000 FGUS71 KRNK 210100 ESFRNK NCZ001>006-018>020-VAZ007-009>020-022>024-032>035-043>047-058-059-WVZ 042>045-311800- HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE BLACKSBURG VA 900 PM EDT FRI MAR 20 2009 ...WINTER/SPRING FLOOD OUTLOOK...NUMBER 6 (FINAL) ...BELOW AVERAGE FLOOD POTENTIAL ACROSS THE AREA... THIS IS THE LAST IN A SERIES OF ANNUAL WINTER/SPRING FLOOD POTENTIAL STATEMENTS INTENDED TO PROVIDE INSIGHT INTO THE LIKELIHOOD OF RIVER FLOODING (NOT FLASH FLOODING) ACROSS THE BLACKSBURG HYDROLOGIC SERVICE AREA (HSA). THIS INCLUDES ALL OR PARTS OF THE JAMES ...ROANOKE...UPPER YADKIN...GREENBRIER...NEW...CLINCH AND HOLSTON RIVER BASINS IN WESTERN VIRGINIA...SOUTHEAST WEST VIRGINIA AND NORTHWEST NORTH CAROLINA. THESE STATEMENTS PROVIDE INFORMATION ON FLOOD THREAT CONDITIONS SUCH AS RECENT PRECIPITATION...SOIL MOISTURE...SNOW COVER AND ITS WATER EQUIVALENT...RIVER ICE CONDITIONS...STREAMFLOW...FUTURE PRECIPITATION AND OTHERS FACTORS. THIS OUTLOOK IS VALID FOR THE PERIOD THROUGH APRIL 3 2009. FOR THE BLACKSBURG HSA THE POTENTIAL FOR FLOODING DURING THE OUTLOOK PERIOD IS BELOW AVERAGE ACROSS MOST OF THE REGION BASED ON NEAR OR BELOW AVERAGE STREAMFLOWS...FAIRLY DRY SOILS AND A BASICALLY DRY WEATHER PATTERN FORECAST OVER MOST OF THE NEXT WEEK. IN THIS PART OF THE MID-ATLANTIC REGION...HEAVY RAINFALL IS THE PRIMARY FACTOR WHICH LEADS TO RIVER FLOODING. IT IS IMPORTANT TO NOTE THAT HEAVY RAINFALL CAN RAPIDLY CAUSE RIVER FLOODING ANY TIME OF THE YEAR...EVEN WHEN OVERALL RIVER FLOOD POTENTIAL IS CONSIDERED LOW OR BELOW AVERAGE. CURRENT FLOODING... NONE. RECENT PRECIPITATION... A PROLONGED AND WIDESPREAD RAINFALL EVENT FROM MARCH 13-17 PRODUCED FROM 1.5 TO 3.5 INCHES OF VERY BENEFICIAL PRECIPITATION ACROSS THE BLACKSBURG HSA. RAINFALL RATES WERE LIGHT TO MODERATE THROUGHOUT THE EVENT SUCH THAT NO FLOODING OCCURRED DESPITE THE FAIRLY HIGH RAINFALL TOTALS. MARCH RAINFALL IS NOW RUNNING NEAR TO SOMEWHAT ABOVE AVERAGE ACROSS THE HSA. FEBRUARY WAS VERY DRY...THE AVERAGE ACROSS THE 77 STATIONS IN THE NWS COOPERATIVE NETWORK WAS ONLY 1.19 INCHES OR 37 PERCENT OF THE FEBRUARY NORMAL OF 3.22 INCHES. JANUARY PRECIPITATION WAS VERY CLOSE TO NORMAL WITH 3.52 INCHES VERSUS THE LONG-TERM MEAN OF 3.65 INCHES. SNOW COVER... NONE. RIVER ICE... NONE. STREAMFLOW... THE RECENT RAINFALL EVENT RAISED STREAM LEVELS TO NEAR NORMAL ACROSS MOST OF THE REGION. STREAMFLOWS IN NORTHWEST NORTH CAROLINA HOWEVER HAVE DECLINED TO SOMEWHAT BELOW MEDIAN FLOWS AFTER JUST SEVERAL DRY DAYS LATE THIS WEEK. FOR MORE DETAILED INFORMATION ON STREAMFLOW CONDITIONS SEE THE USGS WATERWATCH SITE BELOW. HTTP://WATERDATA.USGS.GOV/WATERWATCH RESERVOIR CONDITIONS... MAJOR LAKE LEVELS ARE NEAR CONSERVATION POOL ELEVATIONS WITH THE EXCEPTIONS OF LAKES MOOMAW AND PHILPOTT WHICH ARE STILL BELOW NORMAL...BUT HAVE REMAINED FAIRLY STEADY IN RECENT WEEKS. RESERVOIR CURRENT POOL NORMAL POOL SMITH MOUNTAIN LAKE VA 794.50 795 CLAYTOR LAKE VA 1845.30 1846 LAKE MOOMAW VA 1575.20 1582 PHILPOTT RESERVOIR 972.72 974 BLUESTONE LAKE WV 1405.99 1410 W. KERR SCOTT NC 1030.94 1030 SOIL MOISTURE... THE PALMER DROUGHT INDEX SHOWS NEAR OR EVEN SLIGHTLY ABOVE NORMAL MOISTURE CONDITIONS AND CROP MOISTURE IS NEAR TO SLIGHTLY ABOVE NORMAL. HOWEVER THE CLIMATE PREDICTION CENTER SOIL MOISTURE MODEL IS NOW DEPICTING SOIL MOISTURE ANOMALIES OF 2 TO 3 INCHES IN THE UPPER SOIL LEVELS. THE DRIEST AREA APPEARS TO BE IN SOUTH CENTRAL VIRGINIA. FUTURE WEATHER CONDITIONS... AN UPPER LEVEL RIDGE IS FORECAST TO DOMINATE THE EASTERN U.S. MOST OF THE NEXT SEVEN DAYS WITH LITTLE IF ANY RAINFALL FORECAST BEFORE ABOUT MARCH 25 OR SO. FOR THE 6 TO 10 PERIOD MARCH 25-29 THERE IS A SOMEWHAT ENHANCED CHANCES FOR ABOVE MEDIAN RAINFALL...PRIMARILY LATE IN THE PERIOD AS THE UPPER TROUGH FINALLY REACHES THE EAST COAST. IN THE 8 TO 14 DAY OUTLOOK PERIOD...THROUGH APRIL 3 PRECIPITATION IS EXPECTED TO BE NEAR OR SLIGHTLY BELOW MEDIAN. SEE THE CPC WEBSITE FOR ADDITIONAL DETAILS: HTTP://WWW.CPC.NCEP.NOAA.GOV REPEATING THE CURRENT FLOOD POTENTIAL FOR THE BLACKSBURG HYDROLOGIC SERVICE AREA...BELOW AVERAGE. THIS IS THE FINAL SCHEDULED WINTER/SPRING HYDROLOGIC OUTLOOK FOR 2009. $$ PC