000
AXPZ20 KNHC 280317
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN OCT 28 2007

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.

...ITCZ....
AXIS ALONG 7N78W 7N95W 12N115W 10N127W 11N140W. SCATTERED 
MODERATE WITHIN 60-90 NM OF THE AXIS BETWEEN 130W AND 135W. 

...DISCUSSION...
POSITIVELY TILTED MID/UPPER LEVEL TROUGH EXTENDS FROM AN 
EXPANDING MID LEVEL CYCLONIC CIRCULATION NEAR 34N130W SWWD 
THROUGH 30N132W TO ANOTHER CYCLONIC CIRCULATION NEAR 22N140W TO 
A BASE NEAR 16N144W. STRONG SUBSIDENCE WAS NOTED WITHIN 180 NM 
OF THE NORTHERNMOST CYCLONIC CIRCULATION AND ELSEWHERE WITHIN 
THE TROUGH AXIS WITH MODERATE SUBSIDENCE NOTED OVER MOST OF THE 
REMAINDER OF THE AREA N OF 15N/ITCZ.  DOWNSTREAM RIDGE EXTENDS 
FROM THE SRN ROCKY MOUNTAINS ACROSS NW MEXICO TO A WEAK 
ANTICYCLONE NEAR 18N107W. A BROAD AREA OF SOMEWHAT DIFLUENT SWLY 
FLOW AT THE MID AND UPPER LEVELS WAS NOTED BETWEEN THE RIDGE AND 
TROUGH GENERALLY OVER THE AREA N OF 10N BETWEEN 110W AND 130W. 
THIS FLOW WAS ADVECTING MID TO UPPER LEVEL MOISTURE OVER NRN 
BAJA CALIFORNIA AND THE SW CONUS INTO THE INTERMOUNTAIN WEST.  
 
MID TO UPPER LEVEL TROUGH EXTENDS FROM E TEXAS SWD ACROSS THE 
WRN GULF OF MEXICO TO MEXICO TO A BASE JUST TO THE W OF THE 
ISTHMUS OF TEHUANTEPEC NEAR 16N97W. VERY STRONG SUBSIDENCE WAS 
NOTED ACROSS MEXICO INTO PACIFIC SUPPRESSING ITCZ CONVECTION. 
DIFFLUENCE FROM AN UPPER LEVEL ANTICYCLONIC CIRCULATION IN THE 
WESTERN CARIBBEAN IS ENHANCING CONVECTIVE ACTIVITY FROM PANAMA 
NWWD INTO THE GULF OF HONDURAS.

AT THE SURFACE...A WEAK 1012 MB LOW PRES IS LOCATED NEAR 
16N115W. SFC RIDGE COVERED THE AREA N OF 23N W OF 125W BUT WAS 
GRADUALLY LOSING ITS INFLUENCE OVER THE NW PORTION OF THE AREA. 
HOWEVER...MODERATE TO STRONG NE WINDS OF 25-30 KT WERE STILL 
NOTED OVER THE FAR NW CORNER OF THE AREA. WINDS ARE EXPECTED TO 
DROP TO AROUND 20 KT WITHIN 18-24 HOURS. 

GAP WINDS...
BUILDING SFC RIDGE OVER THE WRN GULF OF MEXICO IS RESULTING IN 
THE SECOND GALE EVENT IN THE GULF OF TEHUANTEPEC THUS FAR THIS 
SEASON. THIS WAS CONFIRMED BY A 0010 UTC QUIKSCAT PASS WHICH 
SHOWED 35 KT WINDS WITHIN 60-90 NM OF THE COAST. THE WINDS ARE 
FCST TO PEAK AROUND 40 KT IN 24 HOURS...BUT REMAIN AT GALE FORCE 
THROUGH 48 HOURS.  

$$
COBB