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 MJJ 2014
    1.5mn JJA 2014
    2.5mn JAS 2014
    3.5mn ASO 2014
    4.5mn SON 2014
    5.5mn OND 2014
    6.5mn NDJ 2014
    7.5mn DJF 2014
    8.5mn JFM 2015
    9.5mn FMA 2015
   10.5mn MAM 2015
   11.5mn AMJ 2015
   12.5mn MJJ 2015
    0.5mn May 2014


Tools Used (see Discussion for explanation)
   CCA
   OCN
   CMP
   SMT
   POE
 
HOME> Outlook Maps>Seasonal Forecast Discussion
 
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK 
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EDT THURSDAY APR 17 2014

30-DAY OUTLOOK DISCUSSION FOR MAY 2014

RECENT ATMOSPHERIC AND OCEANIC CONDITIONS IN THE TROPICAL PACIFIC BASIN
CONTINUE TO INDICATE ENSO-NEUTRAL CONDITIONS IN EARLY APRIL. PACIFIC SEA
SURFACE TEMPERATURE (SST) ANOMALIES HAVE BEEN STEADILY RISING ALONG EQUATOR
THROUGHOUT MUCH OF THE CENTRAL AND EASTERN PACIFIC OCEAN AND ARE NOW ABOVE
AVERAGE EXCEPT ALONG THE SOUTH AMERICAN COAST.  THERE ARE MANY INDICATORS THAT
SUGGEST THAT THE ENSO STATE IS EVOLVING TOWARD EL NINO. THESE INCLUDE RECENTLY
OBSERVED WESTERLY WIND ANOMALIES OVER MUCH OF THE CENTRAL AND WESTERN
EQUATORIAL PACIFIC, A MARKED INCREASE IN SUB-SURFACE OCEANIC HEAT CONTENT IN
THE PAST FEW WEEKS, AND A SLOW PROGRESSION OF ENHANCED CONVECTION ALONG THE
EQUATOR TOWARD THE CENTRAL PACIFIC. IN ADDITION, THERE IS AN INCREASING
CONSENSUS AMONG DYNAMICAL AND STATISTICAL FORECASTS THAT POSITIVE SST ANOMALIES
IN THE ENSO CRITICAL REGIONS OF THE PACIFIC WILL REACH MINIMAL THRESHOLDS FOR
EL NINO CONDITIONS BY SUMMER 2014. COMPOSITES OF PAST YEARS IN WHICH EL NINO
CONDITIONS DEVELOPED IN SUMMER WERE CONSIDERED FOR THE MAY OUTLOOK.

THE MAY OUTLOOK FOR MONTHLY MEAN TEMPERATURES INDICATES ELEVATED CHANCES FOR
BELOW-NORMAL TEMPERATURES FOR PORTIONS OF THE NORTHERN ROCKIES, THE NORTHERN
GREAT PLAINS, AND THE UPPER GREAT LAKES. THIS IS DUE TO INDICATIONS FROM THE
BOTH SMLR AND CFS, AND IS CONSISTENT WITH TEMPERATURES FROM COMPOSITES OF PAST
YEARS WITH DEVELOPING EL NINO CONDITIONS. ABOVE-NORMAL SOIL MOISTURE CONTENT IN
THE NORTHERN ROCKIES MAY ALSO ENHANCE THE CHANCES FOR BELOW-NORMAL
TEMPERATURES. THE CHANCES FOR BELOW-NORMAL TEMPERATURES NEAR THE SHORES OF THE
GREAT LAKES ARE FURTHER ENHANCED BY THE SIGNIFICANTLY BELOW-NORMAL WATER
TEMPERATURES THAT ARE EXPECTED TO PERSIST INTO MAY. MOST TOOLS INDICATE
ENHANCED ODDS FOR ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE SOUTHWESTERN
QUARTER OF THE CONUS AND PARTS OF THE SOUTHERN GREAT PLAINS. DRY SOIL MOISTURE
CONDITIONS ARE EXPECTED TO HELP INCREASE THE ODDS OF ABOVE NORMAL TEMPERATURES
IN THESE REGIONS. ABOVE-NORMAL SSTS NEAR SOUTHERN FLORIDA HELP ELEVATE CHANCES
FOR ABOVE-NORMAL AIR TEMPERATURES THERE. MANY MODELS AND STATISTICAL TOOLS
POINT TO AN INCREASED CHANCE FOR ABOVE-NORMAL TEMPERATURES ALONG THE WEST COAST
OF NORTH AMERICA AND MOST OF ALASKA. IN AREAS WHERE CLIMATE SIGNALS ARE WEAK
AND/OR NOT RELIABLE, EQUAL CHANCES (EC) OF BELOW-, NEAR- AND ABOVE-NORMAL MEAN
MONTHLY TEMPERATURES ARE INDICATED.

THE NMME, IMME AND CFS, FAVOR BELOW-MEDIAN PRECIPITATION IN THE PACIFIC
NORTHWEST AND ALSO THE ALASKA PANHANDLE. THE NMME FAVORS ABOVE-MEDIAN
PRECIPITATION AMOUNTS NEAR FLORIDA. COMPOSITES BASED ON YEARS WITH DEVELOPING
EL NINO CONDITIONS ALSO SUPPORT DRY TENDENCIES IN THE PACIFIC NORTHWEST, AND
TENDENCIES FOR WET CONDITIONS IN FLORIDA. ELSEWHERE, THE LACK OF CONSISTENT
SIGNALS AMONG TOOLS SUGGEST EQUAL CHANCES (EC) FOR BELOW- NEAR- OR ABOVE-MEDIAN
PRECIPITATION AMOUNTS. IT IS NOTEWORTHY THAT THE VARIOUS MODELS IN THE NMME
SHOW NO CONSISTENT SIGNAL FOR THE SOUTHERN HIGH PLAINS AND WEST TEXAS IN SPITE
OF VERY DRY INITIAL SOIL MOISTURE CONDITIONS IN SOME OF THESE REGIONS.

THE MAIN FACTORS THAT USUALLY INFLUENCE THE MONTHLY CLIMATE OUTLOOK INCLUDE:
1) EL NINO AND LA NINA - WHICH COMPRISE ENSO. IMPACTS OF THESE EVENTS ARE
SUMMARIZED BY SEPARATING 3-MONTH OBSERVATIONS FROM THREE OR MORE DECADES INTO
EL NINO, NEUTRAL AND LA NINA SETS, AVERAGING EACH SEPARATELY, AND THEN
COMPUTING ANOMALIES. THESE ARE CALLED "COMPOSITES" AND 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 - CALLED THE MADDEN JULIAN OSCILLATION
(MJO) - AFFECTS CLIMATE VARIABILITY WITHIN SEASONS.
4) THE ARCTIC OSCILLATION (AO), THE SIMILAR NORTH ATLANTIC OSCILLATION (NAO),
AND THE PACIFIC NORTH AMERICAN (PNA) PATTERNS - WHICH AFFECT THE TEMPERATURE
ANOMALY PATTERN ESPECIALLY DURING BOREAL WINTER AND ARE GENERALLY CONSIDERED TO
HAVE LOW PREDICTABILITY.
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 MODELS - CANONICAL CORRELATION ANALYSIS (CCA),
SCREENING MULTIPLE LINEAR REGRESSION (SMLR), CONSTRUCTED ANALOG (CA), AND
ENSEMBLE CCA (ECCA).
8) DYNAMICAL FORECAST MODELS - INCLUDING THE NCEP CLIMATE FORECAST SYSTEM
VERSION 2 (CFS) AND FOR THE ZERO-LEAD UPDATE FORECASTS THE NCEP GLOBAL ENSEMBLE
FORECAST SYSTEM (GEFS).  AN EXPERIMENTAL FORECAST SYSTEM, THE NATIONAL
MULTI-MODEL ENSEMBLE (NMME), COMPRISED OF SEVERAL DYNAMICAL MODELS IS ALSO USED.


FORECASTER: DAVID UNGER


THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING
THE WORLD METEOROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3
COMPLETE DECADES AS THE CLIMATE 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.



AN UPDATED MONTHLY OUTLOOK... FOR MAY WILL BE ISSUED ON WED APRIL 30 2014


THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD.

$$

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