000
AXPZ20 KNHC 230323
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED DEC 23 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N80W 6N87W 3N102W 3N118W 8N130W 
8N131W 9N140W. NO SIGNIFICANT CONVECTION IS NOTED.

...DISCUSSION...

LONGWAVE TROUGH W OF THE AREA APPROACHING 144W WILL CONTINUE 
EASTWARD EXPECTED TO MOVE INTO THE WESTERN PORTION OF THE AREA 
WITHIN THE NEXT 24 HRS. A SMALL CYCLONIC CIRCULATION E OF THE 
TROUGH HAS PULLED NNE IS PRESENTLY JUST NW OF THE AREA NEAR 
31N138W. E OF THE AREA OVER THE DISCUSSION AREA...BROAD 
MID/UPPER ANTICYCLONIC FLOW IS RATHER PRONOUNCED WITH A MEAN 
RIDGE AXIS EXTENDING FROM 30N128W TO 20N124W TO 15N122W TO NEAR 
8N118W. A JET STREAM BRANCH ENTERS THE AREA AHEAD OF THE TROUGH 
THROUGH 22N140W...AND EXTENDS NE  29N131W THEN CONTINUES E 
TOWARDS CENTRAL BAJA CALIFORNIA. STRONG SW TO W WINDS WITH 
MAXIMUM JET CORE SPEEDS OF 60-90 KT ARE NOTED BY SATELLITE 
DERIVED WINDS OVER THE AREA FROM 23N TO 27N BETWEEN 120W AND 
131W. OVER THE FAR NE PORTION...A STRONG SHORTWAVE TROUGH HAS 
JUST ABOUT MOVED INLAND SOUTHERN CALIFORNIA WITH FAST WLY FLOW 
FOLLOWING BEHIND IT. THE ASSOCIATED SURFACE COLD FRONT EXTENDS 
FROM FAR NW MEXICO SW TO CENTRAL BAJA CALIFORNIA NEAR 28N114W 
AND TO NEAR 26N117W WHERE IT BECOMES RATHER DIFFUSE. A PLUME OF 
MOSTLY MID AND UPPER LEVEL MOISTURE EMANATING FROM THE DEEP 
TROPICS AHEAD OF THE LONGWAVE TROUGH CONSISTS OF BROKEN TO 
OVERCAST MID AND HIGH CLOUDS FROM 10N TO 30N BETWEEN 123W AND 
139W...AND WITHIN 150 NM EITHER SIDE OF A LINE FROM 24N123W TO 
25N117W TO ACROSS CENTRAL BAJA CALIFORNIA AND FURTHER E TO 
ACROSS NORTHERN MEXICO OF THE TROUGH. WIDELY SCATTERED SHOWERS 
AND ISOLATED TSTMS ARE POSSIBLE FROM 11N TO 22N W OF 133W.

ELSEWHERE AT THE SURFACE...A WEAK AND PERSISTENT WEAK 1011 MB 
LOW DRIFTING W IS NEAR 14N124W. AN AREA OF NE TO E 20 KT TRADE 
WINDS INDUCED BY A TIGHTENING OF THE PRES GRADIENT BETWEEN 
SURFACE HIGH PRES TO THE N AND NW OF THE LOW IS LOCATED FROM 13N 
TO 23N W OF 128W. WITH THE LOW WEAKENING FURTHER AND HIGH PRES 
TO THE N ALSO WEAKENING WHILE MOVING E IN ADVANCE OF AN 
APPROACHING STRONGER COLD FRONT TOWARDS THE NW PORTION OF THE 
AREA...THIS AREA OF WINDS WILL DIMINISH CONSIDERABLY THROUGH THE 
NEXT 48 HRS...BUT SEAS UP 11 FT IN LARGE NW SWELLS WILL BE 
POSSIBLE OVER THE FAR W AND NW PARTS BY THU. WEAK TROUGHS MOVING
W 10 KT WERE ANALYZED ALONG 121W FROM 9N TO 12N...AND ALONG 135W 
FROM 9N TO 15N.

THE SOUTHERN PORTION OF A RATHER SHARP MID/UPPER LEVEL TROUGH 
EXTENDS FROM FAR WESTERN CARIBBEAN SEA SSW TO ACROSS CENTRAL
AMERICA...AND REACHES TO 8N93W TO NEAR 1N96W. THE UPPER FLOW 
PATTERN BETWEEN THE TROUGH AND THE WESTERN EXTENSION OF 
MID/UPPER LEVEL RIDGING THAT EXTENDS OVER S AMERICA ALONG 8N IS 
ADVECTING UPPER LEVEL ITCZ MOISTURE NORTHWARD ACROSS PANAMA FROM 
N OF 5N. SATELLITE WATER VAPOR IMAGERY SHOWED ABUNDANT MODERATE 
SUBSIDENCE INDICATIVE OF DRY SINKING AIR AND VERY STABLE 
CONDITIONS COVERING JUST ABOUT THE ENTIRE AREA S AND SE OF THE 
ABOVE MENTIONED PLUME OF CLOUDS.

A SMALL AREA OF N WINDS TO 20 KT OVER THE FAR NORTHERN PORTION 
OF THE GULF OF TEHUANTEPEC WILL SUBSIDE SHORTLY AS GRADIENT ALONG
THE COAST WEAKENS.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE
  
$$
AGUIRRE