000 FGUS74 KLZK 011816 CCA ESFLZK ARC001-005-009-011-013-019-021-023-025-029-031-039-041-043-045-047- 049-051-053-055-059-063-065-067-069-071-075-079-083-085-089-095-097- 099-101-103-105-109-113-115-117-119-121-125-127-129-135-137-141-145- 147-149-070000- HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE LITTLE ROCK AR 1200 PM CST THU MAR 01 2012 ...SPRING FLOOD OUTLOOK FOR MUCH OF ARKANSAS... THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN LITTLE ROCK HAS A HYDROLOGIC SERVICE AREA WHICH IS WHOLLY LOCATED WITHIN THE STATE OF ARKANSAS. IT ENCOMPASSES AN AREA WHICH INCLUDES THE WHITE RIVER AND TRIBUTARIES FROM BULL SHOALS DAM DOWNSTREAM...THE ARKANSAS RIVER AND TRIBUTARIES FROM OZARK LOCK AND DAM DOWNSTREAM...AND THE OUACHITA RIVER AND TRIBUTARIES FROM THE HEADWATERS TO THE UPPER BOUNDARY OF THE FELSENTHAL NATIONAL WILDLIFE REFUGE. ALONG WITH THE MAIN STEM OF THESE RIVERS...IT ALSO INCLUDES TRIBUTARIES WITH FORECAST LOCATIONS ON THE CACHE...BLACK...SPRING...SALINE...PETIT JEAN...FOURCHE LAFAVE...LITTLE MISSOURI...BUFFALO...LITTLE RED...MULBERRY...AND ELEVEN POINT RIVERS. ...EXISTING CONDITIONS... PRECIPITATION - 2011 ENDED WITH ABOVE NORMAL RAINFALL ACROSS NORTHERN AND CENTRAL ARKANSAS. NORTHEAST ARKANSAS SAW THE MOST IMPRESSIVE AMOUNTS FOR THE YEAR...PUTTING THAT AREA IN THE 125 TO 150 PERCENT OF NORMAL. THERE WERE SOME BELOW NORMAL TOTALS SOUTH OF LITTLE ROCK WHERE DROUGHT CONDITIONS CONTINUED THROUGH THE END OF THE YEAR. THE NEW YEAR BEGAN WITH WITH MILD TEMPERATURES AND SEVERE WEATHER. THERE WAS NOT MUCH PRECIPITATION...WITH ONLY ONE BIG RAIN EVENT IN AN OTHERWISE DRY MONTH OF JANUARY. THERE WAS A LIGHT SNOW EVENT IN THE MIDDLE OF THE MONTH. HOWEVER...LIQUID EQUIVALENT WAS NOT MUCH. THERE WAS SOME RELIEF BY FEBRUARY WHEN SPRINGLIKE CONDITIONS STARTED EARLY. SEVERAL ROUNDS OF WEATHER SYSTEMS BROUGHT ABOVE NORMAL PRECIPITATION IN NORTH...WEST...AND NORTHEASTERN ARKANSAS. SOUTHERN ARKANSAS SAW SOME IMPROVEMENT...BUT REMAINS BELOW SEASONAL AVERAGES. SOIL MOISTURE - SOIL MOISTURE CONDITIONS ARE GENERALLY REFLECTIVE OF THE RECENT PRECIPITATION TRENDS. UPSTREAM...POSITIVE DEPARTURES FROM NORMAL CAN BE FOUND ACROSS PORTIONS OF THE MIDDLE OHIO RIVER VALLEY AND SMALL AREAS OF THE UPPER MISSOURI RIVER BASIN. SIGNIFICANT NEGATIVE DEPARTURES ARE STILL PRESENT IN THE UPPER MISSISSIPPI BASIN WHERE PRECIPITATION VALUES HAVE BEEN BELOW NORMAL FOR THE LAST SEVERAL MONTHS...KEEPING THE SNOWPACK BELOW NORMAL FOR THE WINTER SEASON. SOIL MOISTURE VALUES ARE NEAR NORMAL OVER MUCH OF THE OHIO AND TENNESSEE RIVER BASINS. LONG TERM SOIL MOISTURE CONTENTS HAVE BEEN BELOW NORMAL OVER THE OUACHITA AND PORTIONS OF THE ARKANSAS RIVER BASIN...REFLECTING THE BELOW NORMAL PRECIPITATION. HOWEVER...NEAR SURFACE SOILS IN NORTHEAST ARKANSAS ARE FAIRLY MOIST ON ACCOUNT OF THE RECENT HEAVY RAIN AND MINOR RIVER FLOODING. IN THIS PARTICULAR AREA OF THE STATE WETTER SOILS ARE MORE CONDUCIVE TO FLOODING...AS LESS RAIN IS ABSORBED INTO THE GROUND. THIS ALLOWS MORE RAIN TO RUN OFF INTO THE STREAMS. RIVER FLOWS AND RESERVOIRS - STREAMFLOWS ARE SLIGHTLY BELOW NORMAL FOR THE WHITE AND BLACK RIVER BASINS. OVERALL SOIL MOISTURE CONTENT IS GENERALLY NORMAL WITH A MARKED DECLINE OVER THE LAST 30 DAYS DUE TO THE LACK OF WIDESPREAD PRECIPITATION EVENTS. NO FLOODING IS OCCURRING IN THE BLACK OR WHITE RIVER BASINS. FLOODING IS NOT EXPECTED DURING THE NEXT SEVERAL DAYS. OBSERVED DAILY STREAMFLOWS AS A PERCENT OF MEAN ARE GIVEN BELOW. 2/15 2/28 BLACK RIVER BLACK ROCK AR 126% 86% WHITE RIVER NEWPORT AR 141% 78% BASED ON EXISTING SOIL MOISTURE...STREAMFLOWS...AND NORMAL SPRING RAINFALL PATTERNS...AN AVERAGE FLOOD POTENTIAL IS EXPECTED OVER THE BLACK AND WHITE BASINS. PERCENT OF AVAILABLE FLOOD CONTROL STORAGE FOR THE BLACK/WHITE BASIN RESERVOIRS ARE GIVEN BELOW. 2/15 2/28 BULL SHOALS RES. AR 100% 100% NORFORK RES. AR 100% 100% GREERS FERRY RES. AR 100% 100% SOIL MOISTURE CONDITIONS ARE NEAR NORMAL OVER MUCH OF CENTRAL ARKANSAS...BUT BELOW NORMAL IN THE UPSTREAM PORTIONS OF THE RIVER WEST OF THE ARKANSAS/OKLAHOMA STATE LINE. OBSERVED FLOW ALONG THE LOWER ARKANSAS RIVER IS CURRENTLY NEAR 17000 CFS WHICH IS 22% OF NORMAL COMPARED TO THE LONG TERM AVERAGE OF 76000 CFS FOR EARLY MARCH. BASED ON CURRENT SOIL MOISTURE...STREAMFLOWS AND NORMAL SPRING RAINFALL PATTERNS...AN AVERAGE FLOOD POTENTIAL IS EXPECTED OVER THE LOWER ARKANSAS BASIN. STREAMFLOWS ARE NEAR NORMAL FOR THE UPPER SECTIONS OF THE OUACHITA BASIN DECREASING TO SLIGHTLY BELOW NORMAL DOWNSTREAM INTO LOUISIANA. OVERALL SOIL MOISTURE CONTENT IS GENERALLY BELOW NORMAL. NO FLOODING IS OCCURRING IN THE OUACHITA BASIN. FLOODING IS NOT EXPECTED DURING THE NEXT SEVERAL DAYS. OBSERVED PERCENT OF NORMAL STREAMFLOWS ARE GIVEN BELOW. 2/28 OUACHITA RIVER CAMDEN AR 105% BASED ON EXISTING SOIL MOISTURE...STREAMFLOWS...AND NORMAL SPRING RAINFALL PATTERNS...AN AVERAGE FLOOD POTENTIAL IS EXPECTED OVER THE OUACHITA BASIN. PERCENT OF AVAILABLE RESERVOIR FLOOD CONTROL STORAGE ARE GIVEN BELOW. 2/28 LAKE OUACHITA AR 100% DEGRAY RES. AR 100% LAKE GREESON AR 100% ...METEOROLOGICAL OUTLOOK... A WEAKENING LA NINA IS PRESENT ACROSS THE EQUATORIAL PACIFIC OCEAN. LA NINA IS EXPECTED TO WEAKEN TO NEUTRAL PHASE BY THE END OF SPRING 2012. GENERALLY RAINFALL OVER WEAKENING LA NINA OR NEUTRAL EPISODES ARE NEAR NORMAL. IN ARKANSAS...NORMAL PRECIPITATION DURING THE 3 MONTHS OF SPRING VARIES BETWEEN 14 AND 18 INCHES. THE 8-14 DAY OUTLOOK ISSUED BY THE NWS CLIMATE PREDICTION CENTER INDICATES THAT THE OUTLOOK AREA CAN EXPECT NORMAL TO ABOVE NORMAL PRECIPITATION AMOUNTS WITH THE GREATEST PROBABILITY FOR ABOVE NORMAL PRECIPITATION JUST NORTHEAST OF THE HYDROLOGIC SERVICE AREA IN THE OHIO AND TENNESSEE RIVER BASINS. TEMPERATURES OVER THIS REGION ARE EXPECTED TO BE NEAR TO SLIGHTLY ABOVE NORMAL. THE 30-DAY TEMPERATURE AND PRECIPITATION OUTLOOK INDICATES TEMPERATURES OVER THE REGION ARE EXPECTED TO BE NORMAL TO SLIGHTLY ABOVE NORMAL. THE PRECIPITATION OUTLOOK FOR THE REGION INDICATES NORMAL TO SLIGHTLY ABOVE NORMAL CHANCES OF PRECIPITATION FOR THE WHITE RIVER BASIN WITH GREATER CHANCES OVER THE OHIO RIVER BASIN. THE ARKANSAS AND OUACHITA RIVER BASIN IS FORECAST TO HAVE EQUAL CHANCES OF ABOVE...BELOW...OR NORMAL PRECIPITATION AMOUNTS. FINALLY...THE 90-DAY TEMPERATURE OUTLOOK INDICATES A NEARLY IDENTICAL PATTERN AS THE 30-DAY OUTLOOK WITH NEAR NORMAL TO SLIGHTLY ABOVE NORMAL CONDITIONS ACROSS THE REGION. HOWEVER...THE PRECIPITATION FORECAST IS LESS CERTAIN WITH EQUAL CHANCES OF ABOVE...BELOW...OR NORMAL PRECIPITATION AMOUNTS FOR THE CENTRAL PART OF THE COUNTRY. ...CONCLUSION... WEAKENING LA NINA CONDITIONS ARE OCCURRING WHICH CAN PRODUCE A PERIOD OF EARLY SPRING SEVERE WEATHER IN ARKANSAS. DURING THESE PERIODS OF HIGHLY CONVECTIVE SEVERE WEATHER...IMPRESSIVE QUANTITIES OF RAINFALL CAN OCCUR IN A SHORT PERIOD AND OVER SMALLER WATERSHEDS. LOCALIZED...HIGH INTENSITY RAINFALL CAN CREATE FLASH FLOODING AT ANY TIME...EVEN DURING PERIODS OF DROUGHT. THIS SPRING FLOOD POTENTIAL OUTLOOK DEFINES LONG TERM RIVER FLOODING...AND DOES NOT ASSESS THE RISK OF SHORT TERM FLOODING. AS FAR AS LONG TERM RIVER FLOODING IS CONCERNED...THERE ARE NO INDICATIONS OF EXTREME HYDROLOGIC CONDITIONS TO ALTER THE FLOOD POTENTIAL ACROSS THE REGION. THE COMBINATION OF LOW SNOWPACKS IN THE UPPER BASINS...NEAR NORMAL SOIL CONDITIONS...LOW TO NEAR NORMAL STREAMFLOW...AND A FORECAST OF SLIGHTLY ABOVE AVERAGE RAINFALL...IT GIVES REASON TO BELIEVE THAT AT LEAST AN AVERAGE FLOOD POTENTIAL EXISTS THIS SPRING. GIVEN THAT MARCH...APRIL...AND MAY ARE GENERALLY THE THREE WETTEST MONTHS OF THE YEAR...SOME LEVEL OF FLOODING CAN BE EXPECTED EVEN IN A NORMAL SPRING. THIS INCLUDES WIDESPREAD MINOR FLOODING AT TIMES OF HEAVIEST SPRING RAINS. THIS IS TYPICAL IN THE FLASHIER RIVERS OF THE WHITE RIVER BASIN...LOWER WHITE RIVER...CACHE RIVER...AND ALONG THE TRIBUTARIES OF THE ARKANSAS AND OUACHITA RIVER SYSTEMS. THE SPRING POTENTIAL OUTLOOK IS A ROUTINE PRODUCT. SHOULD EXCESSIVE RAINFALL BECOME PART OF THE FORECAST AT ANY OTHER TIME...A HYDROLOGIC OUTLOOK WILL BE ISSUED WITH EVENT SPECIFIC INFORMATION. ALSO LOOK FOR RIVER FLOOD ADVISORIES OR FLOOD WATCHES. FOR THE LATEST RIVER STAGE INFORMATION...FORECAST...AND WARNINGS PLEASE VISIT OUR WEBSITE AT: HTTP://WWW.SRH.NOAA.GOV/LZK RIVER STAGE AND FORECAST DATA CAN BE OBTAINED BY SELECTING THE RIVERS AND LAKES AHPS LINK UNDER THE CURRENT CONDITIONS SECTION. $$ 61