Skip Navigation Links www.nws.noaa.gov 
NOAA logo - Click to go to the NOAA home page National Weather Service   NWS logo - Click to go to the NWS home page
Climate Prediction Center
 
 

CPC Search
About Us
   Our Mission
   Who We Are

Contact Us
   CPC Information
   CPC Web Team

Official 90-day Outlooks are issued once each month near mid-month at 8:30am Eastern Time. Please consult the schedule of 30 & 90-day outlooks for exact release dates.

Text Discussions
   90day Prognostic
   30day Prognostic
   Hawaiian
   Tools


More Outlooks
    0.5mn NDJ 2018
    1.5mn DJF 2018
    2.5mn JFM 2019
    3.5mn FMA 2019
    4.5mn MAM 2019
    5.5mn AMJ 2019
    6.5mn MJJ 2019
    7.5mn JJA 2019
    8.5mn JAS 2019
    9.5mn ASO 2019
   10.5mn SON 2019
   11.5mn OND 2019
   12.5mn NDJ 2019
    0.5mn Nov 2018


Tools Used (see Discussion for explanation)
   CCA
   OCN
   CMP
   SMT
   POE
 
HOME> Outlook Maps>Seasonal Forecast Discussion
 
PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS 
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EDT THU OCT 18 2018

SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS

THIS SECTION OF THE SEASONAL OUTLOOK MESSAGE SUMMARIZES THE FIRST FORECAST IN
THE SET, THE NOVEMBER-DECEMBER-JANUARY (NDJ) 2018-2019 SEASONAL OUTLOOK.
DESCRIPTION OF THE SUBSEQUENT OUTLOOKS, CLIMATE FACTORS CONSIDERED, AND
SPECIFIC FORECAST RATIONALE FOR ALL OUTLOOKS ARE PROVIDED IN THE LAST TWO
SECTIONS OF THE MESSAGE.

THE NDJ 2018-2019 TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL SEASONAL MEAN
TEMPERATURES FOR MUCH OF THE FORECAST DOMAIN TO INCLUDE ALL OF ALASKA AND MOST
OF THE WESTERN AND NORTHERN CONTIGUOUS U.S. THE GREATEST PROBABILITIES FOR
ABOVE-NORMAL TEMPERATURES ARE INDICATED FOR WESTERN AND NORTHERN ALASKA AND TO
A LESSER DEGREE THE PACIFIC NORTHWEST. FOR SEASONAL TOTAL PRECIPITATION AMOUNTS
DURING NDJ 2018-2019, THERE ARE MODESTLY ELEVATED CHANCES OF ABOVE-NORMAL
PRECIPITATION FOR MOST OF THE SOUTHERN TIER OF THE CONTIGUOUS U.S., THE CENTRAL
EASTERN SEABOARD, AND SOUTHERN ALASKA.

EQUAL CHANCES (EC) FOR ABOVE-, NEAR-, OR BELOW-NORMAL SEASONAL MEAN
TEMPERATURES OR SEASONAL TOTAL PRECIPITATION AMOUNTS ARE INDICATED IN AREAS
WHERE THE LIKELIHOOD OF THESE VARIABLES ARE FAVORED TO BE SIMILAR TO
CLIMATOLOGICAL PROBABILITIES. THE REASONS FOR THIS CAN BE A COMBINATION OF
WEAKLY DEFINED OR NON-RELIABLE CLIMATE FACTORS AS WELL AS CONSIDERABLE SPREAD
IN FORECAST TOOL SOLUTIONS.

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

STARTING WITH OCEAN CONDITIONS, WE CONTINUE TO REMAIN IN ENSO-NEUTRAL
CONDITIONS THROUGH EARLY OCTOBER AND THE EL NINO WATCH CONTINUES. IN RECENT
WEEKS, HOWEVER, OBSERVATIONS ACROSS THE GLOBAL TROPICS HAVE TRENDED TOWARD MORE
FAVORABLE CONDITIONS FOR DEVELOPMENT OF EL NINO IN THE NEXT COUPLE OF MONTHS.
SEA SURFACE TEMPERATURES (SSTS) ARE ABOVE-NORMAL ACROSS MOST OF THE EQUATORIAL
PACIFIC BASIN, GENERALLY RANGING FROM +0.5 - +1.0 DEGREES C. THE MOST RECENT
WEEKLY VALUES OF THE NINO4 AND NINO3.4 INDICES ARE NOW +0.9 AND +0.6 DEGREES C
RESPECTIVELY. THIS SOMEWHAT RAPID CHANGE WAS CONSIDERABLY AIDED BY THE
DEVELOPMENT OF A WESTERLY WIND BURST (WWB) AND EVOLUTION OF AN ONGOING MJO
EVENT AND THE ASSOCIATED WESTERLY LOW-LEVEL WIND ANOMALIES. A STRONG
DOWNWELLING OCEANIC KELVIN WAVE WAS INITIATED AS A RESULT OF THIS SIGNIFICANT
WEAKENING OF THE PACIFIC BASIN TRADE WINDS DUE TO THESE EVENTS AND CONTINUES TO
SHIFT EASTWARD ACROSS THE PACIFIC BASIN AT DEPTH. ACCORDINGLY, THE EQUATORIAL
UPPER-OCEAN HEAT CONTENT HAS INCREASED CONSIDERABLY DURING SEPTEMBER AND EARLY
OCTOBER MAKING THE DEVELOPMENT OF EL NINO SOMEWHAT MORE LIKELY. SPECIFIC
NINO3.4 SST FORECASTS ARE REVIEWED IN THE SECTION BELOW.

THE ATMOSPHERIC CONDITIONS ASSOCIATED WITH A DEVELOPING EL NINO EVENT REMAIN
MODEST AT BEST. ALTHOUGH WESTERLY LOW-LEVEL WIND ANOMALIES ARE NOW PRESENT, ANY
ORGANIZED AREAS OF ENHANCED CONVECTION ARE NOT YET PRESENT. THIS IS MOST
LIKELY, HOWEVER, IN PART DUE TO THE COUNTER-ACTING EFFECT FROM LARGE SCALE
SUBSIDENCE ASSOCIATED WITH THE SUPPRESSED CONVECTIVE PHASE OF THE MJO.

TURNING TO CURRENT TERRESTRIAL CONDITIONS, WE NOTE MUCH ABOVE-NORMAL SOIL
MOISTURE ANOMALIES FROM TEXAS TO THE MIDWEST, EASTWARD TO THE GREAT LAKES,
MID-ATLANTIC AND PARTS OF THE NORTHEAST, WHILE DROUGHT CONDITIONS PERSIST
ACROSS MANY AREAS OF THE WEST. AS WE ARE ENTERING THE LATE AUTUMN AND WINTER
MONTHS, SOIL MOISTURE CONDITIONS, ALTHOUGH NEAR THE 99TH PERCENTILE IN MANY
AREAS, IS NOT EXPECTED TO CONTRIBUTE ANY SIGNIFICANT IMPACT TO THE CLIMATE
CONDITIONS OVER THE NEXT SEVERAL MONTHS. SNOW COVER ANOMALIES (BOTH NEGATIVE
AND POSITIVE) FOR SEPTEMBER AND THE FIRST HALF OF OCTOBER ARE IMPORTANT TO
NOTE. SNOWFALL OVER AREAS OF EURASIA AND ALASKA ARE CURRENTLY BELOW-NORMAL IN
MANY AREAS, BUT SNOWFALL HAS BEEN SUBSTANTIALLY ABOVE-NORMAL FOR PORTIONS OF
CENTRAL AND EASTERN CANADA.

PROGNOSTIC DISCUSSION OF SST FORECASTS

FORECASTS OF THE NINO3.4 SST ANOMALY HAVE NOT CHANGED VERY MUCH OVER THE PAST
FEW MONTHS TO FIRST ORDER. THE CPC CONSOLIDATION NINO3.4 SST ANOMALY FORECAST
MAINTAINS ITS RECENT PREDICTIONS OVER THE PAST SEVERAL MONTHS WITH A PEAK IN
POSITIVE ANOMALY DURING NDJ 2018-2019 OF JUST UNDER +1.0 DEGREE C AND THEN
SLOWLY DECREASES OVER THE COURSE OF THE WINTER AND SPRING MONTHS OF 2019,
ALTHOUGH THE FORECAST IS TEMPERED BY AN OUTLIER FORECAST FROM THE CCA
STATISTICAL MODEL. THIS MODEL FORECAST REMAINS IN ENSO-NEUTRAL TERRITORY
THROUGH THE WINTER AND INCREASES THEREAFTER. THE NMME NINO3.4 SST ANOMALY MODEL
GUIDANCE ALSO HAS REMAINED CONSISTENT OVER THE PAST FEW MONTHS AND CONTINUES TO
INDICATE A SLIGHTLY STRONGER EVENT (ENSEMBLE MEAN PEAKING AND PERSISTING
BETWEEN +1.0 - +1.2 DEGREES C) DURING THE WINTER AND SPRING MONTHS. THE
OFFICIAL CPC-IRI ENSO OUTLOOK FAVORS EL NINO THIS WINTER AND SPRING AT A
GREATER THAN 70% PROBABILITY THROUGH JFM 2019 AND THEN DECREASING TO NEAR 50%
BY AMJ 2019.

PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS

THIS SET OF OUTLOOKS UTILIZED TYPICAL IMPACTS ASSOCIATED WITH EL NINO EVENTS,
ALBEIT WITH THE UNDERSTANDING THAT THIS MOST LIKELY WILL BE A WEAK EVENT AND
NOTING THE CONFIDENCE IN THIS IMPACTS IN INTENSITY AND LOCATION IS SOMEWHAT
LOW.  MOREOVER, IT IS NOTED THAT DUE TO ITS LIKELY WEAK NATURE, THE VARIANCE
EXPLAINED IN THE MID-LATITUDES OVER THE EARLY PORTION OF THIS SET OF OUTLOOKS
FROM THE TROPICAL PACIFIC COULD VERY WELL BE LOW. OTHER FACTORS FROM BOTH THE
TROPICS (E.G., MJO) AND HIGH/POLAR LATITUDES (E.G., AO/NAO, NPO, ETC.) ARE
LIKELY TO FAVOR HIGH VARIABILITY OVER THE WINTER AND EARLY SPRING SEASONS AND
LIKELY WILL EXPLAIN CONSIDERABLY MORE VARIANCE IN THE UPCOMING SEASONAL MEANS
IN TEMPERATURE AND PRECIPITATION.

LOCAL COASTAL SSTS AND CONSIDERATIONS OF AREAS OF ANOMALOUS SNOWFALL WERE
CONSIDERED IN MAKING THE OUTLOOKS.

CONTRIBUTIONS TO THE OUTLOOKS ALSO INCLUDED BIAS-CORRECTED AND CALIBRATED
DYNAMICAL MODEL GUIDANCE FROM THE NMME AND IMME ENSEMBLE SUITES (BOTH ENSEMBLE
MEAN AND THEIR PARTICIPANT MODELS) THROUGH MAM 2019. EMPIRICAL AND STATISTICAL
FORECAST MODELS ALSO PLAYED A LARGE ROLE THROUGHOUT ALL FORECAST LEADS. THESE
INCLUDED GUIDANCE FROM A COMBINED ENSO-OCN TOOL, THE CCA, THE CA, AND
"BRIDGING" TECHNIQUES. MOREOVER, CONSOLIDATION FORECAST GUIDANCE PRODUCTS FROM
STATISTICAL ONLY, DYNAMICAL MODEL ONLY, AND COMBINED STATISTICAL AND DYNAMICAL
FORECAST TOOLS WAS HEAVILY UTILIZED. OCN ALSO WAS UTILIZED OFTEN THROUGHOUT THE
OUTLOOK LEADS FOR BOTH TEMPERATURE AND PRECIPITATION.

PROGNOSTIC DISCUSSION OF OUTLOOKS - NDJ 2018 TO NDJ 2019

TEMPERATURE

IN REVIEWING THE FIRST FOUR FORECAST LEADS THROUGH THE WINTER 2018-2019 AND
EARLY SPRING MONTHS IN 2019, THE NDJ AND DJF 2018-2019 TEMPERATURE OUTLOOKS ARE
SIMILAR AND DEPICT ELEVATED ODDS OF ABOVE-NORMAL TEMPERATURES FOR ALASKA AND
MUCH OF THE WESTERN AND NORTHERN CONUS WITH EC NOTED FOR THE SOUTHEAST. AS WE
PROGRESS THROUGH THE WINTER INTO THE EARLY SPRING, THE FORECAST SEQUENCE
DEPICTS A TENDENCY FOR THE ODDS OF ABOVE-NORMAL TEMPERATURES TO DECREASE ALONG
WITH FORECAST COVERAGE FIRST FOR THE OHIO VALLEY AND MID-ATLANTIC AND THEN
LATER IN THE GREAT LAKES AND NORTHEAST BY FMA 2019 WHERE EC IS FORECAST. IN
ADDITION, OVER THE SAME TIME, THERE IS AN EASTERN EXPANSION OF ENHANCED ODDS
FOR ABOVE-NORMAL TEMPERATURES ACROSS THE SOUTHERN PLAINS INTO THE SOUTHEAST
CONUS. FOR THESE LEADS, OTHER THAN AREAS IN ALASKA AND THE PACIFIC NORTHWEST,
THE PROBABILITIES ARE QUITE MODEST.

THIS DEPICTED EVOLUTION (VARIATION OF AREAS DENOTED AS EC) IN THE FORECAST OF
SEASONAL MEAN TEMPERATURES IS A RESULT OF CHANGING AREAS WITH THE GREATEST
UNCERTAINTY AND SO LOWER FORECAST CONFIDENCE. UNDERSTANDING THE WEAK NATURE OF
EL NINO ANTICIPATED THIS WINTER AND CONFRONTED BY CONSIDERABLE CONFLICTING
FORECAST TOOL INFORMATION IN THESE AREAS, EC IS FORECAST AT THIS TIME. DURING
NDJ AND DJF 2018-2019, DYNAMICAL MODEL GUIDANCE FROM THE NMME DEPICTS
CALIBRATED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES NEARLY UNANIMOUSLY
ACROSS MUCH OF THE NORTH IN AGREEMENT WITH THE AFOREMENTIONED STATISTICAL
FORECAST TOOLS AND OBJECTIVE, SKILL WEIGHTED CONSOLIDATION GUIDANCE PRODUCTS.

AS WE PROGRESS THROUGH THE WINTER, POSITIVE TEMPERATURE TRENDS IN MANY AREAS NO
LONGER EXIST AND CALIBRATED DYNAMICAL MODEL GUIDANCE PROBABILITIES DECREASE
SUBSTANTIALLY, ALONG WITH LITTLE HISTORICAL FORECAST SKILL INDICATED. AN
ADDITIONAL FACTOR IS THAT THE ECMWF SEASONAL PREDICTION FAVORS BELOW-NORMAL
TEMPERATURES FOR A CONSIDERABLE AREA THAT STRETCHES FROM THE SOUTHERN PLAINS
AND PARTS OF THE SOUTHEAST CONUS IN NDJ 2018-2019 TO AN EXPANDED AREA THAT
INCLUDES THE CENTRAL PLAINS, CENTRAL MISSISSIPPI VALLEY, OHIO VALLEY, AND
MID-ATLANTIC. MOREOVER, THE ENSO-OCN TOOL AND OBJECTIVE, SKILL WEIGHTED
CONSOLIDATION FORECAST TOOLS INDICATE A VARYING MIXTURE OF QUITE MODEST
PROBABILITIES FOR EITHER OF THE THREE FORECAST CATEGORIES.

IN ADDITION, UNCERTAINTIES IN THE PREDOMINATE PHASE OF THE AO/NAO AND MJO
ACTIVITY ESPECIALLY FROM MID-WINTER INTO EARLY SPRING MAKE A FORECAST OF EC NOT
AN UNREASONABLE CHOICE AS VARIABILITY OVERALL IS LIKELY TO BE HIGH AND DEPEND
ON CONSIDERABLE IMPACTS ASSOCIATED WITH BOTH TROPICAL AND HIGH LATITUDE
SUBSEASONAL VARIABILITY WHICH IS DIFFICULT TO PREDICT AT THESE FORECAST LEADS.

FOR ALASKA AND THE WESTERN CONUS, THERE IS LITTLE SUPPORT FOR ANY OTHER
FORECAST BESIDES ELEVATED ODDS FOR ABOVE-NORMAL TEMPERATURES FOR THIS PORTION
OF THE SET OF OUTLOOKS AS WELL AS THE REMAINING OUTLOOKS THROUGH NDJ 2019-2020.
THE PRIMARY DRIVER FOR THE OUTLOOKS FROM MJJ 2019 THROUGH NDJ 2019-2020 WERE
OCN, ENSO-OCN, AND STATISTICAL OBJECTIVE, SKILL WEIGHTED CONSOLIDATION
FORECAST TOOLS.

PRECIPITATION

THE OUTLOOKS FOR SEASONAL TOTAL PRECIPITATION AMOUNTS UTILIZED INFORMATION
CONSISTENT WITH AN ANTICIPATED (ALBEIT WEAK) EL NINO EVENT FROM NDJ 2018-2019
THROUGH MAM 2019. DYNAMICAL MODEL GUIDANCE FROM THE NMME AND IMME CONTRIBUTED
TO THE OUTLOOKS AS WELL THROUGH MAM 2019. GIVEN THE RANGE OF SOLUTIONS AND
GENERALLY WEAK INDICATORS FROM MANY OF THE FORECAST TOOLS, PROBABILITIES FOR
EITHER FORECAST CATEGORY (ABOVE- OR BELOW-NORMAL PRECIPITATION) ARE QUITE
MODEST, NOT REACHING 50% PROBABILITY FROM THE CLIMATOLOGICAL PROBABILITY OF 33%
UNTIL DJF 2018-2019 AND JFM 2019 WHEN A SMALL AREA FAVORING ABOVE-NORMAL
PRECIPITATION IS INDICATED FOR AN AREA IN SOUTHERN GEORGIA AND NORTHERN
FLORIDA. THIS AREA IS A PART OF A LARGER REGION OF FAVORED ABOVE-NORMAL
PRECIPITATION ACROSS THE SOUTHERN TIER OF THE CONUS THROUGH MAM 2019. PRIMARILY
SUPPORTED BY DYNAMICAL MODEL GUIDANCE, AN INCREASE IN COVERAGE OF THIS REGION
IN THE CENTRAL ROCKIES AND CENTRAL PLAINS DURING JFM AND FMA 2019 IS FORECAST.

BELOW-NORMAL PRECIPITATION IS FAVORED FOR PARTS OF PACIFIC NORTHWEST AND
NORTHERN ROCKIES IN NDJ 2018-2019 AND THEN PRIMARILY CENTERED ACROSS MONTANA
DURING JFM AND FMA 2019. SIMILARLY, BELOW NORMAL PRECIPITATION IS FAVORED FOR
PARTS OF THE GREAT LAKES AND LATER THE OHIO VALLEY OVER THE SEASONS FROM DJF
2018-2019 TO FMA 2019. EL NINO CONSIDERATIONS AND CONSISTENT DYNAMICAL MODEL
GUIDANCE FAVORED ELEVATED ODDS OF ABOVE-NORMAL PRECIPITATION FOR SOUTHERN
ALASKA THROUGH FMA 2019. THERE WAS CONSIDERABLE CONFLICTING FORECAST TOOL
INFORMATION (SEVERAL SOURCES) FOR THE EARLY LEADS ACROSS CALIFORNIA SO EC WAS
INDICATED AT THIS TIME FOR THIS REGION EXCEPT FOR A SMALL AREA IN SOUTHERN
CALIFORNIA.

FROM AMJ 2019 THROUGH NDJ 2019-2020, THE OUTLOOKS ARE BASED PREDOMINATELY ON
LONG TERM TRENDS AS DIAGNOSED BY OCN FOR EACH FORECAST SEASON. TO THIS END, THE
MOST BROAD AND CONSISTENT SIGNALS FOR THIS ARE ELEVATED ODDS FOR BELOW-NORMAL
PRECIPITATION IN THE NORTHERN ROCKIES FROM MJJ 2019 THROUGH JAS 2019 AND A
LARGER AREA FOR FAVORED ABOVE-NORMAL PRECIPITATION FOR PARTS OF THE GREAT
LAKES, NORTHEAST, OHIO VALLEY, AND MID-ATLANTIC FROM MJJ 2019 THROUGH OND 2019.

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 NOV 15 2018


1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011
FORECAST RELEASE.
$$

NOAA/ National Weather Service
National Centers for Environmental Prediction
Climate Prediction Center
5200 Auth Road
Camp Springs, Maryland 20746
Climate Prediction Center Web Team
Page last modified: January 17, 2006
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act
About Us
Career Opportunities