PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT MON MAY 31 2010 30-DAY OUTLOOK DISCUSSION FOR JUNE 2010 SEA SURFACE TEMPERATURE (SST) ANOMALIES NEAR THE EQUATOR IN THE EAST CENTRAL PACIFIC OCEAN DECREASED IN THE PAST WEEK, CONTINUING THE TREND IN SSTS OBSERVED IN THE PRIOR FEW WEEKS. SSTS ARE NOW BELOW NORMAL ALONG THE EQUATOR FROM THE SOUTH AMERICAN COAST TO ABOUT 170W LONGITUDE. EQUATORIAL SSTS ARE NOW MORE THAN .5 DEGREES C BELOW NORMAL THROUGHOUT MUCH OF THE EASTERN PACIFIC, WITH ANOMALIES MORE THAN -1.0 C IN PLACES. THIS IS CONSISTENT WITH THE SST FORECASTS FROM THE CFS AND OTHER TOOLS ISSUED EARLIER IN THE MONTH. A CONSOLIDATION FORECAST BASED THE CFS AND THREE STATISTICAL MODELS SUGGESTS THAT SSTS IN THE NINO 3.4 REGION (BETWEEN 5N AND 5S, 170W AND 120W) WILL REMAIN BELOW NORMAL THROUGH THE END OF JUNE AND BEYOND. CURRENT ATMOSPHERIC CONDITIONS ARE CONSISTENT WITH THE END OF LAST WINTER'S EL NINO. CONVECTION IN THE CENTRAL PACIFIC OCEAN, NORMALLY ASSOCIATED WITH EL NINO, WEAKENED CONSIDERABLY IN THE PAST MONTH OR SO. THE LOW LEVEL EQUATORIAL TRADE WINDS ARE NEAR-AVERAGE AND WESTERLY WIND ANOMALIES ARE OBSERVED AT UPPER LEVELS. THE UPDATED OUTLOOK FOR JUNE 2010 IS BASED PRIMARILY ON THE EXPECTED WEATHER CONDITIONS IN THE FIRST TWO WEEKS OF THE MONTH ACCORDING TO SHORT AND EXTENDED RANGE FORECASTS FROM THE GFS, AND ALSO ON 30-DAY PREDICTIONS FROM THE CFS. THE FORECAST IS MODIFIED BY LONGER TERM CLIMATIC SIGNALS, MAINLY BASED ON LOCAL SOIL MOISTURE CONDITIONS, THE INFLUENCE OF LOCAL SSTS ON TEMPERATURES ALONG SOME COASTAL AREAS, AND LONG TERM TEMPERATURE TRENDS. THERE IS GOOD MODEL AGREEMENT ON A MEAN UPPER LEVEL RIDGE LOCATED OVER THE WEST-CENTRAL U.S. IN THE FIRST HALF OF THE MONTH. THIS FAVORES ABOVE NORMAL TEMPERATURES FROM THE SOUTHWEST EASTWARD TO AT LEAST THE CENTRAL GREAT PLAINS. THE PERSISTENT UPPER LEVEL CIRCULATION EXPECTED IN THE FIRST HALF OF JUNE IS MORE THAN ENOUGH TO OFFSET THE WEAK SIGNALS FOR BELOW NORMAL TEMPERATURES BASED ON SOIL MOISTURE INDICATED ON THE JUNE OUTLOOK ISSUED IN MID-MAY. AS A RESULT, THE TEMPERATURE FORECAST FOR THE SOUTHERN GREAT PLAINS HAS BEEN SUBSTANTIALLY REVISED AND NOW INDICATES ELEVATED CHANCES OF ABOVE NORMAL TEMPERATURES FOR TEXAS AND THE SOUTHERN GREAT PLAINS. ABOVE NORMAL TEMPERATURES IN EARLY JUNE ARE EXPECTED IN THE SOUTHWESTERN CONUS AND THE SOUTHERN GREAT BASIN, AND ALSO IN INTERIOR ALASKA, DUE TO THE PREDICTED UPPER LEVEL CIRCULATION IN THE FIRST HALF OF THE MONTH. THIS ENHANCES THE PROBABILITY FOR ABOVE NORMAL TEMPERATURES DUE TO TRENDS THAT WERE INDICATED IN THE JUNE OUTLOOK ISSUED EARLIER IN THE MONTH. COASTAL SSTS OFF OF SOUTHWESTERN ALASKA REMAIN BELOW NORMAL, ENHANCING THE CHANCES OF BELOW NORMAL MEAN AIR TEMPERATURES FOR JUNE IN ADJACENT COASTAL LAND AREAS AND THE ALEUTIANS. THERE IS SOME SUGGESTION BY THE CFS MONTHLY MEAN 200 HPA AND 700 HPA HEIGHT FORECAST OF AN ENHANCED STORM TRACK OVER THE PACIFIC NORTHWEST FOR THE MONTH OF JUNE. THIS ELEVATES THE CHANCES OF BELOW NORMAL TEMPERATURES FROM THE PACIFIC NORTHWEST TO THE NORTHERN ROCKIES. THIS AREA IS EXTENDED SLIGHTLY EASTWARD TO THE NORTHERN GREAT PLAINS DUE TO ABOVE AVERAGE SOIL MOISTURE IN THE REGION IN LATE MAY. INITIALLY DRY CONDITIONS RELATED TO THE EXPECTED UPPER LEVEL CIRCULATION IN EARLY JUNE REQUIRES REMOVING THE ENHANCED CHANCES FOR ABOVE MEDIAN PRECIPITATION INDICATED FOR PARTS OF TEXAS FROM THE OUTLOOK ISSUED IN MID-MAY. FAVORABLE SOIL MOISTURE CONDITIONS COMBINE WITH INDICATIONS FOR ABOVE MEDIAN PRECIPITATION AMOUNTS FROM WEATHER PREDICTION MODELS IN EARLY JUNE TO ENHANCE THE CHANCES FOR ABOVE MEDIAN PRECIPITATION AMOUNTS FROM PARTS OF OKLAHOMA TO THE OHIO VALLEY. LATE SEASON PRECIPITATION EXPECTED IN THE FIRST WEEK THE MONTH IN PARTS OF THE PACIFIC NORTHWEST, EXTENDING INLAND TO THE THE NORTHERN ROCKY MOUNTAINS, ENHANCES THE CHANCE FOR ABOVE MEDIAN JUNE MONTHLY TOTALS IN THOSE AREAS. FORECASTER: DAVID UNGER NOTES: AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL PROBABILITIES) ARE NOW LABELED AS EC (EQUAL CHANCES). THE NEXT MONTHLY OUTLOOK...FOR JULY 2010...WILL BE ISSUED ON THU JUN 17 2010 THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD. $$