000
AXPZ20 KNHC 312138
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED OCT 31 2007

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...ITCZ...

ITCZ AXIS CENTERED ALONG 9N80W 6N100W 10N124W 10N140W. SCATTERED 
MODERATE CONVECTION FROM 7N-13N W OF 116W.

...DISCUSSION...

E OF 110W...
A STRONG UPPER LEVEL RIDGE IS ALIGNED ACROSS SRN MEXICO ALONG 
18N WHILE THE ASSOCIATED MID-LEVEL RIDGE IS A BIT FARTHER N 
ALONG 26N. UPPER LEVEL WESTERLIES HAVE ENCROACHED SWD OVER MUCH 
OF NRN MEXICO WITH A FAIRLY WEAK SUBTROPICAL JET EXTENDING INTO 
THE NRN GULF OF MEXICO. THE SUBSIDENCE ASSOCIATED WITH THE 
RIDGES IS PRODUCING A LARGE AREA OF DRY AIR MAINLY W OF 90W WITH 
VERY LITTLE CLOUD COVER IN THE AREA. MUCH OF THIS HAS BEEN 
ENHANCED BY STRONG GAP WIND FLOW THROUGH THE GULF OF 
TEHUANTEPEC...AS THE STREAM CAN BE SEEN IN VISIBLE IMAGERY 
EXTENDING ALL THE WAY SW TO NEAR 7N100W. DEEPER MOISTURE IS 
LOCATED E OF 90W WHERE SWLY FLOW IS BRINGING THE ITCZ ACROSS 
PANAMA INTO THE SW CARIBBEAN. SCATTERED SHOWERS/ISOLATED TSTMS 
ARE OCCURRING OVER MUCH OF PANAMA AND COSTA RICA N OF 6N E OF 
88W.

W OF 110W...
A BROAD UPPER LEVEL RIDGE EXTENDS WWD FROM MEXICO ROUGHLY ALONG 
20N...EXCEPT THAT WATER VAPOR IMAGERY SHOWS A MID-LEVEL TROUGH 
EMBEDDED WITHIN THE RIDGE ALONG 116W SW OF BAJA CALIFORNIA. 
FARTHER W...A CUT-OFF LOW JUST NE OF HAWAII IS PRODUCING SWLY 
FLOW ALOFT OVER THE DISCUSSION AREA N OF 17N W OF 125W. THE FLOW 
IS DIVERGENT IN THE AREA S OF 15N AS SOME OF THE WINDS TURN TO 
THE SE...AND THIS IS ENHANCING CONVECTION ALONG THE ITCZ BETWEEN 
125W-132W. A LOW-LEVEL TROUGH IS LOCATED ALONG 139W AND IS 
ZOOMING TO THE W...EXPECTED TO BE W OF THE DISCUSSION AREA 
TONIGHT. THERE IS SOME SHOWER ACTIVITY ASSOCIATED WITH THE 
TROUGH BUT OVERALL IT IS FAIRLY MINOR. 

$$
BERG