000
AXPZ20 KNHC 041610
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN NOV 04 2007

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 
1500 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N83W 7N96W 11N111W 9N119W 9N119W. 
SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS BETWEEN 112W 
AND 119W AND BETWEEN 128W AND 134W.

...DISCUSSION...

E OF 120W...
MAIN ISSUE CONTINUES TO BE GALE EVENT IN GULF OF TEHUANTEPEC. 
THIS IS PREDICATED ON STRENGTH AND MOVEMENT OF SURFACE HIGH PRES 
1025 MB BUILDING OVER THE GULF OF MEXICO...AND LOW PRES OVER THE 
WESTERN CARIBBEAN NEAR THE NICARAGUAN COAST. LOW IS MOVING 
ONSHORE AND IS EXPECTED TO WEAKEN FURTHER OVER THE NEXT 24 
HOURS. AT THE SAME TIME...THE HIGH WILL SHIFT S OVER THE 
SOUTHERN GULF OF MEXICO...WEAKENING THE GRADIENT IN PLACE 
THROUGH THE TEHUANTEPEC GAP. WINDS WILL DIMINISH BELOW GALE 
FORCE BY TUE MORNING...ALTHOUGH NOT FOR LONG. CHANGE UP WILL 
COME WITH ARRIVAL OF NEXT REINFORCING FRONT IN THE NORTHERN GULF 
OF MEXICO...FOLLOWED BY ANOTHER HIGH PRES AREA OVER THE NW GULF 
BY WED. THUS STRONG GAP WINDS...POSSIBLY TO GALE FORCE...CAN BE 
EXPECTED THROUGH TEHUANTEPEC BY MIDWEEK. 

MEANWHILE WW3 MODEL CONTINUES TO SHOW SW SWELL OF UP TO 8 FT 
WITH 17 SECOND PERIODS REACHING THE MEXICAN AND CENTRAL AMERICAN 
COASTS BY LATE MON. IN ADDITION TO THE POTENTIAL FOR ROUGH 
SURF...THE LARGE LONG PERIOD SWELL WILL INTERACT WITH THE 
OPPOSING WIND WAVES AND SWELL EMERGING OUT OF THE GULF OF 
TEHUANTEPEC TO CREATE AN AREA OF CONFUSED 8 TO 10 FT SEAS SW OF 
THE GULF OF TEHUANTEPEC IN MIXED SW AND NE SWELL.

OTHERWISE E OF 120W...DEEP LAYER MOISTURE IS MINIMAL AND 
CONVECTION VIRTUALLY NON-EXISTENT. NO BIG WEATHER MAKING 
FEATURES ALOFT OR AT THE SURFACE WORTH MENTIONING.

W OF 120W...
DIVERGENCE ALOFT BETWEEN UPPER RIDGE ALONG 17N AND A LOW 
LATITUDE UPPER CYCLONE OVER 5N117W IS PROMPTING MODEST 
CONVECTION ALONG THE ITCZ BETWEEN 112W AND 119W...WHICH IN TURN 
IS ANALYZED AS A SURFACE TROUGH ON THE LATEST ANALYSIS FROM 
8N114W TO 15N110W. FURTHER W...CONVECTION WITH FORMER TROUGH 
ALONG 135W THE LAST SEVERAL DAYS HAS FALLEN VICTIM TO UPPER 
WESTERLY FLOW AND IS SUBSIDING. MEANWHILE...A PATCH OF MODERATE 
TO FRESH TRADES IS EVIDENT ON SCATTEROMETER IMAGERY S OF HIGH 
PRES TO THE N. BROAD AREA OF SW SWELL IS MARCHING THROUGH THE 
AREA.
$$

CHRISTENSEN