000
AXPZ20 KNHC 171558
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI OCT 17 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N78W 10N88W 9N98W 10N108W 09N120W 
11N130W 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
IS WITHIN 120 NM N OF THE AXIS BETWEEN 90W AND 96W. SCATTERED 
MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 130W 
AND 133W.

...DISCUSSION...
A 1238 UTC QSCAT PASS REVEALED 20-30 KT N WINDS IN THE GULF OF 
TEHUANTEPEC. THIS GAP WIND EVENT IS NOT ASSOCIATED WITH THE 
CLASSICAL COLD AIR ADVECTION BEHIND A COLD FRONT...BUT RATHER  
WITH THE W PERIPHERY OF THE CIRCULATION OF FORMER T.D. 16 
CENTERED OVER WESTERN EL SALVADOR. GFS/NAM GUIDANCE SUGGESTS 
THAT THIS HIGH WIND EVENT WILL CONTINUE FOR AT LEAST A FEW DAYS 
AND WILL LIKELY REACH GALE FORCE AS A FRONTAL BOUNDARY MAKES 
SOUTHWARD PROGRESS IN THE GULF OF MEXICO SAT NIGHT AND SUN. LAST 
ALTIMETER PASS OVER THE TEHUANTEPEC WAS YESTERDAY AROUND 
19Z...MAX SEAS AT THAT TIME WERE NEAR 8 FT. SEAS ARE LIKELY 
SLIGHTLY HIGHER THAN THAT CURRENTLY...AND ARE EXPECTED TO BUILD 
TO 11 FT THIS WEEKEND.

LOW-LEVEL CONVERGENCE...PARTIALLY ASSOCIATED WITH THE 
TEHUANTEPEC WINDS AND THE REMNANTS OF T.D. 16...ARE CAUSING A 
LINEAR ZONE OF SCATTERED MODERATE TO STRONG CONVECTION WITHIN 
THE ITCZ FROM 10N-13N BETWEEN 87W-97W. 

FARTHER W...ONLY WEATHER MAKER TO SPEAK OF IS THE REMNANTS OF 
MARIE CENTERED NEAR 11N131W. IR IMAGES SHOW SCATTERED TSTMS 
WITHIN 180 NM N SEMICIRCLE. THIS FEATURE IS ONLY EXPECTED TO 
CONTINUE W AS A SLIGHT PERTURBATION IN THE ITCZ. EARLIER ASCAT 
PASS DID INDICATE 20 TO POSSIBLY 25 KT NE WINDS N OF THE 
CENTER...DUE TO THE TIGHTENED PRES GRADIENT BETWEEN IT AND 
TYPICAL SUBTROPICAL HIGH PRES TO ITS N. 

THE REMAINDER OF THE AREA IS RELATIVELY TRANQUIL WITH LITTLE 
DEEP MOISTURE...SUPPRESSED BY A SUBSIDENT ENVIRONMENT ESPECIALLY 
IN THE UPPER CONFLUENT ZONE BETWEEN AN UPPER LOW NEAR 31N128W 
AND AN UPPER RIDGE OVER CENTRAL MEXICO.

$$
CANGIALOSI