000
AXPZ20 KNHC 040244
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 04 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0245 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG 11N85W TO 09N110W TO 
12N125W TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 
NM N OF AXIS BETWEEN 99W AND 103W. SIMILAR CONVECTION IS NOTED 
WITHIN 60 NM S OF AXIS W OF 132W...AND NEAR 12N125W.

...DISCUSSION...

ALOFT...A DEEP LAYER TROUGH IS APPROACHING THE FAR NW CORNER OF 
THE FORECAST AREA. THIS TROUGH SUPPORTS A COLD FRONT CURRENTLY 
REACHING 30N140W. A WEAKENING TROUGH LIES ALONG 26N137W 17N139W.
A PLUME OF MID/UPPER LEVEL MOISTURE IS BETWEEN THIS TROUGH AND  
AN UPPER ANTICYCLONE LOCATED AT 29N129W. THIS ANTICYCLONE HAS A  
RIDGE TO THE S AND SE TO NEAR 15N121W WITH ANOTHER RIDGE 
EXTENDING N-NE OVER CALIFORNIA AND THE SW CONUS. A CUT-OFF LOW 
IS SPINNING OVER THE NW PORTION OF THE GULF OF MEXICO NEAR 
29N94W. A TROUGH EXTENDS FROM THIS LOW ACROSS CENTRAL MEXICO 
INTO THE EPAC TO A COL NEAR 20N110W. VERY DRY UPPER AIR IS 
INDICATED TO THE W OF THE THIS TROUGH...ROUGHLY COVERING THE 
DISCUSSION AREA N OF 13N BETWEEN 100W AND 122W. AN UPPER 
ANTICYCLONE ASSOCIATED WITH TROPICAL STORM TOMAS LOCATED OVER 
THE CENTRAL CARIBBEAN HAS A RIDGE EXTENDING W ALONG 12N/13N TO 
NEAR 13N110W. UPPER DIFFLUENCE RELATED TO THIS FEATURE IS 
HELPING TO INDUCE SOME CONVECTION ALONG THE ITCZ E OF 103W. 

AT THE SURFACE...AS PREVIOUSLY MENTIONED A COLD FRONT HAS 
REACHED THE FAR NW CORNER OF THE FORECAST AREA. SW WINDS OF 20 
TO 25 KT ARE NOTED AHEAD OF THE FRONT PER AN ASCAT PASS FROM 
1942 UTC AND A SHIP OBSERVATION JUST W OF AREA. A RIDGE COVERS 
THE REMAINDER OF THE N WATERS PARTICULARLY N OF 15N W OF 110W. 
NE TRADES AT 15 TO 20 KT ARE OBSERVED ON THE SOUTHERN PERIPHERY 
OF THE RIDGE FROM 10N TO 18N W OF 125W WITH THE CORRESPONDING NE 
SWELL MIXING WITH NW SWELL. LONG PERIOD NW SWELLS...WAVE PERIODS 
BETWEEN 18 TO 20 SECONDS...CONTINUES TO PROPAGATE SE ACROSS THE 
REGIONAL WATERS REACHING THE SOUTHERN TIP OF BAJA CALIFORNIA THU 
MORNING BECOMING THE PREDOMINATE SWELL ALL WATERS W OF 100W FRI 
MORNING. NLY WINDS OF 20 KT ARE EXPECTED WITHIN 60 NM BEHIND THE 
FRONT WHICH WILL EXTEND FROM 30N133W TO 24N140W THU EVENING.
HIGH PRES IN THE WAKE OF THE FRONT WILL BUILD ACROSS THE REGION 
PRODUCING AN INCREASE IN THE AREA OF THE TRADE WINDS BY FRI 
WHILE THE FRONT IS FORECAST TO GRADUALLY DISSIPATE.

NW WINDS AT 20 IN THE GULF OF CALIFORNIA HAVE DIMINISHED BELOW 
20 KT TONIGHT.

SW WINDS OF 20 KT AND SEAS UP TO 8 FT COVER THE AREA FROM 05N TO 
08N E OF 98W. A FEW SHIP REPORTS AND AN EARLIER ASCAT PASS 
VERIFIED THE PRESENCE OF THESE WIND SPEEDS. LITTLE CHANGE IS 
EXPECTED OVER THE NEXT 48 HOURS.

GAP WINDS...
NORTHERLY WINDS CONTINUE TO SURGE INTO THE GULF OF TEHUANTEPEC. 
IXTEPEC IN MEXICO IS REPORTING SUSTAINED WINDS OF 30 KT WITH 
GUSTS TO 40 KT SINCE EARLY THIS AFTERNOON. BASED ON THE COMPUTER 
MODELS...WINDS ARE EXPECTED TO INCREASE TO GALE FORCE TONIGHT... 
AND TO STORM FORCE THU NIGHT. A STORM WARNING HAS BEEN ISSUED 
ACCORDINGLY. THIS GAP WIND EVENT IS EXPECTED TO PERSIST THROUGH 
AT LEAST SUN MORNING. 

$$
GR