000
AXPZ20 KNHC 252131
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 25 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 
2100 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 10N85W TO 10N94W...THEN AS ITCZ AXIS 
TO 12N124W TO 07N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM
S OF AXIS W OF 127W. 

...DISCUSSION...

SURFACE OBSERVATIONS AND WINDSAT SCATTEROMETER PASS AT 1220 UTC 
INDICATE STRONG GAP WINDS INTO THE GULF OF TEHUANTEPEC OCCURRING 
THIS AFTERNOON...BUT MODEL GUIDANCE SHOWS WINDS BELOW GALE FORCE 
AT 1800 UTC DIMINISHING FURTHER TONIGHT. GALE WARNING PREVIOUSLY 
IN EFFECT FOR THE GULF OF TEHUANTEPEC HAS BEEN DISCONTINUED. BUT 
EXPECT STRONG TO NEAR-GALE N-NE WINDS TO CONTINUE ANOTHER 24 HRS.
SYNOPTIC FORCING WEAKENS SIGNIFICANTLY WED THROUGH FRI...BUT A 
STRONG COLD FRONT ENTERING THE WESTERN GULF OF MEXICO FRI WILL 
INDUCE ANOTHER TEHUANTEPEC GALE-FORCE WIND EVENT THIS WEEKEND.

DEEPENING UPPER LEVEL TROUGH FROM 36N125W TO 25N135W TO 15N138W 
IS ENHANCING SLY UPPER LEVEL WINDS E OF TROUGH BETWEEN 115W AND 
130W. DIVERGENT FLOW ALOFT IS CREATING A FAVORABLE ENVIRONMENT 
FOR ACTIVE ITCZ CONVECTION W OF 127W. EXPECT TRANSITION TO CUT 
OFF LOW ALONG 135W THROUGH THU WHILE RIDGE BUILDS NEAR 16N115W. 
BOUNDARY LAYER WINDS WILL BECOME EASTERLY ACROSS THE BASIN OVER 
THE NEXT FEW DAYS AS THE SYNOPTIC PATTERN SHIFTS TO PROGRESSIVE 
WEST MOTION FOR ALL SURFACE FEATURES AS MONSOON TROUGH WEAKENS.

A SURFACE TROUGH EXTENDING FROM 19N121W TO 11N127W WILL SHIFT W 
THROUGH THU WHILE HIGH PRES N OF THE DISCUSSION AREA REMAINS 
NEARLY STATIONARY. MODEL GUIDANCE INDICATES WINDS AND SEAS WILL 
BE ELEVATED W OF THE TROUGH AXIS DUE TO ENHANCED PRES GRADIENT. 
LATEST SCATTEROMETER DATA SHOWS WINDS BELOW 20 KT IN NW PORTION 
BUT NE SWELL GENERATED N OF 30N IS PROPAGATING INTO THE REGION 
NW OF A LINE FROM 30N125W TO 20N140W...WITH SEAS TO 11 FT. SEAS 
WILL SLOWLY SUBSIDE IN NW PORTION THROUGH THU MORNING.

FRESH NW WINDS ARE EXPECTED IN THE NORTHERN GULF OF CALIFORNIA 
WED NIGHT THROUGH THU NIGHT. WHILE LOCALIZED WINDS COULD EXCEED 
20 KT DUE TO DIURNAL FUNNELING EFFECTS...SEAS WILL BE LESS THAN 
8 FT.

$$
MUNDELL