000
AXPZ20 KNHC 281550
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 28 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 1530 UTC.

...THE ITCZ...
AXIS IS CENTERED ALONG 06N78W TO 09N100W TO 11N112W TO 10N120W 
TO 07N140W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM N AND 
120 NM S OF THE AXIS E OF 98W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS FROM 07N TO 14N BETWEEN 104W AND 116W.

...DISCUSSION...

AN UPPER RIDGE/TROUGH/RIDGE PATTERN IS OVER THE DISCUSSION ZONE 
GENERATING ONLY A FEW PATCHES OF MID-HIGH LEVEL CLOUDS ACROSS 
THE SUBTROPICS. IN THE TROPICS...A SFC TROUGH EMBEDDED IN THE 
ITCZ ALONG 109W HAS IMPROVED IN ORGANIZATION AND GAINED 
CONVECTION. MAIN CAUSE FOR THE INCREASED CONVECTION IS DUE THE 
UPPER DIFFLUENT PATTERN E OF AN UPPER TROUGH. THIS FEATURE WILL 
BE MOVING INTO A SLIGHTLY LESS FAVORABLE ENVIRONMENT SO ANY 
DEVELOPMENT WOULD BE SLOW TO OCCUR. A SHARP AND ELONGATED UPPER 
TROUGH N AND W OF THE ZONE WILL BE PUSHING E DRAGGING A COLD 
FRONT ACROSS THE NW CORNER WED. THIS FRONT WILL THEN WEAKEN THU 
AND FRI AS THE TROUGH CUTS OFF.

LONG PERIOD NW SWELL WITH WAVE PERIODS UP TO 20 SECONDS WILL 
LIKELY BRING LARGE WAVES TO THE N AND W FACING GALAPAGOS ISLANDS 
TOMORROW AND THU. 

GAP WINDS...
THE TIGHT PRESSURE GRADIENT BETWEEN A STRONG EARLY SEASON COLD 
FRONT OVER THE SW ATLC/NW CARIBBEAN AND RIDGING EXTENDING SOUTH 
OVER MEXICO FROM A HEALTHY 1036 MB HIGH OVER THE PLAINS HAS 
PRODUCED A STRONG TEHUANTEPEC EVENT. A HI-RES QSCAT PASS FROM 
AROUND 00Z LAST NIGHT REVEALED 50 KT MAX WINDS. SHIP 9HJD9 
REPORTED 60 KT AT 12Z AND 70 KT WINDS AT 13Z IN THE EXIT LEFT 
REGION OF THE GAP (AREA OF EXPECTED HIGHEST WINDS). A QC OF THE 
SHIP SUGGESTED THAT IT WAS LIKELY BIASED 10-15 KT HIGH. A 13Z 
PARTIAL QSCAT REVEALED MAX WINDS OF 45-50 KT JUST SW OF THE SHIP 
REPORT. GIVEN THIS DATA...IT IS CLEARLY APPARENT THAT STORM 
CONDITIONS ARE OCCURRING IN THE TEHUANTEPEC. THIS IS LIKELY THE 
PEAK OF THE EVENT AS THE FRONT SHIFTS AND HIGH PRES WEAKENS N OF 
THE AREA. HOWEVER...GALE FORCE WINDS ARE LIKELY FOR MUCH OF THE 
WEEK. 

GAP OF PAPAGAYO WINDS ARE ALSO BLOWING BUT ARE LOWER THAN 
WARNING CRITERIA. THIS EVENT...LIKE THE TEHUANTEPEC...WILL BE 
PERSISTING FOR MUCH OF THE WEEK.

$$
CANGIALOSI