90 Day Narrative

679 
FXUS05 KWBC 161231
PMD90D
PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EDT THU MAR 16 2017
SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS
THE APRIL-MAY-JUNE (AMJ) 2017 TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL 
TEMPERATURES FOR MUCH OF THE U.S. FOR THE CONTIGUOUS U.S., ABOVE-NORMAL 
SEASONAL MEAN TEMPERATURES ARE MOST LIKELY FOR AN AREA STRETCHING EASTWARD FROM 
THE SOUTHWEST TO MUCH OF THE CENTRAL AND EASTERN U.S. WITH THE GREATEST ODDS 
INDICATED FOR THE SOUTH-CENTRAL PLAINS AND EASTERN U.S. ABOVE-NORMAL 
TEMPERATURES ARE ALSO FAVORED FOR MUCH OF ALASKA.   
THE AMJ 2017 PRECIPITATION OUTLOOK INDICATES ENHANCED PROBABILITIES OF 
ABOVE-MEDIAN PRECIPITATION FOR AREAS OF THE NORTHERN ROCKIES, NORTHERN PLAINS 
AND WESTERN AREAS OF THE GULF COAST. IN ALASKA, BELOW-MEDIAN SEASONAL 
PRECIPITATION AMOUNTS ARE FAVORED FOR WESTERN ALASKA.
EQUAL CHANCES (EC) ARE FORECAST OVER AREAS WHERE ODDS OF ABOVE-, BELOW-, OR 
NEAR-NORMAL SEASONAL MEAN TEMPERATURES AND SEASONAL ACCUMULATED PRECIPITATION 
AMOUNTS ARE EXPECTED TO BE SIMILAR TO CLIMATOLOGICAL PROBABILITIES.
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
OCEANIC AND ATMOSPHERIC OBSERVATIONS ACROSS THE EQUATORIAL PACIFIC AS A WHOLE 
INDICATE THAT ENSO-NEUTRAL CONDITIONS ARE NOW IN PLACE. A RESIDUAL, GENERALLY 
SMALL, AREA OF BELOW NORMAL SEA SURFACE TEMPERATURES (SSTS) PERSISTS IN 
PROXIMITY TO THE DATE LINE, BUT IN MOST AREAS ALONG THE EQUATOR, OCEAN SURFACE 
TEMPERATURES ARE NOW ABOVE AVERAGE, ESPECIALLY FOR THE EASTERN AREAS OF THE 
BASIN WHERE THE LATEST WEEKLY VALUE OF THE NINO1+2 INDEX WAS +2.1 DEGREES C.
AT DEPTH, THE UPPER-OCEAN (TOP 300 METERS) HEAT CONTENT ANOMALY SUMMED ACROSS 
THE BASIN FROM THE DATE LINE TO 100W BECAME POSITIVE DURING JANUARY AND 
CONTINUED TO INCREASE DURING FEBRUARY INTO EARLY MARCH. IT NOW REFLECTS A VALUE 
OF +0.4 DEGREES C INDICATING CONSIDERABLE AREAS OF ABOVE-AVERAGE OCEAN 
TEMPERATURES BELOW THE SURFACE. 
IN THE ATMOSPHERE OVER THE PAST MONTH, EASTERLY WIND ANOMALIES CONTINUED TO BE 
OBSERVED OVER THE WESTERN TROPICAL PACIFIC. OVER THE SAME PERIOD, ANOMALOUS 
TROPICAL CONVECTION INDICATED CONTINUED SUPPRESSED CONVECTION IN THE CENTRAL 
PACIFIC BUT CONTINUING ENHANCED CONVECTION IN THE FAR WESTERN PACIFIC PRIMARILY 
NORTH OF THE EQUATOR. THE REMAINING DIPOLE IN ANOMALOUS CONVECTION INDICATES 
SOME SIGNATURES OF THE PAST WEAK LA NINA EVENT HAVE BEEN SLOW TO FADE.
PROGNOSTIC DISCUSSION OF SST FORECASTS
THE CPC SST CONSOLIDATION FORECAST, WHICH INCLUDES THREE STATISTICAL FORECASTS 
ALONG WITH THE CFS, PREDICTS ENSO-NEUTRAL CONDITIONS WILL PERSIST FROM NOW 
UNTIL THE UPCOMING WINTER SEASON. THERE IS A CONSIDERABLE DIFFERENCE, HOWEVER, 
BETWEEN THE CFS AND THE STATISTICAL GUIDANCE AS THE CFS FAVORS AN INCREASE IN 
SST QUITE EARLY IN THE OUTLOOK PERIOD ENTERING EL NINO CONDITIONS DURING THE 
AMJ 2017 SEASON WHILE THE AFOREMENTIONED STATISTICAL TOOLS FAVOR ENSO-NEUTRAL 
CONDITIONS.  THIS SEPARATION BETWEEN THE STATISTICAL AND DYNAMICAL MODELS IS 
ALSO DEPICTED BY THE LATEST IRI NINO3.4 SST FORECAST PLUME. MOREOVER, FORECASTS 
FROM THE DYNAMICAL SUITE OF MODELS FROM THE NMME ALSO INDICATES A MORE ROBUST 
AND EARLIER INCREASE IN NINO3.4 SST DURING THE SPRING AND SUMMER MONTHS. THE 
LATEST OFFICIAL  ENSO OUTLOOK FROM CPC/IRI FAVORS ENSO-NEUTRAL CONDITIONS TO 
CONTINUE THROUGH AT LEAST THE NORTHERN HEMISPHERE SPRING WITH INCREASING ODDS 
FOR THE DEVELOPMENT OF EL NINO CONDITIONS AS AUTUMN APPROACHES WITH 
PROBABILITIES FOR EL NINO REACHING NEAR 50% BY JAS 2017 AND APPROXIMATELY 
REMAINING AT THESE ODDS THROUGH OND 2017.      AT THE CURRENT TIME, THE 
PROSPECTS FOR A ENSO COLD EVENT ARE SMALL (UNDER 10%) FOR MUCH OF THE OUTLOOK 
PERIOD.
PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS
THE PRIMARY TOOLS USED FOR THIS SET OF OUTLOOKS INCLUDED BOTH STATISTICAL AND 
DYNAMICAL MODEL FORECAST INFORMATION AND WHERE APPROPRIATE LONG TERM TRENDS. 
THE DYNAMICAL MODEL GUIDANCE FROM CFS, NMME AND IMME (AND THEIR PARTICIPANT 
INDIVIDUAL MODELS) WERE IMPORTANT CONTRIBUTORS TO THE OUTLOOKS THROUGH ASO 
2017. ANTECEDENT SOIL MOISTURE AND SNOWPACK ANOMALIES IN CERTAIN REGIONS WERE 
ALSO INCLUDED IN THE OUTLOOKS WHERE APPROPRIATE, PRIMARILY AT EARLY LEADS. THE 
FAVORED ENSO-NEUTRAL CONDITIONS EARLY IN THE OUTLOOK PERIOD UNDERPINNED THE SET 
OF OUTLOOKS, ALTHOUGH THE LOW THREAT OF LA NINA CONDITIONS THROUGHOUT MUCH OF 
THE OUTLOOK PERIOD AS WELL AS INCREASING CHANCES (ALBEIT WITH HIGH UNCERTAINTY) 
FOR EL NINO WAS CONSIDERED IN MAKING SMALL CHANGES IN SOME OF THE OUTLOOKS AT 
MIDDLE AND LATER LEADS.   
PROGNOSTIC DISCUSSION OF OUTLOOKS - AMJ 2017 TO AMJ 2018
TEMPERATURE
THE LATEST AMJ 2017 TEMPERATURE OUTLOOK INDICATES GENERALLY MINOR CHANGES FROM 
THE PREVIOUS OUTLOOK. AS SHOWN, ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MUCH 
OF THE FORECAST DOMAIN. FOR THE CONTIGUOUS U.S., THERE IS AN ENHANCED 
LIKELIHOOD OF ABOVE-NORMAL SEASONAL MEAN TEMPERATURES FOR A REGION STRETCHING 
FROM THE SOUTHWEST, EASTWARD TO INCLUDE MUCH OF THE CENTRAL AND EASTERN U.S. 
THE GREATEST ODDS (EXCEEDING 50% PROBABILITY) ARE LOCATED ACROSS THE 
SOUTH-CENTRAL PLAINS AND  EASTERN CONUS. SHORT TERM CLIMATE PREDICTION MODELS 
(CFS, ECMWF, NMME SUITE AND IMME SUITE) OVERWHELMINGLY SUPPORTED THE 
CONTINUATION OF THIS SOLUTION INTO AND THROUGH THE SPRING WITH THE CALIBRATED 
PROBABILISTIC GUIDANCE FROM THE NMME INDICATING 50% OR GREATER ODDS FOR 
RELATIVE WARMTH IN THE AREAS HIGHLIGHTED WITH THE LARGEST OUTLOOK 
PROBABILITIES. NEGATIVE SOIL MOISTURE DEPARTURES IN SOME AREAS OF THIS 
DESIGNATED REGION ALSO CONTRIBUTED TO THE FAVORED ANOMALOUS WARMTH. SOME 
STATISTICAL FORECAST TOOLS AND LONG TERM TRENDS FURTHER SUPPORTED THE OUTLOOK.
POSITIVE SOIL MOISTURE DEPARTURES AND ELEVATED SNOWPACK IN SOME AREAS ACROSS 
THE NORTHERN TIER OF THE U.S. FROM THE NORTHERN HIGH PLAINS WESTWARD TO INCLUDE 
MUCH OF THE WEST, ALONG WITH WEAK SHORT TERM CLIMATE PREDICTION MODEL SIGNALS 
IN THESE AREAS RESULTED IN A DESIGNATION OF EQUAL CHANCES (EC) OR A REDUCTION 
IN PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES FROM THE PREVIOUS OUTLOOK IN 
THESE REGIONS.    
MANY OF THE REMAINING TEMPERATURE OUTLOOK MAPS SAW LITTLE CHANGE FROM THE 
PREVIOUS SET OF OUTLOOKS AS STATISTICAL AND DYNAMICAL FORECAST TOOL INDICATORS 
DID NOT VARY STRONGLY. SOME EXCEPTIONS INCLUDE THE FOLLOWING. SLIGHTLY LOWER 
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE NOW INDICATED FOR AREAS OF THE 
WEST DURING MJJ 2017 DUE TO PREVIOUSLY MENTIONED INITIAL LAND SURFACE 
CONDITIONS. WARMER GUIDANCE SUPPORTED AN INCREASE IN PROBABILITIES FOR ABOVE 
NORMAL TEMPERATURES FOR THE EASTERN U.S. DURING JJA, JAS AND ASO 2017. LOW 
PROBABILITIES FOR LA NINA CONDITIONS AND CONSEQUENTLY ELEVATED ODDS FOR EL NINO 
CONDITIONS POTENTIALLY ENTERING THE AUTUMN FAVORED A SLIGHT INCREASE IN 
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ALONG THE NORTHERN TIER IN THE 
CENTRAL AND EASTERN CONUS FOR SON, OND 2017 AND NDJ 2017-2018. 
FOR ALASKA, HIGH PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE INDICATED FOR 
THE NORTH SLOPE DUE TO RECENT TRENDS IN SEA ICE COVERAGE AND TIMING DURING SON 
AND OND 2017.
PRECIPITATION
FOR PRECIPITATION, THE AMJ 2017 OUTLOOK FAVORS ABOVE-MEDIAN PRECIPITATION FOR A 
REGION ACROSS THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS AS WELL AS ALONG 
THE WESTERN GULF COAST. BELOW-MEDIAN PRECIPITATION IS MOST LIKELY FOR AREAS OF 
WESTERN ALASKA INCLUDING THE ALEUTIANS. THE OUTLOOK IS PRIMARILY BASED ON 
AVAILABLE DYNAMICAL MODEL GUIDANCE AND LONG TERM TRENDS IN LOCATIONS WHERE THEY 
ARE DEEMED SOMEWHAT RELIABLE (I.E., NORTHERN ROCKIES, NORTHERN PLAINS). 
HIGHLIGHTED AREAS FOR THE MJJ THROUGH ASO 2017 SEASONS ARE IN AREAS WHERE THERE 
WAS CONSISTENT, ALBEIT OFTEN WEAK, SIGNATURES INDICATED BY CALIBRATED 
PROBABILISTIC GUIDANCE FROM THE NMME SUITE OF MODELS. THIS INCLUDES A 
CONTINUATION OF ELEVATED ODDS FOR ABOVE-MEDIAN PRECIPITATION FOR AREAS IN THE 
NORTHERN ROCKIES AND NORTHERN HIGH PLAINS. BY ASO 2017, CONSIDERATIONS AS NOTED 
ABOVE REGARDING INCREASING ODDS FOR EL NINO ALLOW A SLIGHT SOUTHWARD SHIFT OF 
THIS REGION. BELOW-MEDIAN PRECIPITATION CONTINUES FOR PARTS OF WESTERN ALASKA 
IN MJJ 2017 AND IS INTRODUCED IN MJJ AND JJA 2017 NEAR THE OHIO VALLEY. THERE 
IS A SLIGHT TILT IN THE ODDS FOR ABOVE MEDIAN PRECIPITATION FOR PORTIONS OF 
EASTERN MAINLAND ALASKA FROM MJJ TO JAS 2017.
FOR LATER LEADS, THE LOW PROBABILITIES FOR LA NINA AT THE CURRENT TIME AND 
CONSEQUENTLY ELEVATED ODDS FOR POTENTIAL EL NINO CONDITIONS RESULTED IN REMOVAL 
OF SOME DRY SIGNALS IN PREVIOUS OUTLOOKS ACROSS THE SOUTHERN TIER OF THE U.S., 
IN PARTICULAR THE SOUTHEAST CONUS BEGINNING IN NDJ 2017-2018.      
FORECASTER: JON GOTTSCHALCK
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/LONG_RANGE/TOOLS.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/PRODUCTS/SOILMST_MONITORING/US/OUTLOOK/OUTLOOK.SHTM
L
(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 APR 20 2017
1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 
FORECAST RELEASE.
$$