PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT FRI AUG 31 2007 30-DAY OUTLOOK DISCUSSION FOR SEPTEMBER 2007 DURING AUGUST 2007 NEGATIVE EQUATORIAL SEA SURFACE TEMPERATURE (SST) ANOMALIES IN THE EASTERN EQUATORIAL PACIFIC EXPANDED WESTWARD AND NOW EXTEND FROM THE COAST OF SOUTH AMERICA TO THE DATE LINE. THREE OF THE NINO INDICES WERE GENERALLY COOLER THAN -0.5 DEG C THROUGHOUT AUGUST, WITH ONLY NINO 4 REMAINING NEAR AVERAGE. THE UPPER-OCEAN HEAT CONTENT (AVERAGE TEMPERATURES IN THE UPPER 300 M OF THE OCEAN) IN THE CENTRAL AND EAST-CENTRAL EQUATORIAL PACIFIC CONTINUED TO BE BELOW AVERAGE, WITH TEMPERATURES AT THERMOCLINE DEPTH RANGING FROM 1 TO 3 DEG C BELOW AVERAGE. WHILE NOT AS PRONOUNCED AS DURING PREVIOUS MONTHS... THE LOW-LEVEL EASTERLY WINDS WERE STRONGER THAN AVERAGE IN THE WEST-CENTRAL EQUATORIAL PACIFIC, CONVECTION WAS SUPPRESSED THROUGHOUT THE CENTRAL AND EASTERN EQUATORIAL PACIFIC... AND A WEAK AREA OF ENHANCED CONVECTION COVERED PARTS OF INDONESIA AND THE FAR WESTERN PACIFIC. COLLECTIVELY, THE OCEANIC AND ATMOSPHERIC CONDITIONS ARE CONSISTENT WITH DEVELOPING LA NINA CONDITIONS. HOWEVER THE DEVELOPMENT OF LA NINA CONDITIONS IS NOT EXPECTED TO EXERT MUCH INFLUENCE ON CLIMATE ANOMALIES OVER THE U.S. DURING SEPTEMBER. THE TRADITIONAL STATISTICAL TOOLS... SMLR... CCA... AND OCN ALL FAVOR ABOVE AVERAGE TEMPERATURES IN PARTS OF THE WEST... WITH THE OCN SIGNAL THE STRONGEST IN THE SOUTHWEST. THE SMLR AND CCA HAVE WEAKER INDICATIONS OF ABOVE NORMAL TEMPERATURES MAINLY IN CALIFORNIA. ALL 3 TOOLS ALSO SHOW SOME INDICATION FOR ABOVE AVERAGE TEMPERATURES OVER SOUTHERN FLORIDA. SHORT-RANGE GUIDANCE INDICATES ABOVE NORMAL TEMPERATURES ACROSS PARTS OF THE WEST DURING THE FIRST TEN DAYS OF THE MONTH... AND ALSO INDICATES ABOVE NORMAL TEMPERATURES IN A MORE EXPANSIVE REGION OF THE SOUTHEAST. THE PROBABILITY OF ABOVE NORMAL TEMPERATURES HAS BEEN INCREASED THROUGHOUT PARTS OF THE SOUTHEAST DUE TO THE SHORT RANGE INDICATIONS AND ALSO DUE TO INDICATIONS FROM SOIL MOISTURE CONCERNS. THE CFS AND CAS CONTINUE TO HAVE INDICATIONS FOR BELOW AVERAGE TEMPERATURES IN THE SOUTH-CENTRAL PLAINS IN THE REGION THAT CONTINUES TO HAVE WELL ABOVE NORMAL SOIL MOISTURE CONDITIONS. FORECASTS FOR THE 6-10 AND 8-14 DAY PERIODS ALSO HAVE ENHANCED PROBABILITIES OF BELOW NORMAL TEMPERATURES IN THIS REGION. THEREFORE... HAVE ELECTED TO SHOW AN REGION OF ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES CENTERED IN OKLAHOMA. GENERALLY MIXED OR STATISTICALLY INSIGNIFICANT SIGNALS WERE FOUND OVER THE REST OF THE CONUS AND ALASKA. SMLR... CCA... OCN... CFS... AND CAS ALL INDICATE BELOW MEDIAN PRECIPITATION FOR SOME PARTS OF THE WEST. EXTENDED RANGE GUIDANCE ALSO FAVORS DRIER THAN MEDIAN CONDITIONS OVER LARGE PARTS OF THE WEST DURING THE WEEK 2 PERIOD. AN AREA OF ENHANCED PROBABILITY OF BELOW MEDIAN PRECIPITATION IS PREDICTED FOR PARTS OF THE WEST FROM SOUTHERN IDAHO AND OREGON SOUTHWARD TO CENTRAL ARIZONA AND NEW MEXICO... WITH THE LARGEST PROBABILITIES IN PARTS OF NEVADA... UTAH AND ARIZONA. AN ENHANCED CHANCE OF ABOVE MEDIAN PRECIPITATION IS ALSO PREDICTED ALONG THE GULF AND SOUTH ATLANTIC COASTS FROM SOUTHERN TEXAS TO SOUTHERN VIRGINIA. MUCH OF THE REGION ALONG FOR GULF COAST FROM SOUTH TEXAS TO FLORIDA AND GEORGIA IS ALSO ANTICIPATED TO RECEIVE LARGE RAINFALL TOTALS DURING THE EARLY PART OF THE MONTH. THIS FORECAST IS ALSO CONSISTENT WITH NOAA'S FORECAST FOR AN ACTIVE HURRICANE SEASON. HISTORICALLY SIMILAR ACTIVE SEASONS HAVE TYPICALLY PRODUCED 2-4 HURRICANE STRIKES IN THE CONTINENTAL UNITED STATES. FORECASTER: MIKE HALPERT NOTES: AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL PROBABILITIES) ARE NOW LABELED AS EC (EQUAL CHANCES). THE NEXT MONTHLY OUTLOOK...FOR OCTOBER 2007...WILL BE ISSUED ON THU SEP 20 2007 THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD. $$