000
AXPZ20 KNHC 042139
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU NOV 04 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2045 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 10N85W TO 
07N100W TO 12N120W TO 09N140W. SCATTERED MODERATE CONVECTION IS
WITHIN 90 NM S OF AXIS BETWEEN 124W AND 130W. SIMILAR CONVECTION 
IS ALSO NOTED NEAR 11N138W.

...DISCUSSION...
ALOFT...A LONGWAVE TROUGH ENTERS THE DISCUSSION AREA NEAR 
30N140W AND EXTENDS MAINLY SOUTH TO NEAR 14N. A 65-75 KT 
JETSTREAM IS E OF THE TROUGH AXIS FROM 29N134W TO BEYOND 
32N136W. UPPER LEVEL DIFFLUENCE SE OF THE TROUGH AXIS IS 
ENHANCING ITCZ CONVECTION W OF 124W. AN ANTICYCLONIC CIRCULATION 
IS NEAR 29N117W WITH A RIDGE EXTENDING TO THE N OVER THE WESTERN 
CONUS. UPPER LEVEL MOISTURE IS STREAMING N BETWEEN THE RIDGE AND 
TROUGH AXIS N OF ITCZ COVERING ROUGHLY THE AREA FROM 125W TO 
133W. OTHERWISE...MODERATE TO STRONG SUBSIDENCE WITH DRY AND 
STABLE AIR AT THE MIDDLE AND UPPER LEVELS CAN BE FOUND N OF THE 
ITCZ E OF 125W. A DEEP LAYER TROUGH STRETCHES FROM THE SE U.S. 
TO CENTRAL MEXICO INTO THE EPAC TO NEAR 20N105W. A RIDGE EXTENDS 
FROM THE SW CARIBBEAN ACROSS CENTRAL AMERICA TO 10N90W THEN NW 
TO 15N110W.

AT THE SURFACE...A COLD FRONT IS OVER THE NW PORTION OF THE AREA 
EXTENDING FROM 30N135W TO 26N140W. THE AFOREMENTIONED LONGWAVE 
TROUGH SUPPORTS IT. NW TO N WINDS OF 20 KT ARE NOTED BEHIND THE 
FRONT WHILE SW WINDS OF 20 KT ARE WITHIN 60 NM SE OF FRONT. A 
WEAKENING RIDGE COVERS THE REMAINDER OF THE REGION N OF 15N W OF 
110W. HIGH PRES IN THE WAKE OF THE FRONT WILL BUILD ACROSS THE 
FORECAST AREA PRODUCING AN INCREASE IN THE AREA OF THE TRADE 
WINDS BY FRI WHILE THE FRONT IS FORECAST TO GRADUALLY DISSIPATE 
OVER THE NEXT 48 HOURS AS IT MOVES SE ACROSS THE N WATERS.

LONG PERIOD NW SWELL...WAVE PERIODS BETWEEN 18 TO 20 SECONDS... 
CONTINUES TO PROPAGATE SE ACROSS THE REGIONAL WATERS AND WILL 
BECOME THE PREDOMINATE SWELL ALL WATERS W OF 100W FRI MORNING. 

FURTHER SOUTH...SHIP AND BUOY OBSERVATIONS SHOW A SWATH OF FRESH 
SW WINDS FROM 05N TO 08N E OF 90W TO INCLUDE THE APPROACHES TO 
THE GULF OF PANAMA...IN RESPONSE TO T.S. TOMAS PUSHING W THROUGH 
THE CENTRAL CARIBBEAN. THIS FLOW WILL DIMINISH IN ABOUT 24 HOURS 
AS TOMAS SHIFTS NE AND AS STRONG N WINDS PUSH INTO THE WESTERN 
CARIBBEAN. FOR THE SAME REASON...EXPECT FRESH FLOW THROUGH THE 
GULF OF PAPAGAYO BY SAT.

GAP WINDS...
NORTHERLY WINDS CONTINUE TO SURGE INTO THE GULF OF TEHUANTEPEC.  
IXTEPEC IN THE STATE OF OAXACA MEXICO IS REPORTING SUSTAINED 
WINDS OF 40 KT WITH GUSTS TO 50 KT SINCE 1700 UTC. IN 
ADDITION...VISIBLE SATELLITE IMAGERY SHOWS A ROPE CLOUDS THAT 
DELINEATES THE LEADING EDGE OF NLY WIND FLOW ACROSS THE ISTHMUS. 
THE GFS SHOWS 30M WINDS REACHING 50 KT TONIGHT AND TOMORROW 
MORNING...AND A STORM WARNING IS IN EFFECT FOR THIS TIME FOR THE 
GULF OF TEHUANTEPEC. WINDS WILL DIMINISH TO GALE FORCE LATER 
FRI...BUT THEN PERSIST INTO THE WEEKEND. ASSOCIATED SEAS WILL 
BUILD IN EXCESS OF 15 FT TONIGHT. THESE SHORTER PERIOD SEAS OUT 
OF THE NE WILL MIX WITH THE LONGER PERIOD NW SWELL TO CREATE AN 
AREA OF CONFUSED SEAS ROUGHLY FROM 05N TO 15N BETWEEN 95W AND 
105W.

$$
GR