000
AXPZ20 KNHC 010332
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED OCT 01 2008

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0315 UTC.

...SPECIAL FEATURES...
AN AREA OF LOW PRESSURE IS CENTERED ABOUT 300 NM SSW OF THE GULF 
OF TEHUANTEPEC NEAR 12N97W...ANALYZED 1008 MB DRIFTING W. 
EARLIER VISIBLE IMAGERY AND MICROWAVE DATA SUGGESTED THAT THE 
LOW-LEVEL CENTER WAS A LITTLE BETTER ESTABLISHED...BUT IT 
REMAINED EMBEDDED WITHIN AN ELONGATED NE-SW TROUGH. CONVECTION 
IS CONFINED WITHIN 180 NM SW QUADRANT. AN ASCAT PASS FROM 
EARLIER TODAY REVEALED STRONG NE WINDS FUNNELING THRU THE GULF 
OF TEHUANTEPEC AND MODERATE S TO SW CROSS-EQUATORIAL FLOW S OF 
THE SYSTEM. THE COMBINATION OF THESE WIND REGIMES ARE ENHANCING 
THE VORTICITY IN THIS REGION. THIS SYSTEM COULD BECOME A 
TROPICAL DEPRESSION OVER THE NEXT COUPLE OF DAYS AS UPPER WINDS 
ARE SOMEWHAT FAVORABLE.

ANOTHER LOW PRESSURE SYSTEM IS LOCATED ABOUT 500-550 NM SSW OF 
THE SRN TIP OF BAJA CALIFORNIA. THIS LOW IS LARGER THAN THE ONE 
TO THE E AND IT APPEARS TO BE IMPROVING IN STRUCTURE AS IR 
IMAGERY SHOWS INCREASED CURVATURE AND DEEPENING CONVECTION 
IN A LARGE CURVED BAND W OF THE ESTIMATED CENTER. SCATTERED 
MODERATE TO STRONG CONVECTION IS WITHIN 240 NM W AND NW OF THE 
CENTER. AFTERNOON AND EVENING SCATTEROMETER DATA MISSED THIS 
SYSTEM BUT BASED ON AVAILABLE DATA STRONG WINDS ARE OCCURRING SE 
OF THE CENTER OF CIRCULATION. THIS SYSTEM COULD BE A TROPICAL 
CYCLONE BEFORE IT TRACKS OVER COOLER WATERS IN A COUPLE OF DAYS.
  
...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 92W N OF 05N MOVING W 10 KT. THIS WAVE IS 
MOVING INTO THE BROAD TROUGH ASSOCIATED WITH THE SPECIAL FEATURE 
NEAR 12N97W. IT IS LIKELY AIDING IN THE ENHANCEMENT OF SCATTERED 
SHOWERS AND TSTMS WITHIN 240 NM OF THE AXIS N OF 10N.
    
...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N85W 12N100W 13N110W 10N120W  
11N135W 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM 
N AND 240 NM S OF THE AXIS BETWEEN 97W AND 108W...FROM 09N TO 
11N BETWEEN 114W AND 116W...AND WITHIN 90 NM OF THE AXIS W OF 
130W.

...DISCUSSION...

W OF 120W...
AN UPPER TROUGH ALONG 138W IS SUPPORTING A COLD FRONT FROM 
30N134W TO 23N140W. EARLIER SCATTEROMETER DATA SHOWED 20-25 KT S 
TO SW WINDS WITHIN 240 NM E OF THE FRONT. HOWEVER...WINDS HAVE 
LIKELY DIMINISHED SINCE THAT POINT AS THE UPPER SUPPORT IS 
STARTING TO PIVOT NE...ALLOWING THE SFC FRONT TO WEAKEN. THIS 
PROCESS IS EXPECTED TO CONTINUE OVER THE NEXT 24 HOURS AND THE 
BOUNDARY AND ITS WINDS WILL ACCORDINGLY DISSIPATE. LARGE NW 
SWELLS...GENERATED BY THE GALE LOW N OF THE ZONE...WILL SPREAD 
SE OVER THE NEXT COUPLE OF DAYS. 

IN THE TROPICS...A 1010 MB LOW IS LOCATED NEAR 12N137W ENHANCING 
CONVECTION WITHIN THE ITCZ (DESCRIBED ABOVE). THIS WEAK FEATURE 
IS EXPECTED TO DRIFT W AND REMAIN EMBEDDED WITHIN THE ITCZ OVER 
THE NEXT COUPLE OF DAYS.

E OF 120W...
ABUNDANT MOISTURE LIES OVER THE TROPICAL PORTION ON THE S SIDE 
OF A MID-UPPER RIDGE SITUATED JUST S OF BAJA CALIFORNIA. DEEP 
CONVECTION IS MAINLY TIED TO THE SPECIAL FEATURES AND THE ITCZ 
AS DISCUSSED ABOVE. A LARGE AREA OF 8 FT SEAS OR GREATER IS 
ANALYZED ACROSS THE DEEP TROPICS...AND LITTLE CHANGE IS EXPECTED 
OVER THE NEXT COUPLE OF DAYS AS THE LOWS TRACK SLOWLY WESTWARD. 

WINDS CONTINUE TO FUNNEL THROUGH THE GULF OF TEHUANTEPEC TONIGHT 
DUE TO THE TIGHT PRES GRADIENT BETWEEN A TROUGH OF LOW PRES OVER 
THE SE GULF/FLORIDA AND HIGH PRES OVER MEXICO. THESE WINDS MAY 
DIMINISH SOME...BUT THIS GAP WIND EVENT IS EXPECTED TO PERSIST 
FOR A FEW DAYS.

$$
CANGIALOSI