FXUS25 KWNC 251535 PMDDRO US DROUGHT MONITOR DISCUSSION NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830 AM EST WED 25 NOV 2009 NATIONAL DROUGHT SUMMARY NOVEMBER 24, 2009 THE NORTHEAST: MILD, UNSETTLED CONDITIONS PREVAILED, WITH WEEKLY RAINFALL TOTALS EXCEEDING AN INCH FROM NORTHEASTERN PENNSYLVANIA INTO CENTRAL MAINE. FOR THE SECOND STRAIGHT WEEK, HOWEVER, RAIN BYPASSED WESTERN PENNSYLVANIAS D0 /ABNORMAL DRYNESS/, WHERE 7-DAY AVERAGE STREAMFLOWS AND SOIL MOISTURE LEVELS REMAINED BELOW THE 30TH PERCENTILE. CONSEQUENTLY, THERE WERE NO CHANGES TO THE CURRENT DROUGHT DEPICTION IN THE NORTHEAST. THE MID-ATLANTIC AND SOUTHEAST: A PAIR OF UPPER-AIR LOWS GENERATED ADDITIONAL RAINFALL ON THE HEELS OF LAST WEEKS HEAVY DOWNPOURS, BRINGING FURTHER RELIEF FROM LINGERING LONG-TERM DRYNESS /D0/ IN THE CAROLINAS. CONCERNS REGARDING GROUNDWATER TABLES AND LONG-TERM PRECIPITATION DEFICITS /180- AND 365-DAYS/ REMAIN, ESPECIALLY IN SOUTH-CENTRAL NORTH CAROLINA AND NORTHEASTERN SOUTH CAROLINA. SHORT-TERM DRYNESS CONTINUED IN CENTRAL AND SOUTHERN FLORIDA, WHERE MODERATE DROUGHT /D1/ EXPANDED SLIGHTLY WESTWARD FROM THE EAST-CENTRAL COAST. IN CONTRAST, POCKETS OF HEAVY RAIN /LOCALLY MORE THAN 3 INCHES/ IN NORTHERN FLORIDA PROVIDED RELIEF FROM ABNORMAL DRYNESS /D0/. THE DELTA: SHOWERS RETURNED TO THE DELTA, EASING SHORT-TERM /30-DAY/ DEFICITS NEAR THE MOUTH OF THE MISSISSIPPI RIVER. DROUGHT IS NOT A CONCERN IN THE NORTHERN DELTA, WHERE FLOODING AND FIELDWORK DELAYS HAVE BEEN PROMINENT. TEXAS: HEAVY RAIN ACCOMPANIED A SLOW-MOVING STORM SYSTEM OVER SOUTHERN AND EASTERN TEXAS, REDUCING DROUGHT INTENSITY AND COVERAGE OVER THE SOUTHERN THIRD OF THE STATE.THREE INCHES OF RAIN /OR MORE/ WAS OBSERVED FROM CORPUS CHRISTI TO GALVESTON BAY, EXTENDING INLAND ALMOST TO SAN ANTONIO. MANY AREAS SOUTH OF VICTORIA REPORTED OVER 5 INCHES OF RAIN /LOCALLY UP TO 10 INCHES/, RESULTING IN 1- AND 2-CATEGORY IMPROVEMENTS IN DROUGHT INTENSITY. HOWEVER, THE CORE D3 /EXTREME DROUGHT/ BETWEEN DEL RIO AND SAN ANTONIO RECEIVED SCATTERED, MOSTLY LIGHT SHOWERS /LESS THAN HALF AN INCH/, WITH LITTLE CHANGE MADE TO THIS AREA. DESPITE THE RECENT HEAVY RAIN, LONG-TERM DEFICITS PERSIST, WITH 365-DAY DEPARTURES STILL GREATER THAN 10 INCHES ACROSS SOUTHERN-MOST PORTIONS OF TEXAS. MEANWHILE, WESTERN AND NORTHERN TEXAS REMAINED UNFAVORABLY DRY; DROUGHT COVERAGE /D0 AND D1/ INCREASED AROUND LUBBOCK, WHERE 90-DAY PRECIPITATION DEFICITS HAVE CREPT ABOVE 3 INCHES /LESS THAN 40 PERCENT OF AVERAGE/. CENTRAL AND NORTHERN PLAINS: DRY, WARMER-THAN-NORMAL WEATHER CONTINUED DURING THE PAST WEEK. ABNORMALLY DRY /D0/ DESIGNATION WAS INTRODUCED TO EASTERN MONTANA AND ADJACENT PORTIONS OF NORTHERN COLORADO, WHERE 30- AND 90-DAY PRECIPITATION STOOD AT APPROXIMATELY 20 AND 60 PERCENT OF NORMAL, RESPECTIVELY. PRECIPITATION TOTALS REMAINED AT OR ABOVE AVERAGE OVER THE CENTRAL GREAT PLAINS IN BOTH THE SHORT AND LONG TERM. UPPER MIDWEST: A SMALL POCKET OF LOCALLY HEAVY SHOWERS /GREATER THAN 1 INCH/ IN CENTRAL WISCONSIN PROVIDED ISOLATED RELIEF TO LINGERING LONG-TERM DRYNESS /D0/, BUT MOST OTHER DROUGHT AREAS IN THE UPPER MIDWEST WERE GENERALLY PRECIPITATION-FREE DRY DURING THE PAST WEEK. FOR THE SECOND STRAIGHT WEEK, TEMPERATURES AVERAGED MORE THAN 10 DEGREES F ABOVE NORMAL FROM THE DAKOTAS INTO WISCONSIN. THE WEST: LOCALLY HEAVY RAIN AND MOUNTAIN SNOW IN NORTHERN CALIFORNIA AS WELL AS WESTERN PORTIONS OF WASHINGTON AND OREGON PROVIDED FURTHER RELIEF FROM HYDROLOGICAL DROUGHT. THE ADDITIONAL RECHARGE TO MOUNTAIN SNOWPACKS IN NORTHERN PORTIONS OF THE WEST WAS IN SHARP CONTRAST TO WORSENING DROUGHT ACROSS THE SOUTHERN HALF OF THE REGION. PRECIPITATION DEPARTURES, ALREADY ENHANCED BY A WEAK AND ERRATIC MONSOON, HAVE INCREASED AS PACIFIC STORMS TRACK PRIMARILY ACROSS THE NORTHWEST. EXPANSION OF DROUGHT FROM THE SOUTHERN GREAT BASIN TO THE MEXICO BORDER WAS BASED ON NUMEROUS INPUTS, INCLUDING, BUT NOT LIMITED TO: UPDATED SOIL MOISTURE PERCENTILES /NLDAS/, WHICH ARE IN THE LOWEST 5TH PERCENTILE IN SOUTHEAST NEVADA AND NORTHERN ARIZONA; SNOW WATER EQUIVALENT, WHICH IS LESS THAN 50 PERCENT OF NORMAL OVER MUCH OF THE REGION; STANDARDIZED PRECIPITATION INDICES /SPI/, WHICH FOR THE CURRENT WATER YEAR /SINCE OCTOBER 1/ ARE BELOW -1.5 /D3/ IN ARIZONA AND SOUTHERN UTAH AND ARE YEAR-TO-DATE BELOW -1.5 FOR MOST OF THE SOUTHWEST. THE SITUATION ACROSS THE SOUTHWEST AND FOUR CORNERS REGION WILL CONTINUE TO BE MONITORED, WITH ADDITIONAL CHANGES TO THE DROUGHT DESIGNATION LIKELY IF THE DRY WEATHER PATTERN PERSISTS INTO THE WINTER. HAWAII, ALASKA AND PUERTO RICO: SHOWERS WERE OBSERVED IN HAWAIIS UPSLOPE LOCALES, ALTHOUGH MOST DROUGHT AREAS REMAINED DRY. DRY, BITTERLY COLD CONDITIONS WERE OBSERVED IN ALASKA, WITH NO CHANGE MADE TO THE CURRENT D0 AREA. IN PUERTO RICO, ANOTHER ROUND OF MODERATE TO HEAVY RAIN /1-4 INCHES, LOCALLY MORE/ PROVIDED ADDITIONAL RECHARGE TO STREAMFLOWS ACROSS WESTERN AND NORTHERN PORTIONS OF THE ISLAND, WHILE THE SOUTHEASTERN QUARTER OF PUERTO RICO IS STILL BEING MONITORED FOR POCKETS OF DEVELOPING DRYNESS. LOOKING AHEAD: A STRONG UPPER-AIR LOW WILL GENERATE RAIN AND SNOW ACROSS THE CENTRAL AND EASTERN CORN BELT, WITH PRECIPITATION FROM THIS FEATURE REACHING THE MID-ATLANTIC AND NORTHEAST BY FRIDAY MORNING. OVER THE WEEKEND, THIS SYSTEM WILL INTENSIFY OVER THE NORTHEAST, ACCOMPANIED BY STRONG, GUSTY WINDS AND PERIODS OF SNOW. FARTHER SOUTH, FAVORABLE SHOWERS OVER FLORIDA WILL GIVE WAY TO DRIER WEATHER BY THE WEEKEND, WHILE HIGH PRESSURE MAINTAINS SUNNY SKIES FROM THE DELTA INTO THE FOUR CORNERS AND SOUTHWEST. IN CONTRAST, RAIN AND SNOW WILL RETURN TO THE NORTHWESTERN QUARTER OF THE NATION BY WEEKS END. THE GREAT PLAINS WILL REMAIN MOSTLY DRY, ALTHOUGH SOME SNOW MAY SPILL INTO NORTHERN PORTIONS OF THE REGION OVER THE WEEKEND. THE CPC 6-10 DAY FORECAST /NOVEMBER 30 DECEMBER 4/ CALLS FOR BELOW-NORMAL TEMPERATURES OVER MOST OF THE CONTIGUOUS U.S., WITH NEAR- TO ABOVE-NORMAL TEMPERATURES CONFINED TO THE WEST COAST AND ALASKA. ABOVE-NORMAL PRECIPITATION IS ANTICIPATED ACROSS THE EASTERN QUARTER OF THE NATION, WHILE DRIER-THAN-NORMAL CONDITIONS ARE LIKELY IN THE NORTHWEST. 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. $$