAINS. IN CONTRAST, DRIER-THAN-NORMAL CONDITIONS ARE
EXPECTED TO PERSIST OVER SOUTHWESTERN DROUGHT AREAS AS WELL AS
CENTRAL PORTIONS OF THE CORN BELT. FAVORABLY COOLER WEATHER
IS ANTICIPATED FROM THE SOUTHERN PLAINS INTO THE SOUTHEAST,
WHILE ABOVE-NORMAL TEMPERATURES PREVAIL IN THE SOUTHWEST AND
FROM THE NORTHERN PLAINS INTO NEW ENGLAND. AUTHOR: ERIC
LUEBEHUSEN, UNITED STATES DEPARTMENT OF AGRICULTURE.
DROUGHT INTENSITY CATEGORIES...
D0 ABNORMALLY DRY...
D1 MODERATE DROUGHT...
D2 SEVERE DROUGHT...
D3 EXTREME DROUGHT...
D4 EXCEPTIONAL DROUGHT
DROUGHT TYPES...
USED ONLY WHEN IMPACTS DIFFER...
A AGRICULTURAL...
H HYDROLOGIC.
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