932
FXUS07 KWBC 201330
PMD30D
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
830 AM EST THU NOV 20 2008
30-DAY OUTLOOK DISCUSSION FOR DECEMBER 2008
SEA SURFACE TEMPERATURES (SSTS) IN THE CENTRAL EQUATORIAL PACIFIC OCEAN ARE
NEAR LONG-TERM AVERAGE VALUES. SSTS IN THE NINO 3.4 REGION OF THE PACIFIC
(170W TO 120W AND 5N TO 5S) AVERAGED ABOUT .2 DEGREES C BELOW NORMAL IN THE
FIRST HALF OF NOVEMBER. ATMOSPHERIC CONDITIONS IN THE TROPICAL PACIFIC OCEAN
ARE CONSISTENT WITH ENSO-NEUTRAL CONDITIONS, WITH WIND AND CONVECTIVE PATTERNS
IN THE FEW WEEKS REFLECTIVE OF A WEAK MADDEN-JULIAN OSCILLATION (MJO). THE
MAJORITY OF SST PREDICTION MODELS PREDICT NINO 3.4 SSTS TO REMAIN SLIGHTLY
BELOW NORMAL THROUGH DECEMBER, BUT TO REMAIN WITHIN .5 C OF NORMAL, INDICATING
ENSO NEUTRAL CONDITIONS WILL CONTINUE THROUGH THE END OF THE YEAR. MJO
ACTIVITY IS EXPECTED TO REMAIN WEAK SO NO SIGNIFICANT PREDICTABLE IMPACTS ARE
EXPECTED AT THIS TIME FROM EITHER ENSO OR THE MJO.
THE TEMPERATURE OUTLOOK INDICATES ABOVE NORMAL TEMPERATURES FROM THE SOUTHERN
ROCKIES TO THE UPPER MISSISSIPPI VALLEY. THIS AREA IS SUPPORTED TO SOME EXTENT
BY CFS, CCA AND OCN FORECASTS, ALTHOUGH EXPECTED SKILL ON A 30-DAY PERIOD IS
QUITE LOW, SO THE SLIGHTLY ENHANCED CHANCES OF ABOVE NORMAL TEMPERATURES MOSTLY
REFLECT MORE CONFIDENT SIGNALS FROM THE DJF SEASONAL OUTLOOK. THE OCN TOOL
SUGGEST TRENDS FOR ABOVE NORMAL TEMPEARATURES IN CENTRAL AND NORTHERN ALASKA.
THE PRECIPITATION OUTLOOK CALLS FOR BELOW MEDIAN PRECIPITATION FOR THE SOUTHERN
U.S. FROM SOUTHERN NEW MEXICO TO THE SOUTHEASTERN STATES. THIS MAINLY REFLECTS
THE CFS FORECAST, ALTHOUGH THERE IS ADDITIONAL SUPPORT IMPLIED FROM THE DJF
FORECASTS FROM THE CCA, SMLR, OCN, CFS AND CLIMATE MODELS RUN AT OTHER CENTERS.
ABOVE MEDIAN PRECIPITATION IS INDICATED BY THE CFS FOR THE NORTHERN ROCKIES.
AN AREA OF ABOVE MEDIAN PRECIPITATION IS INDICATED FOR PARTS OF THE SOUTHERN
GREAT PLAINS FROM OCN AND SMLR FORECASTS.
FORECASTER: DAVID UNGER
NOTES: AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL
PROBABILITIES) ARE NOW LABELED AS EC (EQUAL CHANCES).
AN UPDATED MONTHLY OUTLOOK... FOR DEC WILL BE ISSUED ON SUN NOVEMBER 30 2008
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD.
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