PROGNOSTIC DISCUSSION FOR LONG-LEAD OUTLOOKS
CLIMATE PREDICTION CENTER NCEP
NATIONAL WEATHER SERVICE  WASHINGTON DC
3 PM EST THURSDAY FEBRUARY 14 2002

     BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOK
         .         .         .         .         .         .         .         .
THIS OUTLOOK REFLECTS THE EXPECTED U.S. CLIMATE ANOMALIES BASED ON THE LONG-
TERM TREND AS ESTIMATED BY OCN - AND STATISTICALLY BASED RELATIONSHIPS BETWEEN 
RECENT OCEANIC AND ATMOSPHERIC CONDITIONS AND U.S. TEMPERATURE AND PRECIP-
ITATION.  DYNAMICAL FORECASTS FROM GENERAL CIRCULATION MODELS WERE ALSO USED 
FOR THE FIRST FOUR SEASONS.  THE EXPECTED TRANSITION TO EL NINO CONDITIONS 
INFLUENCES THE OUTLOOK BEGINNING WITH THE JAS 2002 FORECAST.  THE OUTLOOK FOR 
OND 2002 AND BEYOND ARE HEAVILY INFLUENCED BY THE ANTICIPATION OF AN EL NINO 
EVENT FOR NEXT WINTER. 

 
     CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS

PACIFIC SSTS ARE NOW ABOUT 1 DEG C ABOVE NORMAL ALONG THE EQUATOR FROM JUST 
WEST OF THE INTERNATIONAL DATE LINE TO ABOUT 150 W.  TEMPERATURES NEAR THE 
SOUTH AMERICAN COAST ARE NEAR TO SLIGHTLY BELOW NORMAL.  SUB-SURFACE PACIFIC 
OCEAN TEMPERATURES ALONG THE EQUATOR ARE SUBSTANTIALLY WARMER THAN NORMAL - 
AND THEIR EVOLUTION SUGGESTS THAT A WARM EVENT MAY BE UNDERWAY.  THE DEPTH OF 
THE OCEANIC THERMOCLINE HAS INCREASED MARKEDLY IN THE EAST-CENTRAL PACIFIC IN 
RECENT WEEKS.  ATMOSPHERIC INDICIES - HOWEVER - CONTINUE TO REFLECT NEUTRAL 
ENSO CONDITIONS AND ARE DOMINATED BY MJO ACTIVITIY WHICH HAS BEEN VIGOROUS IN 
THE LAST FEW MONTHS.  THE EXTRATROPICAL NORTH PACIFIC SSTS CONTINUE TO BE 
BELOW NORMAL OVER A LARGE AREA EXTENDING FROM THE MID-PACIFIC EASTWARD TO THE 
NORTH AMERICAN COAST.  

       .         .         .         .         .         .         .         .
     PROGNOSTIC DISCUSSION OF SST FORECASTS

MOST STATISTICAL AND DYNAMICAL PREDICTIONS OF NINO 3.4 SSTS INDICATE A GRADUAL
WARMING FOR THE NEXT SEVERAL MONTHS.  TWO OF THE THREE MAIN TOOLS RUN AT NCEP 
FORECAST WEAK TO MODERATE WARM EPISODE (EL NINO) CONDITIONS TO DEVELOP BY 
SUMMER (CCA AND THE NCEP NUMERICAL MODEL) - WHILE THE CONSTRUCTED ANALOG (CA) 
METHOD KEEPS TEMPERATURES NEAR NORMAL THROUGH THE REMAINDER OF 2002.  THE CA 
PREDICTION DOES NOT ACCOUNT FOR THE SUB-SURFACE OBSERVATIONS WHICH HAVE 
CHANGED DRAMATICALLY IN THE LAST FEW MONTH - WHICH MAY EXPLAIN ITS LACK OF 
RESPONSE TO RECENT CHANGES.  THE MOST RECENT OBSERVATIONS OF SSTS IN THE 
CENTRAL PACIFIC - ALONG WITH THE SUB SURFACE STRUCTURE SUPPORTS THE ENSO 
PREDICTION TOOLS THAT FAVOR WARMER SSTS - HENCE THE OFFICIAL FORECAST IS FOR A
WARM ENSO EVENT TO DEVELOP WITHIN THE NEXT FEW MONTHS.  THUS THIS MONTH 
OUTLOOK WILL FOLLOW THE FORECAST FROM THE NCEP MODEL AND CCA AND NOT THE CA OR 
THE REGRESSION CONSOLIDATION FORECAST.  ABOVE NORMAL CENTRAL EQUATORIAL 
PACIFIC SSTS ARE ALSO SUPPORTED BY MANY MODELS RUN AT OTHER CLIMATE CENTERS AS 
WELL AS THE CPC MARKOV STATISTICAL MODEL.    

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

THE STATISTICAL TOOLS ... CCA - OCN - SMLR ... WERE CONSULTED AT ALL LEAD
TIMES.  DYNAMICAL MODEL FORECASTS FROM NCEP AND OTHER FORECAST CENTERS WERE 
CONSULTED FOR THE PERIOD MAM - JJA 2002.  THE LARGE SCALE CIRCULATION PATTERNS 
ARE ANTICIPATED TO REFLECT WARM ENSO CONDITIONS BY LATE SUMMER AND INTO THE
NEXT COOL SEASON - SO WARM EVENT COMPOSITES WERE CONSULTED FOR SEASONS PAST
JAS 2002.  


         .         .         .         .         .         .         .         .
     PROGNOSTIC DISCUSSION OF OUTLOOKS - MAM 2002 TO FMA 2003

TEMPERATURE:

THERE IS A GENERAL CONSENSUS FOR ABOVE NORMAL TEMPERATURES ACROSS MUCH OF THE 
WESTERN U.S. AMONG THE DYNAMICAL MODELS AND THE STATISTICAL TOOLS DURING MAM 
AND AMJ 2002.  THE NCEP MODEL CONTINUES TO PREDICT BELOW NORMAL TEMPERATURES 
OVER MUCH OF THE U.S. - AS IT HAS FOR THE PAST FEW SEASONS - AND WILL BE 
DISCOUNTED BECAUSE IT WAS NOT CONSISTENT WITH THE SOLUTIONS FROM NUMERICAL 
MODELS RUN AT OTHER CENTERS AND CONFLICTED WITH THE FORECASTS FROM THE 
STATISTICAL TOOLS.  CCA INDICATES TEMPERATURES IN THE WEST WILL BE BELOW THE 
MEAN OF THE LAST DECADE - BUT SINCE THERE IS A STRONG WARMING TREND THERE - 
ABOVE NORMAL TEMPERATURES ARE STILL SLIGHTLY FAVORED.  DRY INITIAL SOIL 
MOISTURE CONDITIONS AND LOW SNOW COVER ARE A REAL CONCERN IN THE NATIONS MID-
SECTION - BECAUSE IT WILL RESULT IN ANOMALOUSLY HIGH PORTION OF SOLAR ENERGY 
BEING CONVERTED TO SURFACE HEATING INSTEAD OF FOR EVAPORATION.  THUS ABOVE 
NORMAL TEMPERATURES HAVE BEEN EXTENDED FURTHER EASTWARD THAN IN LAST MONTHS 
MAM FORECAST.  BELOW NORMAL SSTS IN THE EASTERN NORTH PACIFIC WILL COUNTERACT 
THE RECENT WARMING TRENDS ALONG THE WEST COAST FROM ALASKA TO CALIFORNIA AND 
ARE ANTICIPATED TO BRING CONDITIONS THERE MORE IN LINE WITH THE 1971-2000 
CLIMATOLOGY THAN TRENDS INDICATE.  CCA PREDICTS BELOW NORMAL TEMPERATURES FOR
INTERIOR ALASKA FOR MAM - MJJ WHICH CONFLICTS WITH RECENT TRENDS THERE - 
SUGGESTING THE ALASKAN TEMPERATURES WILL REFLECT THE LONG TERM NORMALS - AND 
HAVE BEEN REDUCED FROM TEMPERATURES PREDICTED ON LAST MONTHS OUTLOOK.  

ONLY MINOR CHANGES WERE MADE FROM THE PREVIOUS SET OF FORECASTS BEYOND THE 
SPRING.  THE AREA OF ABOVE NORMAL TEMPERATURES FORECAST FOR JJA 2003 WAS 
EXPANDED SLIGHTLY IN THE EASTERN U.S. DUE TO SIGNALS FROM CCA - OCN AND SMLR.
CCA - OCN - AND SMLR INDICATE WARMER-THAN-NORMAL TEMPERATURES FOR MOST 
SEASONS FROM MAM 2002 THROUGH MAM 2003 IN THE SOUTHWEST U.S.

TEMPERATURES FOR OND 2002 THROUGH MAM 2003 REFLECT THE INFLUENCE OF TRENDS AND 
AN ANTICIPATED MATURE EL NINO EVENT.  PROBABILITY ANOMALIES ARE MODEST SINCE 
THE STRENGTH OF THE WARM EVENT IS UNCERTAIN AT THIS TIME.  IN THE ABSENCE OF 
TRENDS - THE WINTERTIME TEMPERATURES THROUGHOUT MUCH OF THE SOUTHERN U.S. TEND 
TO BE BELOW NORMAL IN A WARM ENSO EVENT - HOWEVER - WITH A STRONG WARMING 
TREND IN THE WEST - THE TEMPERATURES THERE WILL STILL SLIGHTLY FAVOR THE ABOVE
NORMAL CATEGORY.  TEMPERATURE TRENDS ARE WEAKER IN THE SOUTHEASTERN U.S. THAN 
IN THE WEST AND THE ENSO SIGNAL FOR BELOW NORMAL IS STRONG ENOUGH TO FAVOR 
BELOW NORMAL TEMPERATURES OVER FLORIDA NEXT WINTER AND SPRING.  A WARM EVENT 
IS ASSOCIATED WITH NEAR TO BELOW NORMAL TEMPERATURES ALONG THE GULF COAST AND 
TEXAS - HOWEVER UNCERTAINTY IN THE STRENGTH OF THE WARM EVENT PREVENTS A CLEAR 
DETERMINATION OF THE CATEGORICAL FORECAST THERE - LEAVING THE ODDS CLOSE TO 
CLIMATOLOGY.  

.        .         .         .         .         .         .         .         .
PRECIPITATION:

SMLR AND CCA AND MOST NUMERICAL MODELS CONTINUE TO PREDICT BELOW MEDIAN PRECIP-
ITATION IN THE SOUTHWEST U.S. FOR MAM 2002 RESULTING IN A MODEST INCREASE OF 
THE ODDS TOWARD BELOW MEDIAN PRECIPITATION THERE.  THE NUMERICAL MODELS RUN AT 
NCEP AND OTHER FORECAST CENTERS FAVOR BELOW MEDIAN PRECIPITATION OVER MUCH OF 
THE SOUTHWESTERN U.S. - AS WELL AS FOR TEXAS AND FLORIDA.  HOWEVER - THE 
PREDICTION OF DRY CONDITIONS IN THOSE REGIONS IN SPRINGTIME REQUIRES A STRONG 
CLIMATE SIGNAL SINCE THE SEASONAL TOTAL PRECIPITATION COME FROM ONLY A FEW 
PRECIPITATION EVENTS - SO CLIMATOLOGICAL ODDS ARE GIVEN.  ABOVE MEDIAN 
PRECIPITATION IS FAVORED IN THE PACIFIC NORTHWEST IN AMJ AND MJJ DUE TO LONG-
TERM TRENDS.  WARM ENSO CONDITIONS TEND TO INHIBIT THE SOUTHWEST MONSOON - SO 
THE TREND-RELATED AREA OF BELOW MEDIAN PRECIPITATION WAS EXPANDED SLIGHTLY TO 
INCLUDE PORTIONS OF THE SOUTHWEST U.S..  A WET AREA FORECAST OVER FLORIDA 
DURING LATE SUMMER AND EARLY FALL IS THE RESULT OF OCN INDICATIONS. 

WARM ENSO CONDITIONS ARE NOW EXPECTED TO APPEAR EARLIER THAN THEY WERE A MONTH 
AGO SO SOME LATE SUMMER AND FALL ENSO SIGNALS HAVE BEEN ADDED TO THE CURRENT 
OUTLOOK.  THESE INCLUDE A PREDICTION OF DRY CONDITION FOR PORTIONS OF THE MID-
ATLANTIC STATES IN ASO AND SON 2003 - AND BELOW MEDIAN PRECIPITATION ALONG THE
COAST IN THE PACIFIC NORTHWEST IN SON AND OND.  BEGINNING IN OND 2002 AND 
CONTINUING THROUGH MAM 2003 EXTENSIVE AREAS OF ABOVE MEDIAN PRECIPITATION WITH 
MODEST PROBABILITIES ARE FORECAST ACROSS THE SOUTHERN PART OF THE NATION DUE 
TO EXPECTED EL NINO CONDITIONS.  FORECAST DRYNESS CENTERED OVER THE NORTHERN 
ROCKIES IS FROM BOTH OCN AND EL NINO COMPOSITES.  THE BELOW MEDIAN PRECIP-
ITATION IN THE NORTH CENTRAL STATES AND THE OHIO VALLEY FROM JFM 2003 THROUGH 
MAM 2003 ARE ALSO DUE TO EXPECTED EL NINO INFLUENCES. 

THERE ARE NO RELIABLE FORECAST INDICATIONS FOR ALASKA PRECIPITATION TO DEPART 
FROM CLIMATOLOGICAL PROBABILITIES DURING ANY OF THE LEADS AT THIS TIME. 

FORECASTERS:  D. UNGER AND R. MARTIN
  
FOR A DESCRIPTION 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/MULTI-SEASON/
13_SEASONAL_OUTLOOKS/TOOLS  (USE LOWER CASE LETTERS)

INFORMATION ON THE FORMULATION AND SKILL OF THE CAS FORECASTS MAY BE FOUND AT:
HTTP://WWW.CPC.NCEP.NOAA.GOV/SOILMST/FORECASTS.HTML  (USE LOWER CASE LETTERS)

NOTES - THESE CLIMATE OUTLOOKS ARE INTENDED FOR USE PRIOR TO THE START OF
THEIR VALID PERIODS.  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 THURSDAY MARCH 14 2002.

1971-2000 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 17 2001
FORECAST RELEASE.

NNNN
NNNN