FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE TALLAHASSEE FL
621 PM EST FRI MAR 10 2006
...SPRING FLOOD POTENTIAL OUTLOOK FOR SOUTHEAST ALABAMA...SOUTHWEST
AND SOUTH CENTRAL GEORGIA...AND THE FLORIDA BIG BEND AND PANHANDLE...
THE POTENTIAL FOR FLOOD CONDITIONS WILL BE NEAR NORMAL THIS SPRING.
...EXISTING CONDITIONS...
RAINFALL - PRECIPITATION RANGED BELOW NORMAL ACROSS SOUTHEAST
ALABAMA...THE FLORIDA PANHANDLE AND SOUTHWEST GEORGIA THIS WINTER.
THE EXCEPTIONS INCLUDED THE FLORIDA BIG BEND AND THE SUWANNEE
AND SANTA FE RIVER BASINS WHICH RECEIVED PERIODS OF 100 TO 200
PERCENT OF NORMAL RAINFALL DURING NOVEMBER...DECEMBER 2005 AND
FEBRUARY 2006. THE NET RAINFALL FOR THE WATER YEAR BEGINNING 1 OCT
2005 HAS RANGED MOSTLY AROUND 50 TO 75 PERCENT OF NORMAL ACROSS
SOUTHEAST ALABAMA...THE FLORIDA PANHANDLE INCLUDING THE OCHLOCKONEE
RIVER BASIN AND SOUTHWEST GEORGIA. THE WETTER AREAS OVER SOUTH
CENTRAL GEORGIA...THE FLORIDA BIG BEND AND SUWANNEE RIVER BASIN
INCLUDING THE SANTA FE RIVER RANGED FROM 75 PERCENT OF NORMAL TO NEAR
OR SLIGHTLY ABOVE NORMAL.
SOIL MOISTURE - SURFACE MOISTURE IS SLIGHTLY BELOW NORMAL
OVER SOUTHEAST ALABAMA AND SHOWS A MARKED DECREASE THE FIRST
PART OF MARCH THAT HAS EXTENDED INTO SOUTHWEST GEORGIA AND THE
FLORIDA PANHANDLE. THIS DOES NOT INCLUDE THE RAINFALL THAT OCCURRED
OVER SOUTHEAST ALABAMA TODAY. NEAR TO SLIGHTLY ABOVE NORMAL SURFACE
MOISTURE CONTINUES OVER THE REST OF THE AREA.
GROUND WATER CONDITIONS - AQUIFER WATER LEVELS ACROSS SOUTHWEST
GEORGIA ARE NEAR OR SLIGHTLY HIGHER THAN LAST YEAR. THIS INCLUDES
THE SOUTHEASTERN COASTAL PLAIN AND FLORIDIAN AQUIFER SYSTEMS.
SOME MAJOR EXCEPTIONS INCLUDE MITCHELL COUNTY NEAR BACONTON GEORGIA
WHERE THE FLORIDIAN AQUIFER MEASUREMENT AT AURORA DAIRY IS ABOUT 4
FEET HIGHER THAN LAST YEAR AT THE SAME TIME. INTERESTINGLY...GROUND
WATER LEVELS IN THE CLAYTON FORMATION NORTHWEST OF THE FLINT RIVER AT
THE RANDOLPH...TERRELL...CALHOUN COUNTY LINE ARE RUNNING NEARLY 12
FEET HIGHER THAN LAST YEAR AT THIS TIME. RIVERS IN THE SUWANNEE
BASIN SHOW SUSTAINED BASE FLOWS NEAR OR SLIGHTLY ABOVE NORMAL
INDICATIVE OF NORMAL GROUND WATER LEVELS SINCE BASE FLOWS THERE ARE
SUPPORTED BY GROUND WATER SPRINGS.
RIVER FLOWS - THOUGH RAINFALL HAS BEEN BELOW NORMAL OVER
SOUTHEAST ALABAMA...SOUTHWEST GEORGIA AND THE FLORIDA PANHANDLE...
LOWER TEMPERATURES AND REDUCED EVAPOTRANSPIRATION HAVE HELPED TO
LIMIT LOSS OF GROUND WATER. THIS IS EVIDENT IN THE GEORGIA WELL
READINGS. THOUGH RIVER LEVELS ARE 20 TO 40 PERCENT BELOW NORMAL
ACROSS THESE AREAS...RECENT RAIN EVENTS SHOW THAT STREAMS ARE STILL
RESPONSIVE TO HEAVY RAINFALL AND HAVE GOOD BASEFLOW SUPPORT FROM
GROUND WATER EVEN IN THE RELATIVELY DRIER AREAS. THE WETTEST AREAS
INCLUDING THE FLORIDA BIG BEND AND PARTICULARLY THE ST. MARKS AND
AUCILLA RIVER BASINS AND THE SUWANNEE BASIN...INCLUDING THE SANTA FE
RIVER BASIN...ALSO HAVE GOOD BASE FLOW SUPPORT AND WILL BE RESPONSIVE
TO ANY SIGNIFICANT RAINFALL EVENT.
RESERVOIR CONSIDERATIONS - POOL LEVELS ARE RUNNING VERY CLOSE TO THE
"RULE CURVE," OR TARGET LEVELS, FOR THIS TIME OF YEAR. HOWEVER,
INFLOWS INTO RESERVOIRS ARE BEGINNING TO RUN BELOW NORMAL IN SOME
CASES. IT IS DURING THIS TIME OF YEAR, MANY RESERVOIRS PLAN TO FILL
THEIR RESERVOIRS TO SUMMER LEVELS. NORMAL RAINFALL SHOULD TAKE CARE
OF THAT SITUATION.
...METEOROLOGICAL OUTLOOK...
THE CHANCES FOR RAINFALL TEND TO INCREASE IN MARCH BEFORE DRIER
CONDITIONS ARRIVE IN THE APRIL...MAY TIME FRAME. IT IS COMMON
FOR WET FRONTAL BOUNDARIES TO SLOW DOWN AND GENERATE SIGNIFICANT
RAINFALL ACROSS SOUTHERN GEORGIA AND NORTHERN FLORIDA IN MARCH. WITH
THE WEAK LA NINA CONDITIONS...THERE IS NO STRONG DRY SIGNAL IN THE
FORECAST WHICH WOULD INDICATE THAT WE WOULD AVOID A SIGNIFICANT
SPRING RAINFALL EVENT ACROSS OUR AREA. THIS WILL HAVE TO BE
MONITORED.
...LONG TERM OUTLOOK...
THE CLIMATE PREDICTION CENTER IS FORECASTING NORMAL SPRING RAINFALL
AND TEMPERATURES AND A WET AND WARM SUMMER. THOUGH RIVER FLOWS
WILL BE RUNNING LOWER LATER THIS SPRING...ABOVE NORMAL SUMMER
RAINFALL SHOULD HELP MAINTAIN RIVERS AT SLIGHTLY BELOW TO NEAR NORMAL
LEVELS THIS YEAR.
...SPRING FLOOD OUTLOOK...
A REVIEW OF HISTORICAL FLOWS CONSISTENTLY PORTRAY RISES
ON RIVERS IN OUR AREA IN THE MARCH TIME FRAME. SINCE DROUGHT
CONDITIONS ARE NOT FORECAST FOR OUR AREA...WE WILL LIKELY SEE NORMAL
RIVER RISES IN EARLY SPRING. HOWEVER SINCE FLOWS ARE WELL BELOW
NORMAL...SIGNIFICANT FLOODING IS NOT EXPECTED THOUGH MINOR FLOODING
REMAINS A POSSIBILITY.
INFORMATION USED TO COMPILE THIS FLOOD POTENTIAL OUTLOOK WAS
PROVIDED COURTESY OF THE SOUTHEASTERN RIVER FORECAST CENTER...
CLIMATE PREDICTION CENTER...THE UNITED STATES GEOLOGICAL SURVEY...
THE NORTHWEST FLORIDA WATER MANAGEMENT DISTRICT AND THE SUWANNEE
RIVER WATER MANAGEMENT DISTRICT.
FOR MORE SPECIFIC HYDROMETEOROLOGICAL DATA...VISIT OUR INTERNET
WEB SITES AT:
WWW.SRH.NOAA.GOV/SERFC
WWW.SRH.NOAA.GOV/TAE
52-LANIER
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