000
AXPZ20 KNHC 022121
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI NOV 02 2007

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N77W 6N100W 11N134W 11N140W. 
ISOLATED SHOWERS/TSTMS WITHIN 45 NM OF AXIS BETWEEN 117W-125W. 
SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS BETWEEN 
133W-137W.

...DISCUSSION...

E OF 120W...
A DOMINATING UPPER RIDGE AXIS IS IN CONTROL ALONG 18N WITH 
MODERATE/STRONG SUBSIDENCE COVERING ALMOST THE ENTIRE 
REGION...EXCEPT FOR INCREASED ATMOSPHERIC MOISTURE ACROSS PARTS 
OF CENTRAL AMERICA AND THE ADJACENT WATERS FROM HONDURAS SEWD. 
MID-LATITUDE WESTERLY FLOW LIES N OF THE RIDGE ACROSS MEXICO 
WITH AN EMBEDDED SHORTWAVE TROUGH ALONG 105W AND ANOTHER ALONG 
114W NEAR BAJA CALIFORNIA. VISIBLE IMAGERY SHOWS A STRONG DRY 
SURGE HAS CLEARED OUT THE ATMOSPHERE FROM THE MEXICAN COAST WWD 
WITHIN A BELT BETWEEN 10N AND 23N. N OF 23N...THE SUBTROPICAL 
RIDGE IS ADVECTING A BROKEN STRATOCUMULUS FIELD DOWN THE BAJA 
COAST BUT MOST OF THE LOW STRATUS/FOG HAS DISSIPATED ALONG THE 
IMMEDIATE COAST WITH DAYTIME HEATING.

THE GULF OF TEHUANTEPEC GAP WIND FLOW CONTINUES TO BE SEEN IN 
SATELLITE IMAGERY EXTENDING WELL S TO 9N. IN FACT...WINDS HAVE 
BEEN STRONG ENOUGH FOR SEVERAL DAYS SUCH THAT COASTAL UPWELLING 
HAS COOLED SEA SURFACE TEMPERATURES TO ABOUT 65 F (18 C) WITHIN 
THE GULF WHILE WATERS JUST TO THE E AND W ARE STILL NEAR 85 F 
(30 C). MODEL GUIDANCE CONTINUES TO SHOW HIGH PRES BUILDING OVER 
THE GULF OF MEXICO WHICH WILL INCREASE WINDS OVER TEHUANTEPEC TO 
GALE FORCE ONCE AGAIN LIKELY BEGINNING TONIGHT AROUND 06Z. NAM 
GUIDANCE IS A LITTLE HIGHER THAN THE GFS AT THIS POINT...BUT 
GIVEN THE VERY COOL SSTS THE REGION MAY BE TOO STABLE FOR THE 
STRONGER NAM WINDS STRONG WINDS.

W OF 120W...
THE UPPER RIDGE AXIS EXTENDS FROM 17N120W SW TO 10N140W AND 
SEPARATES DRY TO THE S FROM DEEPER MOISTURE TO THE N. THE FLOW N 
OF THE RIDGE IS SWLY AHEAD OF A SHEARED TROUGH WHICH EXTENDS 
FROM CALIFORNIA SW TO NEAR THE HAWAIIAN ISLANDS...AND MOISTURE 
FROM CONVECTION OVER THE CENTRAL PACIFIC ITCZ IS BEING DRAWN 
NEWD ACROSS THE AREA. IN ADDITION...WIDESPREAD STRATOCUMULUS 
LIES N OF 20N MOVING AROUND THE SUBTROPICAL HIGH. TO THE S...A 
WELL-DEFINED TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 135W 
MOVING W 10-15 KT AND IS PRODUCING SCATTERED TSTMS IN ITS 
VICINITY. IT IS EXPECTED TO MOVE W OF 140W WITHIN THE NEXT 24 
HRS.

$$
BERG