PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
830 AM EST SUN DEC 31 2006

30-DAY OUTLOOK DISCUSSION FOR JANUARY 2007 - REVISED

BELOW AT THE BOTTOM IS THE OLD PMD FOR JANUARY 2007 AS OF THE MIDDLE OF
DECEMBER. WITH THE BENEFIT OF SHORT RANGE TOOLS BEING AVAILABLE AT THE END OF 
DECEMBER WE CAN NOW ADD THE FOLLOWING. AS FAR AS TEMPERATURE IS CONCERNED THERE
IS GOOD AGREEMENT BETWEEN THE LONG-LEAD FORECAST FOR JANUARY AND THE SHORT TERM
TOOLS - A CONSIDERATION THAT BOOSTS THE PROBABILITIES OF THE OUTCOME VERIFYING 
CATEGORICALLY. THE SHORT TERM TEMPERATURE FORECASTS ARE ALSO CONSISTENT WITH 
THE PATTERN THAT HAS BEEN IN PLACE IN THE LAST 2 OR 3 WEEKS IN DECEMBER WHICH 
RESEMBLES AN ENSO TEMPERATURE COMPOSITE. THE MODERATE WARM EVENT IN THE PACIFIC
IS AS MUCH IN PLACE NOW AS IT WAS 2 WEEKS AGO. IN GENERAL WE THUS INCREASED 
PROBABILITIES. 

THE PRECIPITATION FORECAST FOR JANUARY IS MUCH MORE PROBLEMATIC. THE LONG LEAD 
PRECIPITATION FORECAST WAS BASED ALMOST EXCLUSIVELY ON A WARM EVENT COMPOSITE 
I.E. WET ACROSS THE SOUTH. HOWEVER - NONE OF THE OFFICIAL LONG LEAD TOOLS 
SHOWED THIS PATTERN. FOR INSTANCE - WHILE THE CFS SHOWS AN ENSO EXPECTED 
TEMPERATURE FIELD OVER THE US IT DOES NOT PRODUCE AN ENSO EXPECTED 
PRECIPITATION PATTERN. WELL - NEITHER HAS NATURE AND THE SHORT TERM INDICATIONS
DON'T LOOK PARTICULARLY ENSO-ISH EITHER. WE THUS LOWERED PROBABILITIES OVER 
MUCH OF THE COUNTRY EXCEPT IN THE SOUTHEAST WHERE THE ENSO EXPECTED RAINS HAVE 
BEEN IN PLACE AND APPEAR TO CONTINUE INTO THE NEW YEAR. THERE ARE NO AREAS WITH
SIGNIFICANT PRECIPITATION DURING THE VERY EARLY PART OF JANUARY THAT WOULD 
PERMIT THE USE OF ABOVE MEDIAN FOR THE ENTIRE MONTH. THE AREA FOR BELOW MEDIAN 
IN THE OHIO VALLEY  WAS REMOVED BECAUSE THE 6-10 AND WEEK2 FORECASTS ARE ABOVE 
MEDIAN.

PMD AS DEC 21 FOLLOWS:

THE SST ANOMALIES ALONG THE EQUATOR IN THE CENTRAL AND EASTERN PACIFIC OCEAN 
ARE MORE THAN 1 DEGREE C ABOVE NORMAL FROM ABOUT 170E TO THE SOUTH AMERICAN 
COAST... WITH ANOMALIES OF MORE THAN 1.5 DEGREES C IN SOME PLACES. THE SST 
ANOMALIES HAVE INCREASED SLIGHTLY SINCE MID-NOVEMBER IN THE CENTRAL PACIFIC 
ENSO REGIONS INDICATING A STRENGTHENING OF EL NINO CONDITIONS.

THE FORECAST FOR T AND P FOR JANUARY 2007 IS BASICALLY AN ENSO COMPOSITE, WITH 
SOME ADJUSTMENT FOR RECENT INTERDECADAL TRENDS AS FOUND IN CCA OCN AND SMLR. 
CFS PREDICTIONS FOR THE US DURING JANUARY 2007 ARE QUITE WEAK.     

EL NINO IS NORMALLY ASSOCIATED WITH WARM TEMPERATURES IN THE NORTHERN GREAT 
PLAINS AND THE WESTERN GREAT LAKES REGION AND WETTER THAN MEDIAN CONDITIONS 
ACROSS THE SOUTH, ESPECIALLY IN TEXAS AND THE FLORIDA PENNINSULA. THE 
PROBABILITIES FOR A ONE MONTH MEAN ARE MORE MODEST THAN THEY WOULD BE FOR A 
SEASON BUT THE PATTERN IS VERY SIMILAR. 

EL NINO IMPACTS ON ALASKA ARE NOTED FOR TEMPERATURE - ESPECIALLY IN THE 
PANHANDLE. ON THE OTHER HAND THE IMPACT ON PRECIPITATION IS WEAK AND OR 
SCATTERED.

 

FORECASTER: HUUG VAN DEN DOOL

NOTES - AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL 
PROBABILITIES) ARE NOW LABELED EC (EQUAL CHANCES).

AN UPDATED MONTHLY OUTLOOK... FOR JANUARY 2007... WILL BE ISSUED ON SUN DEC 31 
2006

THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD.

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