000
AXPZ20 KNHC 092205
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI DEC 9 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 07N94W WHERE LOW LEVEL 
WINDS SUGGEST THAT THE ITCZ BEGINS AND EXTENDS TO 07N106W TO 
08N120W TO 10N131W TO 09N140W. NUMEROUS MODERATE TO STRONG 
CONVECTION EXISTS FROM 08N TO 14N BETWEEN 132W AND 138W.

...DISCUSSION...

IN THE UPPER LEVELS...A SHARP TROUGH JUST WEST OF OUR AREA 
EXTENDING FROM 22N146W SE INTO THE FAR WESTERN PORTION OF THE
AREA NEAR 05N138W IS PROVIDING LIFT FOR THE AFOREMENTIONED 
CONVECTION NEAR THE ITCZ IN THE WESTERN PORTION OF THE ITCZ.  
SOME CONTINUED DEEP CONVECTION SHOULD BE EXPECTED AS THE UPPER 
TROUGH AND ITCZ INTERACT DURING THE NEXT TWO DAYS WITH LITTLE
CHANCE OF LOW PRES DEVELOPMENT DUE TO STRONG VERTICAL SHEAR AND 
LACK OF A SIGNIFICANT SURFACE DISTURBANCE.  ELSEWHERE...THE 
TROPICAL NE PACIFIC IS DOMINATED BY A LARGE ANTICYCLONE CENTERED 
NEAR 14N111W...WHICH IS PROMOTING TYPICALLY SUBSIDENT AND DRY 
CONDITIONS AS WELL AS ADVECTING SOME OF THE UPPER LEVEL MOISTURE 
AND CLOUDINESS FROM THAT CONVECTION TOWARD NW MEXICO.

AT THE SURFACE...A 1024 MB HIGH CENTER NEAR 31N126W EXTENDS
A RIDGE SSW TO 16N128W. THE COMBINATION OF THE RIDGE WITH 
ITCZ ASSOCIATED LOW PRESSURE IS ALLOWING FOR NE TO E WINDS OF
20 TO 25 KT TO OCCUR FROM 08N TO 22N W OF 125W. HIGHER WINDS
OF 20 TO 20 KT ARE EVIDENT WITHIN THE DEEP CONVECTION DESCRIBED
ABOVE UNDER ITCZ FROM 10N TO 12N BETWEEN 134W AND 137W. SEAS
WITHIN THIS AREA OF WINDS ARE IN THE 8 TO 11 FT RANGE. WITH 
THE GRADIENT NOT EXPECTED TO VARY MUCH OVER THE NEXT COUPLE OF
DAYS...EXPECTED LITTLE CHANGES WITH THESE WINDS THROUGH THAT
TIME.

AFTER DIMINISHING TO LESS THAN GALE FORCE THIS MORNING AS 
SUGGESTED BY AN ASCAT PASS FROM THIS AFTERNOON...WINDS THROUGH
THE GULF OF TEHUANTEPEC ARE FORECAST TO AGAIN PERK UP TO GALE
FORCE SAT MORNING AS THE LOCAL SURFACE PRESSURE GRADIENT OVER
AND JUST INLAND THE GULF OF TEHUANTEPEC AGAIN TIGHTENS. BASED
ON LATEST MODEL GUIDANCE...IT APPEARS THIS NEXT EVENT WILL LAST
THROUGH THE NEXT FEW DAYS.

BOTH THE GULF OF CALIFORNIA AND THE GULF OF PAPAGAYO MAY BRIEFLY 
EXPERIENCE 20 KT SURFACE WINDS.  BUT SINCE THESE ARE NOT 
EXPECTED TO BE OF MORE THAN SIX HOUR DURATION NOR OF LARGE 
SPATIAL EXTENT...THESE ARE NOT INCLUDED IN THE HIGH SEAS 
FORECAST.

LONG-PERIOD NW SWELL JUST ENTERING THE NW CORNER OF OUR AREA 
WILL SPREAD SOUTHEASTWARD DURING THE NEXT COUPLE OF DAYS TO 
COVER ABOUT HALF OF OUR AREA.  HOWEVER...THESE WILL ONLY BE OF 
UP TO 10 FEET SIGNIFICANT WAVE HEIGHT.

$$
AGUIRRE