90 Day Narrative

703 
FXUS05 KWBC 171331
PMD90D
PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EST THU JAN 17 2019
SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS
THE FEBRUARY-MARCH-APRIL (FMA) 2019 TEMPERATURE OUTLOOK FAVORS ABOVE NORMAL 
TEMPERATURES FOR APPROXIMATELY THE WESTERN HALF OF THE LOWER 48 STATES, FAR 
SOUTHERN FLORIDA, AND ALASKA. PROBABILITIES EXCEED 60% OVER THE PACIFIC 
NORTHWEST, THE ALASKA PANHANDLE, AND SOUTHEASTERN MAINLAND ALASKA. BELOW NORMAL 
TEMPERATURES ARE FAVORED OVER THE OHIO AND TENNESSEE VALLEYS, AND PARTS OF 
ADJACENT STATES. THIS TEMPERATURE OUTLOOK IS BASED LARGELY ON RECENT DYNAMICAL 
AND STATISTICAL MODEL OUTPUT, TEMPERATURE TRENDS, AND TO A DECREASING EXTENT, 
EFFECTS RELATED TO AN EL NINO.
THE FMA 2019 PRECIPITATION OUTLOOK INDICATES ENHANCED ODDS OF ABOVE NORMAL 
PRECIPITATION AMOUNTS FROM SOUTH-CENTRAL ALASKA TO THE SOUTHERN ALASKA 
PANHANDLE, AND FOR THE SOUTHEASTERN CONUS. ABOVE NORMAL PRECIPITATION IS ALSO 
FAVORED FROM THE FOUR CORNERS REGION EASTWARD TO CENTRAL PORTIONS OF THE HIGH 
PLAINS. BELOW NORMAL PRECIPITATION IS FAVORED OVER NORTHERN CALIFORNIA, OREGON, 
AND PARTS OF ADJACENT STATES. ENHANCED ODDS OF LOWER TERCILE PRECIPITATION 
AMOUNTS ARE ALSO PREDICTED OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY, THE 
OHIO VALLEY, AND THE SOUTHERN GREAT LAKES REGION. THIS PRECIPITATION OUTLOOK IS 
BASED LARGELY ON RECENT DYNAMICAL AND STATISTICAL MODEL OUTPUT, HISTORICAL 
PRECIPITATION TRENDS, AND TO A DECREASING EXTENT, EFFECTS RELATED TO AN EL NINO.
EQUAL CHANCES (EC) OF BELOW, NEAR, AND ABOVE NORMAL SEASONAL MEAN TEMPERATURES 
OR 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
RECENT OBSERVATIONS SHOW SEA-SURFACE TEMPERATURES (SST) AND SUBSURFACE 
TEMPERATURES ACROSS MOST OF THE EQUATORIAL PACIFIC CONTINUE TO BE ABOVE 
AVERAGE. DURING THE PAST MONTH, SST ANOMALIES RANGED FROM +0.5C TO +2.0C OVER 
MOST OF THIS REGION, AND SUBSURFACE ANOMALIES RANGED FROM +0.5C TO +4.0C FROM 
NEAR THE SURFACE TO A DEPTH OF 175 METERS. THE UPPER-OCEAN (TOP 300 METERS) 
HEAT CONTENT ACROSS THE NEAR-EQUATORIAL CENTRAL AND EASTERN PACIFIC PEAKED IN 
MID-OCTOBER 2018, AND HAS DECLINED FAIRLY RAPIDLY SINCE THEN. THE LATEST WEEKLY 
SST DEPARTURE FOR THE NINO 3.4 REGION DROPPED THIS PAST WEEK FROM +0.7C TO 
+0.4C . ENHANCED ATMOSPHERIC CONVECTION REMAINED RELATIVELY STATIONARY WEST OF 
THE DATE LINE DURING THE PAST 30-DAYS, AND CONCURRENTLY FLARED UP ALONG THE 
SOUTH PACIFIC CONVERGENCE ZONE. SUPPRESSED CONVECTION WAS OBSERVED EAST OF THE 
DATE LINE; AND NEAR TO BELOW NORMAL CONVECTION WAS NOTED OVER INDONESIA. 
LOW-LEVEL (850-HPA) AND UPPER-LEVEL (200-HPA) WINDS WERE GENERALLY CLOSE TO THE 
LONG-TERM AVERAGE OVER MUCH OF THE TROPICAL PACIFIC.
DESPITE RELATIVELY WARM OCEAN TEMPERATURES OVER THE TROPICAL PACIFIC, THERE IS 
STILL NO CLEAR COUPLING BETWEEN THIS WARM WATER AND OVERLYING ATMOSPHERIC 
CONVECTION. THIS LACK OF COUPLING HAS INTERFERED WITH THE TYPICAL MATURATION 
PROCESS OF A DEVELOPING EL NINO. INSTEAD, SUBSEASONAL VARIABILITY ASSOCIATED 
WITH EPISODES OF ROBUST MJO ACTIVITY HAVE DOMINATED THE U.S. CLIMATE SINCE 
OCTOBER 2018. THE COMBINED EFFECT OF THE OCEAN-ATMOSPHERE SYSTEM IS MORE 
CONSISTENT WITH ENSO-NEUTRAL THAN IT IS WITH EL NINO.
IN THE NEAR-TERM, THERE IS NO OBVIOUS INDICATION THAT THIS LONG-AWAITED 
OCEAN-ATMOSPHERE COUPLING WILL TAKE PLACE BEFORE THE END OF BOREAL WINTER. THE 
FMA 2019 SEASONAL OUTLOOK IS THEREFORE BASED PRIMARILY ON THE EXPECTATION OF 
CONTINUED ROBUST MJO ACTIVITY WITH LESS OF AN INFLUENCE ANTICIPATED FROM A WEAK 
(OR NOMINAL) EL NINO THAT MAY STILL FORM. ACCORDING TO THE LATEST ENSO 
DIAGNOSTIC DISCUSSION ISSUED BY CPC ON 10 JANUARY 2019, THERE IS A 65% CHANCE 
THAT EL NINO WILL FORM AND CONTINUE THROUGH THE NORTHERN HEMISPHERE SPRING 
2019. HOWEVER, IT APPEARS THAT ANY EL NINO THAT DOES FORM WILL ONLY BE OF 
NOMINAL OR WEAK INTENSITY.
PROGNOSTIC DISCUSSION OF SST FORECASTS
THE CPC SST CONSOLIDATION TOOL FOR NINO 3.4 (WHICH INCLUDES THE CFS, CA, CCA, 
AND MARKOV SST PREDICTIONS) DEPICTS A MARGINAL EL NINO DURING FMA AND MAM 2019, 
BECOMING ENSO-NEUTRAL FOR THE REMAINDER OF 2019. THE CFS MODEL PRODUCES THE 
WARMEST SOLUTION OVERALL, WITH A PREDICTED NINO 3.4 SST ANOMALY CLOSE TO +1.0C 
(FMA), SLOWLY DROPPING TO ABOUT +0.7C BY JAS. HOWEVER, INDIVIDUAL ENSEMBLE 
MEMBERS FORECAST A LARGE SPREAD IN SOLUTIONS, FROM NEAR +2.3C DOWN TO -0.5C, 
WITH THE COOLEST OUTLYING MEMBER PREDICTING -1.5C. THE NMME AND IMME SST PLUMES 
FORECAST AN SST ANOMALY AT OR SOMEWHAT ABOVE +0.5C THROUGH JUNE 2019.
PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS
THE TEMPERATURE AND PRECIPITATION OUTLOOKS WERE BASED ON DYNAMICAL MODEL 
GUIDANCE WHICH INCLUDED THE CFS ALONG WITH THE NMME AND ITS CALIBRATED 
PROBABILITIES THROUGH JJA 2019. THE IMME WAS USED THROUGH MJJ 2019. STATISTICAL 
FORECAST MODELS SUCH AS THE COMBINED ENSO-OCN TOOL, THE EXPERIMENTAL CBAM, 
SMLR, CCA, AND OCN WERE CONSIDERED. LONG-TERM TRENDS WERE WEIGHED MORE HEAVILY 
IN THE LATER OUTLOOKS, FROM  ASO 2019 THROUGH FMA 2020.
THE MJO IS EXPECTED TO REMAIN A MAJOR CONTRIBUTOR TO ANOMALOUS TROPICAL 
CONVECTION AND ITS ASSOCIATED INTERACTION WITH THE MID-LATITUDE CIRCULATION 
PATTERN, ESPECIALLY IN FEBRUARY 2019. UNCERTAINTY REMAINS ON HOW MUCH BLOCKING 
AT THE HIGH LATITUDES DEVELOPS BY FEBRUARY AND ITS LONGEVITY WITH LIMITED 
CONFIDENCE ON THE FUTURE EVOLUTION OF THE ARCTIC OSCILLATION (AO) AND NORTH 
ATLANTIC OSCILLATION (NAO). CLIMATE EFFECTS TYPICALLY ASSOCIATED WITH EL NINO 
DURING THE WINTER AND SPRING WERE CONSIDERED, BUT DOWNPLAYED SIGNIFICANTLY.
PROGNOSTIC DISCUSSION OF OUTLOOKS - FMA 2019 TO FMA 2020
TEMPERATURE
THE GREATEST UNCERTAINTY WITH THE FMA 2019 SEASONAL TEMPERATURE OUTLOOK IS IN 
THE PREDICTED COVERAGE OF FAVORED BELOW NORMAL TEMPERATURES IN THE EAST. THIS 
IS BASED  ON SEVERAL CONSIDERATIONS WHICH INCLUDE: THE EXPERIMENTAL CBAM TOOL, 
LAGGED MJO COMPOSITES BASED ON THE EXPECTATION OF ENHANCED TROPICAL CONVECTION 
PROPAGATING ACROSS THE WESTERN PACIFIC (RMM PHASES 6 AND 7), AND THE GEFS 
CONSISTENTLY FORECASTING AN IMPRESSIVELY NEGATIVE AO AT LEAST FOR THE START OF 
FEBRUARY. AS MENTIONED EARLIER, THE LACK OF CLEAR OCEAN-ATMOSPHERE COUPLING 
MAKES SIGNIFICANT ENSO-RELATED IMPACTS MUCH LESS LIKELY ACROSS THE U.S. AS IS 
OFTEN THE CASE, WHEN ENSO IS WEAK, OTHER CONTRIBUTORS SUCH AS THE AO AND MJO 
CAN PLAY A LARGER ROLE IN U.S. WINTER CLIMATE VARIABILITY. THE EXPECTATION OF A 
HIGHLY VARIABLE TEMPERATURE PATTERN DURING THE 3-MONTH PERIOD RESULTS IN A 
FORECAST OF EC ACROSS MOST OF THE REMAINDER OF THE EASTERN CONUS. THE 
WIDESPREAD AREA OF FAVORED ABOVE NORMAL TEMPERATURES, WHICH INCLUDES MOST OF 
THE WESTERN CONUS AND ALASKA, IS SUPPORTED BY MANY OF THE TOOLS, SUCH AS THE 
CFS, THE CALIBRATED NMME (PAC) AND MOST OF ITS INPUT MODELS, ENSO-OCN, SMLR, 
CCA, AND OCN, AND TO A LESSER EXTENT, THE EXPERIMENTAL CBAM TOOL.
IN MAM AND AMJ 2019, THE OUTLOOKS DEPICT THE EXPANSION OF FAVORED ABOVE NORMAL 
TEMPERATURES ACROSS THE EASTERN CONUS, AS PREDICTED BY ENSO-OCN, CBAM, THE NMME 
PAC, AND THE IMME. IN AMJ AND MJJ, PROBABILITIES FOR ABOVE NORMAL TEMPERATURES 
REACH A MAXIMUM ACROSS NORTHERN ALASKA, IN PART DUE TO THE EARLIER BREAKUP OF 
ICE IN RECENT DECADES AND WARMING TEMPERATURE TRENDS. BY JJA AND JAS, ABOVE 
NORMAL TEMPERATURES ARE FAVORED ACROSS MUCH OF THE LOWER 48 STATES AND ALASKA, 
PRIMARILY RELATED TO HISTORICAL TEMPERATURE TRENDS, BUT ALSO SUPPORTED BY CBAM. 
TRENDS FOR WARMTH ARE PROMINENT ACROSS THE NORTHEAST DURING THE SUMMER AND 
EARLY AUTUMN (JJA THROUGH OND). FOR JJA AND JAS, EC IS FAVORED ACROSS THE 
NORTH-CENTRAL CONUS, SUPPORTED BY CBAM (WHICH ALSO PREDICTS BELOW NORMAL 
TEMPERATURES ACROSS PART OF THIS REGION), NMME (PAC) TO SOME EXTENT, ENSO-OCN, 
AND CCA. FOR THE REMAINING SEASONS, ASO 2019 THROUGH FMA 2020, THE OUTLOOKS ARE 
BASED PRIMARILY ON HISTORICAL TEMPERATURE TRENDS AS EXPRESSED IN THE ENSO-OCN 
TOOL.
PRECIPITATION
THE FMA 2019 SEASONAL PRECIPITATION OUTLOOK FAVORS ABOVE NORMAL (UPPER TERCILE) 
PRECIPITATION FROM SOUTH-CENTRAL ALASKA TO THE SOUTHERN ALASKA PANHANDLE, AND 
CENTRAL AND SOUTHERN PORTIONS OF BOTH THE ROCKIES AND HIGH PLAINS. ABOVE NORMAL 
PRECIPITATION IS ALSO FAVORED ACROSS THE SOUTHEAST AND EAST GULF REGIONS. THESE 
AREAS ARE SUPPORTED BY THE NMME (PAC), CBAM, AND TO SOME EXTENT THE IMME AND 
CFS.  THE GFDL FLOR AND NCAR MODELS ALSO LEND SOME SUPPORT FOR THESE PREDICTED 
REGIONS OF FAVORED ABOVE NORMAL PRECIPITATION. BELOW NORMAL (LOWER TERCILE) 
PRECIPITATION IS FAVORED OVER OREGON, NORTHERN CALIFORNIA, AND PARTS OF 
NEIGHBORING STATES, AND THE MID-UPPER MISSISSIPPI VALLEY, SOUTHERN GREAT LAKES 
REGION, AND OHIO AND TENNESSEE VALLEYS. THE UN-CALIBRATED NMME AND SOME OF ITS 
INPUTS PREDICT THESE TWO DRY SIGNALS. THE IMME, CBAM, AND CFS ALSO CONTRIBUTE 
TOWARD THESE PREDICTED PRECIPITATION ANOMALIES. THE FMA 2019 PRECIPITATION 
OUTLOOK ACKNOWLEDGES THE DECREASING CHANCES OF SIGNIFICANT ENSO-RELATED 
ANOMALIES, AND THESE DEPARTURES HAVE BEEN SUBSTANTIALLY SCALED BACK IN SPATIAL 
COVERAGE. STILL, THERE REMAINS AN OUTSIDE CHANCE THAT THE OCEAN-ATMOSPHERE 
SYSTEM COULD COUPLE LATE THIS WINTER, SO EL NINO EFFECTS CAN NOT BE RULED OUT 
ENTIRELY AT THIS TIME FOR THE U.S. 
IN MAM, THE PRECIPITATION OUTLOOK RETAINS THE WET SIGNAL OVER SOUTHERN PORTIONS 
OF ALASKA, THOUGH THE COVERAGE DIMINISHES. FROM MAM THROUGH MJJ 2019, VARIOUS 
STATISTICAL AND DYNAMICAL MODELS, AND HISTORICAL PRECIPITATION TRENDS, TEND TO 
SLOWLY DECREASE THE COVERAGE OF FAVORED ABOVE NORMAL PRECIPITATION OVER THE 
SOUTHEAST, WHILE INCREASING IT OVER THE WEST-CENTRAL CONUS, AND THEN INTO THE 
MIDDLE AND UPPER MISSISSIPPI VALLEY AND OHIO VALLEY. BY JJA AND JAS, LONG-TERM 
TRENDS (AND THE CBAM TOOL TO SOME DEGREE) FAVOR DRYNESS IN THE NORTHERN ROCKIES 
AND NORTHERN INTERMOUNTAIN REGION, AND WETNESS IN MUCH OF ALASKA AND FROM THE 
MIDDLE MISSISSIPPI VALLEY EASTWARD TOWARDS THE MID-ATLANTIC AND NORTHEAST. FOR 
THE REMAINING SEASONS ASO 2019 THROUGH FMA 2020, THE SEASONAL PRECIPITATION 
OUTLOOKS ARE ALMOST EXCLUSIVELY BASED ON LONG-TERM PRECIPITATION TRENDS. 
FORECASTER: ANTHONY ARTUSA
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 FEB 21 2019
1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 
FORECAST RELEASE.
$$