FXUS22 KWNC 041230
PMDDRK
US DROUGHT OUTLOOK DISCUSSION
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
 830 AM UTC THU 04 SEP 2008
 
TS FAY INFLUENCED THE DROUGHT IMPROVEMENT ACROSS THE SOUTHEAST
IN LAST MONTH’S OUTLOOK, AND NOW THE IMPACT FROM HANNA, WHICH IS
EXPECTED TO STRIKE THE SOUTH CAROLINA OR NORTH CAROLINA COAST
AS A CAT 1 HURRICANE ON SEPTEMBER 6, IS HAVING AN INFLUENCE ON
THE UPDATED DROUGHT OUTLOOK. WITH 2-4 INCHES OF RAIN FORECAST
FROM EASTERN SOUTH CAROLINA NORTHWARD THROUGH THE COASTAL
MID-ATLANTIC STATES AS OF SEPTEMBER 3, WHEN THIS FORECAST WAS
PREPARED, HANNA SHOULD BRING DROUGHT ALLEVIATION TO EASTERN
AREAS OF NORTH CAROLINA AND VIRGINIA, AS WELL AS DELAWARE AND
SOUTHERN NEW JERSEY, BUT MISS THE MORE SEVERE DROUGHT AREAS
FARTHER INLAND.  FARTHER WEST, GUSTAV’S RAINS OBLITERATED
DROUGHT IN LOUISIANA AND MAY BENEFIT DRY AREAS IN THE GREAT
LAKES REGION DURING THE FIRST DAYS OF THIS FORECAST PERIOD. IN
CONTRAST, A CORE DROUGHT AREA BETWEEN THE RAINS FROM GUSTAV
AND HANNA WILL LIKELY SEE LITTLE RELIEF EARLY ON, AND THIS
INCLUDES MUCH OF TENNESSEE, KENTUCKY, AND WESTERN PARTS OF THE
CAROLINAS AND VIRGINIA, AS WELL AS MUCH OF GEORGIA. OUT IN THE
ATLANTIC, TS IKE IS EXPECTED TO BECOME A HURRICANE SHORTLY,
AND APPEARS LIKELY TO BE APPROACHING THE FLORIDA-CUBA AREA
BY SEPTEMBER 8. THE FINAL TRACK FOR IKE IS VERY UNCERTAIN,
SO IKE’S RAINS ARE NOT EXPLICITLY CONSIDERED IN THIS DROUGHT
OUTLOOK. HOWEVER, THE ACTIVE TROPICAL SEASON SEEMS TO JUSTIFY
THE CONTINUED BROAD-BRUSH APPROACH TO DROUGHT IMPROVEMENT ACROSS
THE SOUTHEAST. AGAIN, IT SHOULD BE NOTED THAT HYDROLOGICAL
DROUGHT INDICATORS SUCH AS LARGE RESERVOIRS AND GROUNDWATER
WILL RESPOND MORE SLOWLY THAN SMALL STREAMS, SOIL MOISTURE, AND
PASTURE CONDITIONS. AS WATER DEMANDS DECREASE LATER IN THE FALL,
RESERVOIR LEVELS SHOULD SHOW GRADUAL IMPROVEMENT. AS FOR NOW,
LAKE LANIER IN NORTHERN GEORGIA IS NEAR ALL-TIME LOW STORAGE
FOR THIS TIME OF THE YEAR, AND THE RAINS FROM FAY ONLY CAUSED
A BLIP UPWARD IN ELEVATION.
CONFIDENCE FOR THE SOUTHEAST AND MID-ATLANTIC: HIGH ALONG THE
COAST, BUT MODERATE OVER THE INTERIOR
IN TEXAS, WESTERN OKLAHOMA, AND SOUTHEAST COLORADO, MEDIUM
RANGE FORECASTS AS WELL AS CLIMATOLOGY CONTINUE TO SUPPORT
IMPROVEMENT FOR LINGERING DROUGHT. CLIMATOLOGY SUPPORTS LESS
CHANCE FOR IMPROVEMENT TO THE WEST IN COLORADO, RESULTING IN
THE DEPICTION OF MORE LIMITED IMPROVEMENT IN THAT AREA.
CONFIDENCE FOR TEXAS, OKLAHOMA, AND COLORADO: MODERATE
DRY WEATHER IN AUGUST CONTRIBUTED TO PATCHY DROUGHT ACROSS THE
MIDWEST. THE OUTLOOK FOR THESE SMALL AREAS IS VERY UNCERTAIN
GIVEN FORECASTS FOR EQUAL CHANCES WET OR DRY IN THE 30 AND
90-DAY TIME FRAMES BY CPC AND MIXED MESSAGES FROM MEDIUM
RANGE INDICATORS. GIVEN MODERATE RAINS FORECAST FOR THE
FIRST 5 DAYS, WITH COOL WEATHER, THE WET FORECASTS FROM SOME
OF THE MEDIUM RANGE MODELS, AND THE CONTINUED TENDENCY FOR
THE COUPLED FORECAST SYSTEM TO LEAN WET IN THIS AREA FOR THE
SEPTEMBER-NOVEMBER 2008 PERIOD, IMPROVEMENT IS FORECAST. MOST OF
THE RAINS FROM GUSTAV ARE FORECAST TO FALL BETWEEN THE DRIEST
AREAS IN THE REGION, SO RELIEF MAY NOT BE IMMINENT. FOR THE
LONGER TERM, THE CONSTRUCTED SOIL ANALOGUES MAINTAIN DRYNESS
IN WISCONSIN TO YEAR’S END, WHILE THE LATEST GFS MODEL RUNS
SHOWS AT LEAST 3-4 INCHES OF RAIN IN THE NEXT 15 DAYS. SUCH
DIVERGING INDICATIONS KEEP CONFIDENCE LOW.
CONFIDENCE FOR THE MIDWEST: LOW
THERE WERE MINIMAL CHANGES TO THE PREVIOUS OUTLOOK FOR NORTH
DAKOTA AND EASTERN MONTANA, WITH GREATER IMPROVEMENT FORECAST
TO THE EAST AND LESS TO THE WEST. ALTHOUGH DAMP AND COOL
WEATHER SUPPORT IMPROVEMENT FOR THIS AREA IN THE FIRST 5 DAYS,
MEDIUM-RANGE FORECASTS ARE DRY AND CLIMATOLOGY SUPPORTS THE
IDEA OF RELATIVELY LESS IMPROVEMENT FROM EXTREME WESTERN NORTH
DAKOTA INTO EASTERN MONTANA. THE AREA OF DEVELOPMENT FORECAST
IN THE PREVIOUS OUTLOOK FOR WESTERN MONTANA HAS BEEN DROPPED
AS RECENT RAIN, SNOW AND COOL WEATHER MADE DROUGHT LESS LIKELY.
CONFIDENCE: LOW
ACROSS THE WEST, THE BEGINNING OF THE WET SEASON IN THE FALL
SHOULD LEAD TOWARD SOME IMPROVEMENT ACROSS NORTHERN CALIFORNIA
AND IN EASTERN WASHINGTON. IN CALIFORNIA, ALTHOUGH RAIN AND
MOUNTAIN SNOW INCREASE LATER IN THE FALL, IT WILL TAKE TIME
TO BUILD A SNOW PACK IN THE SIERRAS.
CONFIDENCE FOR THE WEST: HIGH IN HAWAII, NO CHANGES WERE
MADE TO THE PREVIOUS OUTLOOK, WITH DEVELOPMENT FORECAST
IN SOME LEEWARD AREAS AND IMPROVEMENT FORECAST IN WINDWARD
SIDES OF THE BIG ISLAND.  CONFIDENCE: MODERATE IN PUERTO RICO,
CLIMATOLOGY AND PROSPECTS FOR ABUNDANT TROPICAL RAINS IN COMING
WEEKS CONTINUE TO SUGGEST DROUGHT IMPROVEMENT.  CONFIDENCE:
HIGH FORECASTER: D. LE COMTE
 
 
 
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