FXUS24 KWNC 051500
PMDENS
EL NINO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
1000 AM EST THU 05 NOV 2009
 
 
NOTE: FIGURES MENTIONED IN THE DISCUSSION ARE AVAILABLE
ON THE INTERNET AT HTTP://WWW.CPC.NCEP.NOAA.GOV
 
EL NINO/SOUTHERN OSCILLATION /ENSO/ DIAGNOSTIC DISCUSSION
ISSUED BY CLIMATE PREDICTION CENTER/NCEP/NWS 5 NOVEMBER 2009
ENSO ALERT SYSTEM STATUS: EL NINO ADVISORY
SYNOPSIS:  EL NINO IS EXPECTED TO CONTINUE STRENGTHENING AND
LAST THROUGH AT LEAST THE NORTHERN HEMISPHERE WINTER 2009-2010.
DURING OCTOBER 2009, SEA SURFACE TEMPERATURE /SST/ ANOMALIES
INCREASED ACROSS THE CENTRAL AND EASTERN EQUATORIAL PACIFIC
OCEAN.  THE NINO-3.4 INDEX INCREASED NEARLY A DEGREE WITH THE
MOST RECENT WEEKLY VALUE AT +1.5C.  ABOVE-AVERAGE SUBSURFACE
TEMPERATURE ANOMALIES INCREASED ACROSS A LARGE REGION OF
THE CENTRAL AND EAST-CENTRAL PACIFIC, WITH ANOMALIES RANGING
BETWEEN +1 TO +5C BY THE END OF THE MONTH.  CONSISTENT WITH
THIS WARMING, SUBSURFACE OCEANIC HEAT CONTENT ANOMALIES
/AVERAGE DEPARTURES IN THE UPPER 300M OF THE OCEAN/ ALSO
INCREASED DURING THE MONTH.  IN ADDITION, LOW-LEVEL WESTERLY
AND UPPER-LEVEL EASTERLY WIND ANOMALIES STRENGTHENED OVER MUCH
OF THE EQUATORIAL PACIFIC.  THE PATTERN OF TROPICAL CONVECTION
ALSO REMAINED CONSISTENT WITH EL NINO, WITH ENHANCED CONVECTION
OVER THE WEST-CENTRAL PACIFIC AND SUPPRESSED CONVECTION OVER
INDONESIA. COLLECTIVELY, THESE OCEANIC AND ATMOSPHERIC ANOMALIES
REFLECT A STRENGTHENING EL NINO.
THERE CONTINUES TO BE DISAGREEMENT AMONG THE MODELS ON THE
EVENTUAL STRENGTH OF EL NINO, BUT THE MAJORITY INDICATE THAT
THE THREE-MONTH AVERAGE NINO-3.4 SST INDEX VALUE WILL RANGE
BETWEEN +1.0C AND +1.5C DURING THE NORTHERN HEMISPHERE WINTER.
CONSISTENT WITH THE HISTORICAL EVOLUTION OF EL NINO, A PEAK IN
SST ANOMALIES IS EXPECTED SOMETIME DURING NOVEMBER-JANUARY.
AT THIS TIME, THERE IS A HIGH DEGREE OF UNCERTAINTY OVER HOW
LONG THIS EVENT WILL PERSIST. MOST OF THE MODELS SUGGEST THAT
THIS EVENT WILL LAST THROUGH MARCH-MAY 2010, ALTHOUGH THE MOST
LIKELY OUTCOME IS THAT EL NINO WILL PEAK AT LEAST AT MODERATE
STRENGTH /3-MONTH NINO-3.4 SST INDEX OF +1.0C OR GREATER/ AND
LAST THROUGH AT LEAST THE NORTHERN HEMISPHERE WINTER 2009-10.
EXPECTED EL NINO IMPACTS DURING NOVEMBER 2009-JANUARY 2010
INCLUDE ENHANCED PRECIPITATION OVER THE CENTRAL TROPICAL PACIFIC
OCEAN AND A CONTINUATION OF DRIER-THAN-AVERAGE CONDITIONS OVER
INDONESIA.  FOR THE CONTIGUOUS UNITED STATES, POTENTIAL IMPACTS
INCLUDE ABOVE-AVERAGE PRECIPITATION FOR FLORIDA, CENTRAL AND
EASTERN TEXAS, AND CALIFORNIA, WITH BELOW-AVERAGE PRECIPITATION
FOR PARTS OF THE PACIFIC NORTHWEST.  ABOVE-AVERAGE TEMPERATURES
AND BELOW-AVERAGE SNOWFALL IS MOST LIKELY FOR THE NORTHERN
ROCKIES, NORTHERN PLAINS, AND UPPER MIDWEST, WHILE BELOW-AVERAGE
TEMPERATURES ARE EXPECTED FOR THE SOUTHEASTERN STATES.
 
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