000
AXPZ20 KNHC 091525
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 09 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.
  
...TROPICAL WAVE...
A TROPICAL WAVE ALONG 135W HAS MOVING W 10 TO 15 KT. THE WAVE IS 
MOVING WWD AND AWAY FROM MAIN CONVECTION ALONG ITCZ.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS 13N88W 10N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 11N TO 13N 
BETWEEN 90W AND 94W...AND FROM 9N TO 13N BETWEEN 124W AND 133W. 
SCATTERED MODERATE FROM 11N TO 15N BETWEEN 105W AND 111W. 

...DISCUSSION...

THE UPPER PATTERN REMAINS FAIRLY AMPLIFIED...WITH A NE-SW 
ELONGATED UPPER RIDGE EXTENDING FROM AN UPPER ANTICYCLONE OVER N 
CENTRAL MEXICO NEAR 27N103W TO NEAR 11N140W. AN UPPER TROUGH 
EXTENDS FROM AN UPPER LOW OVER SRN CALIFORNIA TO ANOTHER WEAK 
UPPER CYCLONE NEAR 25N140W. THE RIDGE AXIS WILL FLATTEN OUT AND 
BECOME MORE E-W ORIENTED AHEAD OF THE UPPER LOW MOVING INTO SRN 
CALIFORNIA AND MORE PROMINENT TROUGH MOVING W THROUGH 135W.

E OF 120W...MAIN WEATHER MAKER IS QUASI-STATIONARY SURFACE LOW 
CENTERED OVER NW CARIBBEAN NEAR BELIZE COAST...PROMPTING 
MODERATE TO FRESH SWLY FLOW OVER PACIFIC WATERS S OF THE ITCZ 
AND INTO THE CENTRAL AMERICAN COAST. LOW PRES REMAINS WEAK...BUT 
IT POSITION MAY INCREASE WINDS SLIGHTLY OVER GULF OF TEHUANTEPEC 
IN THE NEXT COUPLE DAYS. WHILE QUIKSCAT AND LAND BASED 
OBSERVATIONS DO NOT SHOW THIS YET...SOME SHIP OBSERVATIONS HINT 
THE TEHUANTEPEC GAP WINDS MAY BE STARTING. THE CONVERGENCE OF 
THE SWLY FLOW IS PROVIDING SOME SUPPORT TO CONVECTION ALONG THE 
ITCZ...ESPECIALLY IN AREAS WHERE WEAK TROUGHS ARE PRESENT NEAR 
91W AND 107W. FURTHER NORTH...THE PRESSURE GRADIENT WILL TIGHTEN 
BETWEEN THE TROUGH DIGGING INTO THE SW U.S. AND A SURFACE RIDGE 
FURTHER W...INCREASING NLY FLOW SLIGHTLY OFF THE BAJA COAST IN 
THE NEXT 48 HOURS.

W OF 120W...A COLD FRONT ASSOCIATED WITH THE BROAD UPPER TROUGH 
TO THE N WILL CONTINUE TO PUSH SE INTO THE NW DISCUSSION 
AREA...ACCOMPANIED BY INCREASED WINDS AND SWELL. THE FRONT WILL 
STALL THEN DISSIPATE N OF 27N AS HIGH PRES BUILDS INTO THE AREA 
BUT REMNANT SWELL IN EXCESS OF 8 FT WILL PENETRATE AS FAR S AS 
15N THROUGH FRI. MEANWHILE MODEST CONVECTION PERSISTS W OF 124W 
ALONG THE ITCZ AIDED BY UPPER DIVERGENCE AND EXHAUST BETWEEN THE 
UPPER RIDGE AXIS AND THE UPPER TROUGH.

$$
CHRISTENSEN