000
AXPZ20 KNHC 031611
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT NOV 03 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 9N84W 7N98W 10N109W 12N1135W 
11N140W. SCATTERED MODERATE CONVECTION FROM 10N TO 12N BETWEEN 
88W TO 90W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS 
BETWEEN 108W AND 112W AND WITHIN 90N N OF AXIS BETWEEN 127W AND 
135W.

...DISCUSSION...

E OF 120W...
THE MAIN FORECAST ISSUE IS GALE CONDITIONS IN THE GULF OF 
TEHUANTEPEC. HIGH PRES IS BUILDING OVER THE SOUTHERN U.S. AND 
GULF OF MEXICO. IN ADDITION...LOW PRES IS DEVELOPING OVER THE 
WESTERN CARIBBEAN. THE TIGHTENING GRADIENT IS IS THE IMPETUS OF 
FOR GALE FORCE WINDS THROUGH THE TEHUANTEPEC GAP. EARLIER 
QUIKSCAT DATA AND A RECENT SHIP OBSERVATION SHOW THAT AT LEAST 
30 KT WINDS ARE ALREADY IN PLACE AND IT'S PLAUSIBLE THAT MINIMAL 
GALE CONDITIONS HAVE ALREADY STARTED. THE LOW PRES IN THE 
WESTERN CARIBBEAN IS NOT INITIALIZED VERY WELL IN MOST GLOBAL 
MODELS SO FAR. IF THIS DEEPENS FURTHER AND LINGERS OFF THE 
CENTRAL AMERICAN COAST...WINDS COULD INCREASE SLIGHTLY MORE THAN 
EXPECTED THROUGH THE TEHUANTEPEC AREA...ALTHOUGH LIKELY BELOW 
STORM FORCE CONDITIONS. 

LOOKING AHEAD TO NEXT WEEK...THE OTHER FORECAST ISSUE INVOLVES 
THE SEA CONDITIONS BY MONDAY. THE WW3 MODEL IS SHOWING A LARGE 
BAND OF 8 FT 16S PERIODS SW SWELL MOVING TOWARD THE MEXICAN AND 
CENTRAL AMERICAN COASTS BY MON...WITH ONGOING LARGE SHORT PERIOD 
WIND WAVES AND SWELL THROUGH THE TEHUANTEPEC AREA. THE OPPOSING 
SWELL MAY SET THE STAGE FOR AN AREA OF LARGE AND CONFUSED SEAS 
IN THE TEHUANTEPEC AREA AND JUST TO THE SOUTH MON INTO TUE. IN 
ADDITION...THE LARGE SWLY SWELL WILL PRESENT THE POSSIBILITY OF 
LARGE AND HAZARDOUS SURF CONDITIONS ALONG THE MEXICAN AND 
CENTRAL AMERICAN COASTS EARLY NEXT WEEK. 

OTHERWISE...CONVECTION REMAINS LIMITED WITH DEEP LAYER MOISTURE 
LACKING...AND ELY SHEAR ALOFT. 

W OF 120W...
WEAK DIVERGENCE ALOFT ON THE SOUTHERN EDGE OF A LOW AMPLITUDE 
UPPER TROUGH ALONG 135W IS SUPPORTING MODEST CONVECTION ALONG 
THE ITCZ BETWEEN 127W AND 135W. AN ASSOCIATED SURFACE TROUGH IS 
ANALYZED ALONG 136W. THE GRADIENT BETWEEN THIS TROUGH AND HIGH 
PRES N OF THE AREA IS SUPPORTING A BROAD AREA OF MODERATE TO 
FRESH TRADES BETWEEN 12N AND 24N. OTHERWISE...MIXED NW AND NE 
SWELL IS PUSHING INTO THE WATERS N OF 24N W OF 125W. CROSS 
EQUATORIAL SWLY SWELL OF 8 TO 10 FT WITH 16S PERIODS WILL PUSH 
THROUGH THE AREA OVER THE NEXT 48 HOURS. 

$$
CHRISTENSEN