PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THURSDAY MAY 15 2014 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS THE MAIN FACTORS THAT USUALLY INFLUENCE THE SEASONAL CLIMATE OUTLOOK INCLUDE: 1) EL NINO AND LA NINA - WHICH TOGETHER COMPRISE EL NINO/SOUTHERN OSCILLATION OR ENSO. IMPACTS OF THESE EVENTS ARE SUMMARIZED BY SEPARATING 3-MONTH OBSERVATIONS FROM 3 OR MORE DECADES INTO EL NINO, NEUTRAL, AND LA NINA SETS, AVERAGING EACH SEPARATELY, AND THEN COMPUTING ANOMALIES. THESE ARE CALLED "ENSO COMPOSITES", WHICH ARE USED AT TIMES TO SUBJECTIVELY MODIFY THE FORECAST. 2) TRENDS - APPROXIMATED BY THE OCN TOOL AS 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 1981-2010). 3) THE TROPICAL 30-60 DAY OSCILLATION - SOMETIMES CALLED MADDEN JULIAN OSCILLATION (MJO) - AFFECTS CLIMATE VARIABILITY WITHIN SEASONS. 4) THE NORTH ATLANTIC OSCILLATION (NAO) AND THE PACIFIC NORTH AMERICAN (PNA) PATTERNS - WHICH AFFECT THE TEMPERATURE ANOMALY PATTERN ESPECIALLY DURING THE COLD SEASONS. THESE PHENOMENA ARE CONSIDERED LESS PREDICTABLE ON A SEASONAL TIMESCALE THAN ENSO. 5) THE PACIFIC DECADAL OSCILLATION (PDO) - AN ENSO-LIKE PATTERN OF CLIMATE VARIABILITY AFFECTING THE TROPICS AND THE NORTH PACIFIC AND NORTH AMERICAN REGIONS, BUT WHICH VARIES ON A MUCH LONGER TIME-SCALE THAN ENSO. 6) PERSISTENTLY DRY OR WET SOILS IN THE SPRING AND SUMMER AND SNOW AND ICE COVER ANOMALIES IN THE WINTER. THESE FACTORS TEND TO PERSIST FOR LONG PERIODS AND ACT AS A KIND OF MEMORY IN THE CLIMATE SYSTEM. 7) STATISTICAL FORECAST TOOLS - CANONICAL CORRELATION ANALYSIS (CCA), SCREENING MULTIPLE LINEAR REGRESSION (SMLR), CONSTRUCTED ANALOGUE (CA) AND ENSEMBLE CCA (ECCA). 8) DYNAMICAL FORECAST MODELS - INCLUDING THE NCEP CLIMATE FORECAST SYSTEM (CFS). AN EXPERIMENTAL MODEL FORECAST SYSTEM, THE NATIONAL MULTI-MODEL ENSEMBLE, COMPRISED OF SEVERAL MODELS AND DESIGNATED NMME, MAY ALSO BE USED EXPERIMENTALLY AND SUBJECTIVELY UNTIL IT IS INCLUDED INTO THE CONSOLIDATION. AN INTERNATIONAL MODEL ENSEMBLE DESIGNATED IMME IS ALSO AVAILABLE. 9) CONSOLIDATION (CON) - AN OBJECTIVE, SKILL-WEIGHTED COMBINATION OF THE OCN, CCA, SMLR, ECCA, AND CFS FORECASTS IS USED AS A FIRST GUESS IN PREPARING THE FORECAST MAPS. THIS TECHNIQUE MAKES OPTIMUM USE OF THE KNOWN SKILL OF FORECAST TOOLS. CURRENT ATMOSPHERIC AND OCEANIC OBSERVATIONS SUGGEST A TRANSITION FROM ENSO-NEUTRAL TO EL NINO CONDITIONS IS UNDERWAY. STATISTICAL AND DYNAMICAL PREDICTION MODELS HAVE BEEN FORECASTING A TRANSITION TO EL NINO CONDITIONS BY THE SUMMER OF 2014 FOR THE PAST SEVERAL MONTHS. THE MOST RECENT SEA SURFACE TEMPERATURES (SSTS) ARE MORE THAN 0.5 DEGREES CELSIUS ABOVE NORMAL ALONG THE EQUATOR THROUGHOUT MOST OF THE CENTRAL AND EASTERN PACIFIC OCEAN. ABOVE NORMAL SSTS HAVE RECENTLY EMERGED NEAR THE EQUATOR ALONG THE SOUTH AMERICAN COAST. ATMOSPHERIC INDICATORS OF DEVELOPING EL NINO CONDITIONS ARE ALSO INCREASINGLY EVIDENT IN THE OBSERVATIONS, SUCH AS UNUSUALLY ACTIVE CONVECTION NEAR THE EQUATOR OVER THE CENTRAL PACIFIC, AND THE WEAKENING OF THE TRADE WINDS. EL NINO CONDITIONS ARE EXPECTED TO BE IN PLACE BY LATE SUMMER OR EARLY FALL, HOWEVER, THERE IS STILL CONSIDERABLE DISAGREEMENT AMONG PREDICTIONS OF THE STRENGTH AND DURATION OF THE EVENT. THE TEMPERATURE OUTLOOK FOR JUNE-JULY-AUGUST (JJA) 2014 INDICATES ELEVATED ODDS OF ABOVE-NORMAL TEMPERATURES IN MOST AREAS WEST OF THE ROCKY MOUNTAINS. ABOVE-NORMAL TEMPERATURES ARE FAVORED FROM PARTS OF THE SOUTHERN ROCKIES TO TEXAS AND THE SOUTHERN GREAT PLAINS. ELEVATED CHANCES FOR ABOVE-NORMAL TEMPERATURES IN THE EASTERN PART OF THE NATION ARE RESTRICTED TO STATES ALONG THE GULF COAST AND ALONG THE ATLANTIC SEABOARD FROM FLORIDA TO NEW ENGLAND. BELOW-NORMAL TEMPERATURES ARE FAVORED FROM THE NORTHERN ROCKIES TO THE UPPER GREAT LAKES. THE CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE ENHANCED FOR ALASKA. THE JJA 2014 PRECIPITATION OUTLOOK CALLS FOR ENHANCED PROBABILITIES OF BELOW-MEDIAN PRECIPITATION ALONG THE WESTERN COAST OF THE GULF OF MEXICO. THERE IS A FAIRLY LARGE REGION OF ELEVATED CHANCES FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR MUCH OF THE INTERIOR WEST, FROM PARTS OF THE SOUTHERN ROCKIES NORTHWARD TO IDAHO AND SOUTHERN MONTANA. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR SOUTHEAST ALASKA. IN AREAS WHERE THE LIKELIHOODS OF SEASONAL MEAN TEMPERATURES AND SEASONAL ACCUMULATED PRECIPITATION AMOUNTS ARE SIMILAR TO CLIMATOLOGICAL PROBABILITIES, EQUAL CHANCES (EC) IS SHOWN. THE TEMPERATURE AND PRECIPITATION OUTLOOKS FOR SON 2014 - MAM 2015 ARE HEAVILY INFLUENCED BY THE TYPICAL CLIMATIC ANOMALIES ASSOCIATED WITH EL NINO. IT IS IMPORTANT TO NOTE THAT THE CHANCES OF AN EL NINO OF SUFFICIENT STRENGTH TO RELIABLY INFLUENCE THE TEMPERATURES AND PRECIPITATION OVER THE U.S. APPEAR AT THIS TIME TO BE AROUND OR JUST UNDER 70%. THE EVOLUTION OF THE ENSO CONDITIONS IN THE COMING MONTHS IS CRITICAL TO THE CLIMATE ANOMALIES THIS FALL AND WINTER. THIS MONTH'S CLIMATE OUTLOOK AT LONGER LEADS REFLECTS THE ANOMALIES ASSOCIATED WITH EL NINO, BUT WITH REDUCED CONFIDENCE TO REFLECT UNCERTAINTY IN THE ENSO STATE. IF THE EXPECTED ENSO STATE CHANGES IN THE NEXT FEW MONTH, SUBSTANTIAL REVISIONS MAY BE MADE ON FUTURE OUTLOOKS FOR WINTER 2014-2015. BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOKS 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 ATMOSPHERE AND OCEANIC CONDITIONS IN THE PACIFIC BASIN INDICATE THAT A TRANSITION TO EL NINO CONDITIONS IS UNDERWAY. THE LATEST WEEKLY OBSERVATIONS SHOW SST ANOMALIES OF +0.5 DEGREES C ALONG THE EQUATOR THROUGHOUT THE EASTERN AND CENTRAL PACIFIC, WITH ANOMALIES EXCEEDING +1.0 C IN PLACES. POSITIVE SST ANOMALIES HAVE RECENTLY APPEARED NEAR THE EQUATOR ALONG THE SOUTH AMERICAN COAST. STRONGLY POSITIVE SUB-SURFACE OCEAN TEMPERATURE ANOMALIES RESULTING FROM A KELVIN WAVE HAVE PUSHED THE SUB-SURFACE OCEAN HEAT CONTENT OF THE UPPER 300 M IN THE EAST-CENTRAL EQUATORIAL PACIFIC WELL ABOVE NORMAL. HEAT CONTENT HAS DIMINISHED SOMEWHAT DURING THE LAST 30-DAYS AFTER THE PASSING OF THE DOWNWELLING PHASE OF THE KELVIN WAVE, BUT REMAINS AT AROUND 1.2 C ABOVE NORMAL IN EARLY MAY. ATMOSPHERIC CONDITIONS OVER THE EQUATORIAL PACIFIC ARE ALSO BEGINNING TO REFLECT THE POSSIBLE EMERGENCE OF A WARM ENSO EVENT WITH WEAK WESTERLY WIND ANOMALIES AT LOW LEVELS, AND SLIGHTLY ENHANCED CONVECTION OVER THE EAST-CENTRAL PORTION OF THE OCEAN BASIN. MEAN ANOMALIES AT THIS POINT ARE STILL FAIRLY WEAK, AND NINO 3.4 SST ANOMALIES HAVE ONLY RECENTLY REACHED THE +0.5 DEGREES C THRESHOLD INDICATIVE OF EL NINO CONDITIONS, SO THE CURRENT ENSO STATE IS STILL CLASSIFIED AS NEUTRAL. HOWEVER, IF CURRENT CONDITIONS PERSIST, A TRANSITION TO EL NINO CONDITIONS IS LIKELY IN THE NEXT FEW MONTHS. PROGNOSTIC DISCUSSION OF SST FORECASTS MOST STATISTICAL AND DYNAMICAL MODELS CONTINUE TO SUGGEST THAT EL NINO CONDITIONS WILL EMERGE IN THE NEXT FEW MONTHS. THE CFSV2 PREDICTS NINO 3.4 SST ANOMALIES TO INCREASE TO AROUND +1.0 C BY LATE SUMMER. MOST STATISTICAL MODELS PREDICT SSTS ONLY SLIGHTLY ABOVE THE +0.5 DEGREE C ANOMALY THRESHOLD ASSOCIATED WITH EL NINO CONDITIONS. THE CPC SST CONSOLIDATION FORECAST PREDICTS THE SST ANOMALY FOR NINO 3.4 TO BE NEARLY IDENTICAL TO ITS FORECAST OF ONE MONTH AGO AND HAS ANOMALIES INCREASING TO JUST UNDER 1.0 C BY THE FALL. THE LATEST ENSEMBLE MEAN FORECASTS FROM THE IMME AND NMME ALSO PREDICT SST ANOMALIES INCREASING FROM +0.5 C IN JUNE TO NEAR +1.0 BY OCTOBER. THERE IS STILL UNCERTAINTY IN THE PREDICTION OF THE STRENGTH OF THE POSSIBLE EVENT. THE CONTINUED WEAK FORECAST FROM STATISTICAL MODELS SUGGEST ABOUT A 70% CHANCE OF EL NINO DEVELOPING BY LATE SUMMER. THE COMBINATION OF STATISTICAL AND DYNAMICAL SST PREDICTION METHODS SUGGESTS A BORDERLINE MODERATE EVENT, ALTHOUGH THE POSSIBILITY OF A STRONG EVENT, OR A RETURN TO ENSO NEUTRAL CONDITIONS, THOUGH LESS LIKELY, CANNOT BE RULED OUT AT THIS POINT. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE TEMPERATURE AND PRECIPITATION OUTLOOKS WERE MADE CONSIDERING ENSO CONDITIONS TO BE A FACTOR THIS SUMMER. GUIDANCE FROM THE CFSV2 AS WELL AS THE NMME AND IMME AND THEIR ASSOCIATED COMPONENTS CONTRIBUTED TO THE OUTLOOKS FROM JJA THROUGH SON 2014, ESPECIALLY WHERE THEIR ANOMALIES AGREED WITH COMPOSITES FROM DEVELOPING EL NINOS. THE OUTLOOKS FROM OND 2014 THROUGH FMA 2015 WERE PRIMARILY DETERMINED FROM EL NINO COMPOSITES, WITH PROBABILITIES REDUCED FROM THOSE ASSOCIATED WITH A MODERATE ENSO EVENT TO REFLECT THAT EL NINO CONDITIONS HAVE NOT YET FULLY DEVELOPED, AND UNCERTAINTY IN THE ENSO FORECAST. THE MODEL CONSENSUS FOR THE STRENGTH OF EL NINO IS NO STRONGER THAN IT WAS A MONTH AGO, SUGGESTING A WEAK OR MODERATE EVENT LATE IN THE YEAR IS STILL THE BEST ESTIMATE OF ITS INTENSITY AT THIS TIME. THE EL NINO COMPOSITES WERE BLENDED WITH THE BACKGROUND CLIMATE SIGNAL FROM RECENT TRENDS IN OUTLOOKS FROM MAM THROUGH AMJ 2015. FOR MJJ 2015 AND BEYOND, THE OUTLOOKS MAINLY REFLECT LONG TERM TRENDS AS ESTIMATED BY OCN AND THE CONSOLIDATION OF STATISTICAL TOOLS. PROGNOSTIC DISCUSSION OF OUTLOOKS - JJA 2014 TO JJA 2015 TEMPERATURE THE JJA AND JAS 2014 TEMPERATURE OUTLOOK INDICATES ELEVATED PROBABILITIES OF ABOVE- NORMAL SEASONAL MEAN TEMPERATURES FOR ALL OF ALASKA, AND ALSO MOST OF THE AREA TO THE WEST OF THE ROCKY MOUNTAINS IN THE CONUS. ABOVE-NORMAL TEMPERATURES ARE FAVORED IN THE SOUTHERN ROCKIES, PARTS OF THE SOUTHERN GREAT PLAINS AND IN TEXAS. THESE SIGNALS ARE SUPPORTED BY A BROAD RANGE OF TOOLS AND DYNAMICAL CLIMATE MODELS. THE PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE REDUCED TO NEAR CLIMATOLOGICAL VALUES ALONG THE WESTERN COAST OF THE GULF OF MEXICO DUE TO EXPECTED BELOW-NORMAL COASTAL SSTS IN JUNE. TRENDS FAVOR ABOVE-NORMAL TEMPERATURES IN PARTS OF THE EASTERN CONUS, HOWEVER, COMPOSITES SUGGEST NEAR- TO BELOW-NORMAL TEMPERATURES IN MUCH OF THE EASTERN AND CENTRAL CONUS DURING DEVELOPING EL NINO EVENTS. THE COMPOSITES RESEMBLE THE IMME TEMPERATURE ANOMALY FORECAST, WITH ELEVATED CHANCES OF BELOW-NORMAL TEMPERATURES FROM THE NORTHERN ROCKIES TO THE UPPER GREAT LAKES. ELEVATED CHANCES OF ABOVE-NORMAL TEMPERATURES DUE TO TRENDS ARE FAVORED IN THE EAST ONLY NEAR THE GULF OF MEXICO AND ATLANTIC COASTS. THE NMME AND IMME BOTH FAVOR ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR THE SOUTHERN AND CENTRAL ROCKY MOUNTAINS, WHICH IS EXPECTED TO HAVE A MODERATING EFFECT ON TEMPERATURES, REDUCING THE CHANCES OF ABOVE-NORMAL TEMPERATURES TO NEAR CLIMATOLOGICAL VALUES IN SPITE OF RECENT TRENDS FAVORING WARM CONDITIONS. OUTLOOKS FROM SON 2014 THROUGH NDJ 2014-2015 SHOW A SLOW TRANSITION TO THE EXPECTED WINTERTIME TEMPERATURE PATTERN ASSOCIATED WITH EL NINO. ABOVE-NORMAL TEMPERATURES ARE GENERALLY FAVORED IN THE NORTHERN CONUS AND ALASKA, WITH INCREASING ODDS OF BELOW-NORMAL TEMPERATURES IN THE SOUTHERN CONUS. BECAUSE THE TENDENCY FOR BELOW-NORMAL TEMPERATURES IN THE SOUTHERN CONUS CONTRADICTS RECENT TRENDS IN THE FALL AND EARLY WINTER, A FORECAST OF "EQUAL CHANCES" WAS ISSUED FOR BROAD AREAS OF THE SOUTHERN CONUS. THE TEMPERATURE OUTLOOKS FOR DJF 2014-2015 THROUGH FMA 2015 REFLECT TEMPERATURE PATTERNS ASSOCIATED WITH EL NINO, WITH SLIGHT ELEVATION OF THE CHANCES OF BELOW-NORMAL TEMPERATURES IN THE SOUTHERN CONUS IN THESE SEASONS, AND SLIGHTLY ELEVATED CHANCES FOR ABOVE-NORMAL TEMPERATURES IN PARTS OF THE NORTHERN CONUS AND MOST OF ALASKA. THE OUTLOOKS FROM MAM TO AMJ 2015 SHOW A TRANSITION FROM TEMPERATURE PATTERNS INFLUENCED BY EL NINO TO THOSE FAVORED BY RECENT TRENDS. IN AREAS WITHOUT SUBSTANTIAL AND RELIABLE CLIMATE SIGNALS, EQUAL CHANCES OF BELOW-, NEAR- AND ABOVE-NORMAL SEASONAL MEAN TEMPERATURES ARE INDICATED. PRECIPITATION THE JJA 2014 PRECIPITATION OUTLOOK INDICATES ENHANCED PROBABILITIES OF BELOW-MEDIAN SEASONAL ACCUMULATED PRECIPITATION FOR THE ALASKA PANHANDLE. THIS SIGNAL IS CONSISTENT WITH DEVELOPING EL NINO CONDITIONS AND IS WEAKLY SUPPORTED BY THE NMME. THERE ARE FAIRLY STRONG AND CONSISTENT INDICATIONS FROM MOST MODELS RUN AS PART OF THE NMME AND IMME FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS THROUGHOUT MUCH OF THE SOUTHWEST, SOUTHERN AND CENTRAL ROCKY MOUNTAINS AND THE INTERMOUNTAIN WEST FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS. THE MODELS HAVE CONSISTENTLY POINTED TO THIS POSSIBILITY FOR THE PAST FEW MONTHS, AND CONSIDERING THAT THE MODEL FORECAST FOR DEVELOPING EL NINO CONDITIONS APPEARS ON TRACK, THE CHANCES FOR ABOVE-MEDIAN PRECIPITATION ARE ELEVATED FOR MANY PARTS OF THE WESTERN CONUS. COMPOSITES BASED ON SUMMERTIME EL NINO CONDITIONS TEND TO CONTRADICT THE NMME AND IMME IN THAT THEY GENERALLY SUPPORT A WEAK SOUTHWEST MONSOON, AT LEAST IN THE EARLY PART OF THE SUMMER. THIS LEADS TO GREATER UNCERTAINTY IN THE PRECIPITATION FORECAST ALONG THE U.S. - MEXICAN BORDER. ABOVE-NORMAL SSTS IN THE PACIFIC OFF THE CALIFORNIA AND MEXICAN COASTS DURING EL NINO FALLS PROVIDE AN ADDITIONAL MOISTURE SOURCE FOR PARTS OF THE DESERT SOUTHWEST AND SOUTHERN CALIFORNIA, ELEVATING CHANCES FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS. THIS FORECAST IS ALSO SUPPORTED BY THE NMME AND IMME. AS SEASONS PROGRESS INTO WINTER THE OUTLOOKS REFLECT THE PRECIPITATION PATTERN ASSOCIATED WITH EL NINO EVENTS, WITH ABOVE-MEDIAN PRECIPITATION AMOUNTS FAVORED THROUGHOUT MUCH OF THE SOUTHERN CONUS IN ASSOCIATION WITH AN EXPECTED ENERGIZED MEAN SOUTHERN JET STREAM, AND A TENDENCY FOR BELOW-MEDIAN AMOUNTS NEAR THE OHIO RIVER VALLEY AND ALSO IN PARTS OF THE NORTHERN ROCKIES. AT THIS POINT PROBABILITIES ARE ONLY MARGINALLY DIFFERENT FROM CLIMATOLOGICAL VALUES IN MOST AREAS DUE TO UNCERTAINTIES IN THE EVENTUAL STRENGTH OF EL NINO. THE PRECIPITATION OUTLOOK FOR MAM 2015 AND BEYOND SHOW EQUAL CHANCES FOR BELOW-, NEAR- AND ABOVE-MEDIAN SEASONAL ACCUMULATED PRECIPITATION THROUGHOUT THE CONUS AND ALASKA. STATISTICAL MODELS SHOW THE NINO 3.4 SST'S WEAKENING TO NEAR NORMAL BY LATE SPRING 2015, LEAVING LITTLE PREDICTABLE SIGNAL FOR PRECIPITATION ANOMALIES. FORECASTER: DAVID UNGER THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING THE WORLD METEROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3 COMPLETE DECADES AS THE CLIMATIC REFERENCE PERIOD. THE PROBABILITY ANOMALIES FOR TEMPERATURE AND PRECIPITATION BASED ON THESE NEW NORMALS BETTER REPRESENT SHORTER TERM CLIMATIC ANOMALIES THAN THE FORECASTS BASED ON OLDER NORMALS. FOR A DESCRIPTION OF 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 FORMATION OF 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 JUN 19 2014 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$