000
AXPZ20 KNHC 111002
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED NOV 11 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0745 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 06N77W 
TO 07N87W TO 06N100W TO 11N123W TO 08N140W. ISOLATED MODERATE 
CONVECTION CAN BE FOUND WITHIN 180 NM N OF THE ITCZ AXIS E OF 
85W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION LIES 
WITHIN 180 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 130W AND 
139W. 

...DISCUSSION...

LONG PERIOD NW SWELL THAT HAS PUSHED THROUGH FORECAST WATERS W 
OF 100W THE LAST FEW DAYS HAS BEGUN TO SUBSIDE WITH  SIGNIFICANT 
WAVE HEIGHTS DOWN TO THE 8 TO 12 FT RANGE. WIND WAVES STEMMING 
FROM THE EASTERLY TRADE WINDS GENERALLY FOUND...ACCORDING TO THE 
0244 UTC QUIKSCAT PASS...FROM 10N TO 20W W OF 115W PERSIST FOR 
THE NEXT FEW DAYS AND HELP KEEP WAVE HEIGHTS ABOVE 8 FT OVER 
MUCH OF THE REGION. A HIGH PRES RIDGE STEMMING FROM A 1038 MB 
HIGH NEAR 41N157W AND EXTENDING SE ACROSS N WATERS FROM 30N135W 
TO NEAR 22N110W  DOMINATES NORTH WATERS AT THE SURFACE. 
HOWEVER...THIS HIGH PRES RIDGE IS CURRENTLY BEING COMPROMISED BY 
A STATIONARY FRONT JUST NORTH OF THE FORECAST AREA. THE 0420 UTC 
QUIKSCAT PASS SHOWS 20 TO 30 KT WINDS ASSOCIATED WITH THE FRONT 
EDGING INTO NW WATERS AT THE MOMENT. THIS FRONT IS FORECAST TO 
DISSIPATE AS IT PASSES E OVER THE NEXT FEW DAYS. 

BROAD UPPER LEVEL DIFFLUENCE BETWEEN A WEAK UPPER TROUGH FROM 
30N110W TO 10N120W AND AN ANTICYCLONE CENTERED NEAR 15N102W IS 
ENHANCING CONVECTION ALONG THE ITCZ OVER WATERS BETWEEN 110W AND 
130W. ISOLATED MODERATE CONVECTION CAN BE FOUND FROM 07N TO 14N 
BETWEEN 111W AND 129W AS A RESULT. THE TROUGH AND ANTICYCLONE 
ARE BOTH EXPECTED TO MIGRATE E OVER THE NEXT TWO DAYS. 
MEANWHILE...THE ITCZ STRONGEST CONVECTION OVER FORECAST 
WATERS...ISOLATED MODERATE FROM 07N TO 14N BETWEEN 111W AND 
129W...LIES UNDER THE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN 
ANTICYCLONE CENTERED NEAR 13N136W.

CLOSER TO SHORE...35 TO 50 KT WESTERLY UPPER FLOW IS INHIBITING 
CONVECTION OVER MEXICO AND ADJACENT WATERS N OF 19N. TO THE 
S...BROAD UPPER LEVEL DIFFLUENCE BETWEEN AN ANTICYCLONE OVER THE 
NW CARIBBEAN AND AN UPPER LOW NEAR THE GALAPAGOS IS ENHANCING 
CONVECTION OVER PANAMA AND COSTA RICA ON THE EASTERN SIDE OF THE 
ITCZ.

GAP WINDS...
THE 0104 UTC QUIKSCAT PASS SHOWED GALE FORCE WINDS TO 40 KT 
FUNNELING THROUGH THE ISTHMUS OF TEHUANTEPEC INTO THE PACIFIC 
FROM THE WESTERN GULF OF MEXICO. N TO NE WINDS IN THE GULF OF 
TEHUANTEPEC WILL INCREASE TO JUST BELOW STORM FORCE THIS MORNING 
AND PERSIST THROUGH TOMORROW MORNING BEFORE BEGINNING TO 
DIMINISH. THE FORECAST CALLS FOR WINDS TO DROP BELOW GALE FORCE 
HERE BY FRI MORNING.

$$
SCHAUER