000
AXPZ20 KNHC 170935
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU NOV 17 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 THE PACIFIC COAST OF COSTA RICA NEAR 
10N86W TO LOW PRES 1009 MB NEAR 09N93W TO 10N110W. ITCZ AXIS EXTENDS 
FROM 10N110W TO 11N116W TO 09N124W TO 09N140W. CLUSTERS OF SCATTERED 
MODERATE CONVECTION ARE WITHIN 45 NM OF AXIS NEAR 95W 117W AND 139W.

...DISCUSSION...

SCATTEROMETER AND ALTIMETER SATELLITE PASSES OVER THE PAST 12 HOURS 
INDICATE MARINE CONDITIONS OVER NEARLY ALL OF THE REGION ARE BELOW 
HIGH SEAS FORECAST MINIMUM CRITERIA OF 20 KT AND 8 FT SEAS. HIGH 
PRES RIDGE OVER NORTHERN HALF HAS WEAKENED AND PRES GRADIENT BETWEEN
THE RIDGE AND ITCZ ALONG 10N HAS DIMINISHED. ASCAT PASS AT 0456 UTC 
SHOWED FRESH NW WINDS IN THE CENTRAL PART OF THE GULF OF CALIFORNIA 
WITH WINDS TO 20 KT NEAR 26N109.5W. EXPECT ENHANCED NW WINDS TO 20 
KT TO CONTINUE THERE A FEW MORE HOURS THIS MORNING. ALSO EXPECT FRESH
15-20 KT NE TRADE WINDS JUST N OF THE ITCZ AXIS W OF 120W...AND 15-20
KT SW MONSOON WINDS IN THE S SEMICIRCLE OF A WEAK LOW EMBEDDED IN THE
MONSOON TROUGH NEAR 09N93W. OTHERWISE LINGERING NW SWELL AROUND 8 FT 
IS FOUND N OF 27N BETWEEN 115W AND 130W.

EXCEPT FOR BRIEF HIGH WIND EVENT IN THE GULF OF TEHUANTEPEC...EXPECT 
VERY LITTLE SIGNIFICANT CHANGES TO THE OVERALL SYNOPTIC PATTERN THE 
NEXT 24-48 HOURS. A WEAK LOW IN THE MONSOON TROUGH WILL PERSIST NEAR 
95W WHILE SW FLOW PERSISTS S OF 10N AND E OF 100W. NE WINDS FROM THE 
GULF OF TEHUANTEPEC WINDS MAY HELP SPIN UP THE CYCLONIC CIRCULATION 
SOMEWHAT...BUT MID-LEVEL CONDITIONS WILL REMAIN STABLE UNDER LARGE 
SCALE SUBSIDENCE. BEYOND 48 HOURS A NEW SURGE OF NW SWELL WILL REACH 
THE NORTHERN PORTION...WITH SEAS BUILDING TO 10-13 FT BY SAT NIGHT.

NORTHERLY WINDS WILL FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF 
OF TEHUANTEPEC TODAY...AND CONTINUE THROUGH SAT. GFS MODEL GUIDANCE 
CONTINUES TO INDICATE A HIGH LIKELIHOOD FOR GALE FORCE WINDS IN THE 
GULF OF TEHUANTEPEC TONIGHT AND FRI...WITH PEAK WINDS EXPECTED TO BE 
AROUND 40 KT FRI MORNING. THIS HIGH WIND EVENT WILL GENERATE SEAS TO 
13-14 FT...WHICH WILL SPREAD SW AS NE SWELL AND SUBSIDE AS IT MOVES 
AWAY FROM ITS SOURCE THROUGH THE WEEKEND. 

$$
MUNDELL