PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
CLIMATE PREDICTION CENTER NCEP
NATIONAL WEATHER SERVICE  WASHINGTON D.C.
3 PM EST THURSDAY DEC 13 2001

30-DAY OUTLOOK DISCUSSION FOR JANUARY 2002
                                                                          .
  
EQUATORIAL PACIFIC SSTS REMAIN ABOUT .5 TO 1.0 DEGREES C BELOW NORMAL FROM 
ABOUT 160W TO THE SOUTH AMERICAN COAST.  WARMER THAN NORMAL SSTS 
PREDOMINATE THROUGHOUT MUCH OF THE TROPICAL PACIFIC WEST OF THE DATE LINE.  
THE EQUATORIAL PACIFIC WHEN TAKEN AS A WHOLE REMAINS IN A NEUTRAL ENSO 
STATE THIS MONTH - AND IS EXPECTED TO STAY THAT WAY THROUGH THE MONTH OF 
JANUARY.  HOWEVER - THERE IS A STRONG CONSENSUS AMONG BOTH NUMERICAL MODELS 
AND STATISTICAL PREDICTION TOOLS THAT THE SST ANOMALIES IN THE EQUATORIAL 
PACIFIC - COLD IN THE EAST AND WARM IN THE WEST - WILL INFLUENCE THE 
FORECAST IN THE U.S. - ESPECIALLY FOR PRECIPITATION IN THE SOUTHERN U.S.

ALL TOOLS INDICATE BELOW MEDIAN PRECIPITATION IN THE FLORIDA PENNINSULA.  
THERE IS BROAD AGREEMENT AMONG NUMERICAL MODELS FOR BELOW MEDIAN PRECIPITA-
TION IN CALIFORNIA AND WESTERN NEVADA.  STATISTICAL TOOLS ALSO INDICATE 
BELOW MEDIAN PRECIPITATION IN THE SOUTHWESTERN U.S. BUT CENTER THE AREA IN 
ARIZONA AND NEW MEXICO.  THERE ARE SOME SIGNALS FOR ABOVE MEDIAN PRECIPITA-
TION IN TEXAS AND THE SOUTHERN PLAINS - BUT THEY ARE TOO WEAK TO OVERCOME 
THE LARGE AMOUNT OF VARIABILITY WITHIN A SINGLE MONTH.  THERE ARE NO 
SYSTEMATIC INDICATIONS AMONG THE VARIOUS TOOLS FOR PRECIPITATION SIGNALS 
ELSEWHERE.  

RECENT TRENDS INDICATE ABOVE NORMAL TEMPERATURES IN THE SOUTHERN U.S. - 
EXCEPT ALONG IMMEDIATE COASTAL AREAS IN THE WEST WHERE COOLER-THAN-NORMAL 
SSTS WILL HAVE A MODERATING EFFECT.  ENSEMBLE PREDICTION FROM MANY 
DIFFERENT NUMERICAL MODELS - BOTH RUN AT NCEP AND AT OTHER CENTERS FOR 
CLIMATE PREDICTION - SHOW A LARGE VARIABILITY IN THEIR TEMPERATURE FORECAST 
FOR OF MOST OF NORTH AMERICA.  THE NUMERICAL MODELS SLIGHTLY FAVOR COLDER-
THAN-NORMAL TEMPERATURES IN THE EASTERN U.S. - WHICH IS CONSISTENT WITH 
NEUTRAL ENSO COMPOSITES AND IS SUPPORTED IN NEW ENGLAND BY SMLR FORECASTS.  
THIS SIGNAL IS STRONG ENOUGH TO OVERCOME RECENT WARMING TRENDS TO SLIGHTLY 
FAVOR BELOW NORMAL TEMPERATURES FOR THE NORTHEAST IN JANUARY.  THE LARGE 
AMOUNT OF VARIABILITY PREDICTED BY THE MODELS SHOULD OVERWHELM RECENT 
TRENDS TOWARD WARMER-THAN-NORMAL WINTERS ELSEWHERE IN THE U.S. AND BRING 
EXPECTED TEMPERATURES INTO LINE WITH THE 1971-2000 CLIMATOLOGY.  
 

FORECASTER: D. UNGER
  
NOTE - THIS CLIMATE OUTLOOK IS INTENDED FOR USE ONLY PRIOR TO THE START
OF THE VALID PERIOD.  WITHIN THE VALID PERIOD OBSERVATIONS AND SHORT
AND MEDIUM RANGE FORECASTS SHOULD BE CONSULTED.
  
NOTE - THE NEXT 0.5 MONTH LEAD-TIME MONTHLY OUTLOOK WILL BE ISSUED THURSDAY 
JANUARY 17 2002.
  
NOTE - THE NEW 1971-2000 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE 
WITH THE MAY 17 2001 FORECAST RELEASE.