000
AXPZ20 KNHC 090930
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

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

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 07N90W. ITCZ EXTENDS
FROM 07N90W TO 06N109W TO 10N127W TO 08N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION FROM 08N TO 15N W OF 138W.

...DISCUSSION...

OMEGA BLOCK UPPER LEVEL PATTERN EVIDENT ON WATER VAPOR IMAGERY N 
OF 30N. AN UPPER LEVEL TROUGH IS LOCATED W OF THE REGION ALONG 
150W. DIFFLUENT MOIST SW MID-UPPER LEVEL FLOW ROUNDS THE BASE OF 
THIS TROUGH AND COVERS A BROAD ZONE NORTH OF THE ITCZ AXIS N OF 
07N W OF 120W...PROVIDING A VERY FAVORABLE ENVIRONMENT FOR DEEP 
CONVECTION W OF 135W.

THE BROAD SCALE PATTERN WILL NOT CHANGE SIGNIFICANTLY THROUGH THE
NEXT 24-48 HOURS. BROAD MERIDIONAL RIDGING FROM THE DEEP TROPICS 
TO N OF 30N WILL CONTINUE TO DEFLECT SHORTWAVE TROUGHS NORTHWARD 
AWAY FROM THE AREA...WITH NO FRONTS EXPECTED TO CROSS S OF 32N.

ASCAT PASS AT 0400 UTC AND WINDSAT PASS AT 0000 UTC BOTH SHOWED 
WINDS IN THE GULF OF TEHUANTEPEC AROUND 25 KT...SO HAVE DROPPED 
GALE WARNING FOR NOW. EXPECT 20-30 KT WINDS TO CONTINUE ANOTHER 
24-36 HOURS THEN INCREASE TO MINIMAL GALE AGAIN LATE SAT OR EARLY
SUN IN ABOUT 42-48 HOURS AS HIGH PRES BUILDS IN THE SW GULF OF 
MEXICO. 00Z GFS MODEL RUN NOT NEARLY AS BULLISH ON THE PROSPECTS 
FOR ANOTHER ROUND OF GALES...AND AGREES WITH BOTH ECMWF AND UKMET
IN THAT RESPECT. IF TREND CONTINUES WE MAY NEED TO DISCONTINUE 
GALE WARNING AND MAINTAIN 25-30 KT WINDS INSTEAD. DOWNSTREAM 
SEAS WILL SLOWLY SUBSIDE TO 8-10 FT THROUGH THIS EVENING.

FARTHER WEST...PRES GRADIENT BETWEEN A TROUGH JUST W OF THE AREA 
AND HIGH PRES RIDGING OVER THE NW AND N PORTIONS WILL MAINTAIN 
FRESH TO STRONG NE TO E WINDS FROM 09N TO 21N W OF 130W WITH 
SEAS 8 TO 11 FT THE NEXT 24 HOURS. ACTIVE CONVECTION WILL LIKELY 
PERSIST ACROSS THIS AREA THROUGH SAT MORNING DUE TO FAVORABLE 
UPPER LEVEL DIFFLUENCE AND CONTINUED E-NE TRADE WIND CONVERGENCE.

$$
MUNDELL