PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830 AM EDT THU JUL 20 2006 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS THE MAIN FACTORS WHICH USUALLY INFLUENCE SEASONAL CLIMATE INCLUDE 1) EL NINO AND LA NINA - WHICH TOGETHER MAKE UP EL NINO/SOUTHERN OSCILLATION OR ENSO - 2) TRENDS - APPROXIMATED BY THE DIFFERENCE BETWEEN THE MOST RECENT 10-YEAR MEAN OF TEMPERATURE OR 15-YEAR MEAN OF PRECIPITATION FOR A GIVEN LOCATION AND TIME OF YEAR AND THE 30-YEAR CLIMATOLOGY PERIOD (CURRENTLY 1971-2000) - 3) TROPICAL 30-60-DAY OSCILLATION- WHICH MAY AFFECT CLIMATE VARIABILITY WITHIN A SEASON - 4) THE NORTH ATLANTIC OSCILLATION - OR NAO - AND THE PNA - THE PACIFIC NORTH AMERICAN PATTERN 5) PERSISTENTLY DRY OR WET SOILS IN THE SUMMER AND SNOW AND ICE COVER ANOMALIES IN THE WINTER. 6) AN OBJECTIVE CONSOLIDATION (CALLED CON IN THE TEXT) OF THE OCN, CCA, SMLR AND CFS FORECASTS IS USED AS A FIRST-GUESS IN PREPARING THE FORECAST MAPS. SSTS IN MUCH OF THE CENTRAL AND EASTERN EQUATORIAL PACIFIC ARE CURRENTLY CLOSE TO NORMAL... INDICATING NEUTRAL ENSO CONDITIONS. MOST PREDICTION TOOLS INDICATE THAT SST ANOMALIES WILL BE SLIGHTLY POSITIVE BUT NO MORE THAN 0.5 CENTIGRADE IN THE ENSO-SENSITIVE REGIONS OF THE PACIFIC... SUGGESTING THAT CLIMATE IMPACTS RELATED TO EL NINO OR LA NINA IN THIS SERIES OF OUTLOOKS WILL BE NEGLIGABLE. THE TEMPERATURE OUTLOOK FOR AUG-SEP-OCTOBER (ASO) 2006 CALLS FOR WARMER THAN NORMAL CONDITIONS OVER MOST OF THE U.S. WEST OF THE MISSISSIPPI RIVER. ABOVE NORMAL TEMPERATURES ARE ALSO EXPECTED IN NEW ENGLAND AND THE FLORIDA PENINSULA. ELSEWHERE THERE ARE EQUAL CHANCES OF WARMER-THAN ... COOLER-THAN... OR NEAR-NORMAL TEMPERATURES DURING ASO. TEMPERATURE ANOMALIES ARE MAINLY DUE TO TRENDS... ALTHOUGH DRY SOIL MOISTURE CONDITIONS IN THE SOUTHERN PLAINS AND INTERIOR TEXAS ALSO HELP INCREASE THE CHANCES FOR ABOVE NORMAL TEMPERATURES IN THOSE REGIONS. THE PRECIPITATION OUTLOOK FOR AUG-SEP-OCT (ASO) 2006 CALLS FOR BELOW MEDIAN PRECIPITATION IN PARTS OF NORTHERN CALIFORNIA AND NEVADA... DUE TO LONG TERM TRENDS IN THE REGION. THE CHANCES FOR ABOVE MEDIAN PRECIPITATION ARE ENHANCED OVER FLORIDA AND PORTIONS OF THE SOUTHEASTERN U.S. DUE TO LONG TERM TRENDS AND THE EXPECTATION OF AN ACTIVE ATLANTIC HURRICANE SEASON... ALTHOUGH IT SHOULD BE EMPHASIZED THAT THIS PRECIPITATION OUTLOOK SHOULD NOT BE USED TO INFER CHANGES IN HURRICANE STRIKE PROBABILITIES. BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOK NOTE: FOR GRAPHICAL DISPLAYS OF THE FORECAST TOOLS DISCUSSED BELOW SEE: HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/TOOLS/BRIEFING CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS SSTS ALONG THE EQUATOR IN THE PACIFIC ARE MOSTLY WITHIN .5 DEG C OF NORMAL. THE SSTS IN THE NINO 3.4 REGION... A CRITICAL INDICATOR FOR THE ENSO STATE... CURRENTLY AVERAGE ABOUT .3 DEG C ABOVE NORMAL. BOTH THE LOW LEVEL AND UPPER LEVEL WINDS IN THE TROPICAL PACIFIC AVERAGED CLOSE TO NORMAL IN THE LAST MONTH OR SO. THESE INDICATORS SUGGEST THAT ENSO IS IN A NEUTRAL PHASE. CONVECTION PATTERNS IN THE EQUATORIAL PACIFIC APPEAR TO BE INFLUENCED BY VERY WEAK MADDEN-JULIAN OSCILLATION (MJO)ACTIVITY. THE HEAT CONTENT IN THE EQUATORIAL PACIFIC OCEAN HAS INCREASED MARKEDLY IN THE LAST FIVE MONTHS... AND IS NOW NOTICEABLY ABOVE THE LONG TERM AVERAGE. PROGNOSTIC DISCUSSION OF SST FORECASTS A CONSOLIDATION OF NCEP SST MODELS PREDICTS THAT NINO 3.4 SSTS WILL MOST LIKELY BE IN A RANGE AROUND .5 DEGREES C OR LESS ABOVE NORMAL. THERE IS MODERATE SPREAD AMONG MODEL SOLUTIONS FOR THE NEXT FEW MONTHS... INDICATING SOME UNCERTAINTY IN THE FORECAST. MODEL SPREAD DOES NOT SUBSTANTIALLY INCREASE THROUGH THE WINTER MONTHS. MODELS SUGGEST THAT THE CHANCES THAT THE NINO 3.4 SSTS WILL EXCEED THE 0.5 DEGREE C THRESHOLD FOR MINIMAL EL NINO RELATED IMPACTS PEAK AT AROUND 35 PERCENT IN OND 2006... DIMINISHING TO AROUND 25 PERCENT IN THE BOREAL WINTER AND INTO EARLY 2007. THE PREDICTED CHANCES FOR LA NINA CONDITION ARE NEGLIGIBLE. THUS NEUTRAL ENSO CONDITIONS ARE EXPECTED TO PREVAIL THROUGH ALL SEASONS COVERED BY THIS OUTLOOK. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE OUTLOOK FOR ASO 2006 THROUGH ASO 2007 IS BASED ON THE CFS... THE MULTI-MODEL ENSEMBLE FROM IRI... AND THE CDC-CCA RENDERING OF THE MOST LIKELY CONSENSUS FORECAST OF SEVERAL DYNAMICAL MODEL FORECASTS... AS WELL AS CCA... ECCA... SMLR... AND OCN. FORECASTS FROM JAS THROUGH DJF 2006 PRIMARILY REFLECT THE CONSOLIDATED TEMPERATURE AND PRECIPITATION PRODUCTS (A SKILL-WEIGHTED OBJECTIVE BLEND OF CFS... CCA... SMLR... AND OCN). THE OUTLOOKS FOR FMA 2007 THROUGH ASO 2007 ARE BASED LARGELY ON A CONSOLIDATION OF CCA... SMLR... AND OCN (CFS IS NOT AVAILABLE AFTER LEAD 6)... MAINLY LONG-TERM TRENDS. A STATISTICAL FORECAST TOOL BASED ON ANTECEDENT SOIL MOISTURE CONDITIONS (CAS) HAD SOME INFLUENCE ON THE OUTLOOK FOR ASO 2006. PROGNOSTIC DISCUSSION OF OUTLOOKS - ASO 2006 TO ASO 2007 TEMPERATURE: TEMPERATURE PROBABILITIES FOR ASO AND SON 2006 ARE SIMILAR TO THOSE ISSUED LAST MONTH WITH SLIGHT INCREASES IN AREAS WHERE WE FORECAST ABOVE NORMAL. FOR ASO WE EXTENDED WARMTH INTO THE OHIO VALLEY DUE TO THE CONSOLIDATION TOOL. IN THE NORTHWEST WE ELECTED EC BECAUSE CFS PREDICTS COLD WHERE OTHER TOOLS INDICATE WARMTH. THE OUTLOOKS FOR SON 2006 THROUGH JFM 2006-2007 REFLECT FORECASTS FROM OCN... CCA... SMLR... AND CFS... HOWEVER... WITH ENSO EXPECTED TO HAVE LITTLE INFLUENCE ON TEMPERATURES IN THIS SET OF OUTLOOKS... TEMPERATURE TRENDS DOMINATE THE PREDICTABLE SIGNALS FROM THESE TOOLS. THE OUTLOOKS FOR JFM 2007 AND BEYOND ARE ALMOST ENTIRELY A REFLECTION OF TEMPERATURE TRENDS. FOR ALL LEADS THERE ARE ELEVATED CHANCES FOR ABOVE NORMAL IN MUCH OF THE WEST. THE WARM SIGNAL IN THE EAST AT EARLY PROJECTIONS WEAKENS IN THE FALL TRANSITION SEASON BEFORE INCREASING AGAIN AS WINTER APPROACHES. TRENDS FOR ABOVE NORMAL TEMPERATURES BECOME STRONGEST IN LATE WINTER... WHEN THE CHANCES FOR ANMALOUS WARMTH BECOME ELEVATED THROUGHOUT THE CONUS. TEMPERATURE TRENDS IN THE EASTERN AND CENTRAL U.S. WEAKEN IN THE SPRING. AN AREA FAVORING ABOVE NORMAL TEMPERATURES DEVELOPS OVER THE SOUTHEASTERN STATES IN MJJ 2007 AND SPREADS NORTHWARD TO INCLUDE MOST OF THE EASTERN SEABOARD BY JJA 2007 BEFORE DIMINISHING AGAIN AS THE FALL TRANSITION SEASON APPROACHES. ABOVE NORMAL TEMPERATURES ARE FAVORED IN SOUTHERN AND WESTERN ALASKA IN MOST SEASONS EXCEPT FOR THE FALL. ABOVE NORMAL TEMPERATURES ARE FAVORED IN NORTHERN ALASKA IN THE WINTER AND SPRING SEASONS. PRECIPITATION: BELOW MEDIAN PRECIPITATION IS INDICATED FOR PARTS OF CALIFORNIA AND NEVADA IN ASO... DUE TO RECENT TRENDS. ABOVE MEDIAN PRECIPITATION FOR THE SOUTHEASTERN U.S. FOR ASO AND SON 2006 IS FROM LONG TERM TRENDS AND AN ANTICIPATED ACTIVE ATLANTIC HURRICANE SEASON. WE ADDED AN AREA OF BELOW MEDIAN PRECIPITATION IN THE OHIO VALLEY MAINLY IN SON DUE TO CCA WITH SOME REPRESENTATION ALREADY IN ASO AND INTO OND. WE ALSO ADDED AN AREA OF ABOVE MEDIAN PRECIPITATION DUE TO TRENDS IN THE PACIFIC NORTHWEST IN AMJ AND MJJ. THE REMAINING OUTLOOKS ARE LITTLE CHANGED FROM THOSE ISSUED FOR CORRESPONDING SEASONS LAST MONTH. OCN FAVORS ABOVE MEDIAN PRECIPITATION IN FLORIDA FOR JAS AND ASO 2007... AND FAVORS BELOW MEDIAN PRECIPITATION IN JAS 2007 IN PARTS OF THE PACIFIC NORTHWEST AND NORTHERN ROCKIES. NOTE - AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL PROBABILITIES) ARE NOW LABELED EC (EQUAL CHANCES). FORECASTER: HUUG VAN DEN DOOL STARTING WITH THE SEASONAL OUTLOOK RELEASED IN FEBRUARY, 2006, THE GLOSSARY OF TERMS WILL NO LONGER APPEAR WITH THIS MESSAGE. INSTEAD, TERMS THAT ARE IN THE GLOSSARY WILL BE LINKED TO THEIR DEFINITION. FOR A DESCRIPTION OF THE STANDARD FORECAST TOOLS - THEIR SKILL - AND THE FORECAST FORMAT PLEASE SEE OUR WEB PAGE AT HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/DISC.HTML (USE LOWER CASE LETTERS) INFORMATION ON THE FORMULATION AND SKILL OF THE CAS FORECASTS MAY BE FOUND AT: HTTP://WWW.CPC.NCEP.NOAA.GOV/SOILMST/FORECASTS.HTML (USE LOWERCASE LETTERS) NOTES - THESE CLIMATE OUTLOOKS ARE INTENDED FOR USE PRIOR TO THE START OF THEIR VALID PERIOD. WITHIN ANY GIVEN VALID PERIOD OBSERVATIONS AND SHORT AND MEDIUM RANGE FORECASTS SHOULD BE CONSULTED. THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE ISSUANCE OF THE NEW SET NEXT MONTH ON THU AUG 17 2006. 1971-2000 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 17, 2001 FORECAST RELEASE $$