NWS Spring Flood Outlook
The National Weather Service in Tulsa has posted its spring flood outlook. Long and short of it: an enhanced chance of above normal precipitation for March in Northwest Arkansas.
HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
337 PM CST FRI FEB 19 2010
…SPRING FLOOD OUTLOOK FOR EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS…
SPRING FLOOD POTENTIAL…
THE POTENTIAL FOR FLOOD CONDITIONS IN EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS WILL BE NEAR AVERAGE THIS SPRING. EXCEPT FOR THE MAINSTEM OF THE ARKANSAS RIVER…FLOODING IN EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS USUALLY OCCURS IN RESPONSE TO SPECIFIC PRECIPITATION EVENTS. THE ARKANSAS RIVER MAY FLOOD IN RESPONSE TO MORE WIDESPREAD UPSTREAM CONDITIONS. THERE ARE CURRENTLY NO INDICATIONS OF EXTREME HYDROLOGIC CONDITIONS TO ALTER THE FLOOD POTENTIAL OF EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS.
BASED ON OBSERVED SOIL MOISTURE CONDITIONS…OBSERVED STREAMFLOWS AND NORMAL SPRING RAINFALL PATTERNS…AN ABOVE AVERAGE FLOOD POTENTIAL IS EXPECTED THIS SPRING OVER THE WHITE BASIN IN NORTHWEST ARKANSAS.
THIS SPRING FLOOD POTENTIAL OUTLOOK GENERALLY DEFINES THE RISK OF LONG TERM RIVER FLOODING. IT DOES NOT ASSESS THE SHORT TERM RISK OF FLOODING…PARTICULARLY FLASH FLOODING. LOCALIZED…HIGH INTENSITY RAINFALL CAN CREATE FLASH FLOODING AT ANY TIME. THIS IS TRUE EVEN DURING PERIODS OF DROUGHT.
PRECIPITATION…
WATER-YEAR /BEGINNING 1 OCTOBER 2009/ RAINFALL TOTALS ARE GENERALLY NEAR AVERAGE ACROSS EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS. HOWEVER…SOUTHEAST OKLAHOMA RECEIVED ABOVE AVERAGE RAINFALL. ACCORDING TO THE OKLAHOMA CLIMATOLOGICAL SURVEY…SOUTHEAST OKLAHOMA RECEIVED NEAR 130 PERCENT OF NORMAL RAINFALL AND IS RANKED AS THE 10TH WETTEST OCTOBER 1 THROUGH FEBRUARY 18 PERIOD SINCE RECORDS BEGAN IN 1921.
RAINFALL TOTALS OVER THE LAST 60 DAYS /21 DECEMBER 2009 TO 18 FEBRUARY 2010/ WERE ALSO NEAR AVERAGE ACROSS EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS. SOUTHEAST OKLAHOMA REMAINED ABOVE AVERAGE DURING THIS PERIOD WITH OVER 150 PERCENT OF NORMAL RAINFALL AND RANKED AS THE 12TH WETTEST PERIOD SINCE RECORDS BEGAN IN 1921 ACCORDING TO THE OKLAHOMA CLIMATOLOGICAL SURVEY.
SOIL MOISTURE CONDITIONS…
ACROSS EASTERN OKLAHOMA…SOIL MOISTURE IS GENERALLY ABOVE AVERAGE WITH SOUTHEASTERN OKLAHOMA IN THE 80-95TH PERCENTILE. SOIL MOISTURE WAS IN EXCESS OF THE 90TH PERCENTILE ACROSS THE WESTERN PORTION OF ARKANSAS. SOIL MOISTURE CONDITIONS FOR THE WHITE RIVER BASIN IN NORTHERN ARKANSAS ARE ALSO ABOVE THE SEASONAL AVERAGE.
RIVER AND STREAM CONDITIONS…
RIVERS AND STREAMS ARE FLOWING AT NEAR AVERAGE LEVELS ACROSS MOST OF EASTERN OKLAHOMA. HOWEVER THE RED RIVER IS FLOWING AT MUCH ABOVE AVERAGE LEVELS. RIVERS AND STREAMS IN WESTERN ARKANSAS ARE FLOWING AT AVERAGE TO ABOVE AVERAGE LEVELS.
LAKE AND RESERVOIR CONDITIONS…
ACCORDING TO THE U.S. ARMY CORPS OF ENGINEERS…RESERVOIRS IN THE ARKANSAS AND RED RIVER SYSTEMS WERE BOTH AVERAGING 93 PERCENT OF FLOOD CONTROL STORAGE AVAILABLE AT THIS TIME. BEAVER LAKE RESERVOIR IN THE WHITE RIVER BASIN HAS 85 PERCENT OF FLOOD CONTROL STORAGE AVAILABLE AT THIS TIME.
RECENT FLOODS…
THERE HAS BEEN NO MAINSTEM RIVER FLOODING IN EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS SO FAR IN 2010.
DROUGHT CONDITIONS…
ACCORDING TO THE U.S. DROUGHT MONITOR…NO DROUGHT CONDITIONS EXIST IN EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS.
TEMPERATURE AND PRECIPITATION OUTLOOKS…
THE MARCH OUTLOOK FROM THE CLIMATE PREDICTION CENTER /CPC/ INDICATES AN ENHANCED CHANCE FOR BELOW NORMAL TEMPERATURES AND ABOVE NORMAL PRECIPITATION ACROSS ALL OF EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS.
THE SPRING OUTLOOK FOR MARCH-APRIL-MAY FROM CPC INDICATES AN ENHANCED CHANCE FOR BELOW NORMAL TEMPERATURES AND AN EQUAL CHANCE OF ABOVE…NEAR…AND BELOW NORMAL PRECIPITATION ACROSS ALL OF EASTERN OKLAHOMA AND NORTHWEST AND WEST CENTRAL ARKANSAS. HOWEVER…THERE
IS AN ENHANCED CHANCE OF ABOVE NORMAL PRECIPITATION JUST WEST OF THE NWS TULSA HYDROLOGIC SERVICE AREA IN WESTERN AND CENTRAL OKLAHOMA.
RESOURCES…
ADDITIONAL INFORMATION ON THE SPRING FLOOD POTENTIAL AND WATER SUPPLY IS AVAILABLE AT…
WWW.SRH.NOAA.GOV/ABRFC/WATERSUPPLY/INDEX.PHP
WWW.WEATHER.GOV/TULSA
INFORMATION USED TO COMPILE THIS SPRING FLOOD POTENTIAL OUTLOOK WAS PROVIDED COURTESY OF THE ARKANSAS RED BASIN AND THE LOWER MISSISSIPPI RIVER FORECAST CENTERS…THE CLIMATE PREDICTION CENTER…THE USACE…THE USGS…THE OKLAHOMA CLIMATOLOGICAL SURVEY AND THE NATIONAL DROUGHT MITIGATION CENTER.
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© 2010, Scott Branyan