000
AXPZ20 KNHC 182122
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED NOV 18 2009

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.

...ITCZ...
AXIS IS ALONG 9N83W 5N95W 8N100W 5N115W 9N128W 7N140W. NO 
SIGNIFICANT CONVECTION.

...DISCUSSION...
A BROAD UPPER LEVEL RIDGE IS MOVING INTO THE NW PORTION OF THE
DISCUSSION AREA N OF 15N W OF 130W. DOWNSTREAM MID/UPPER LEVEL
SHORTWAVE TROUGH IS APPROACHING THE SOUTHERN CALIFORNIA COAST
FROM 32N120W TO 25N120W. THE COLD FRONT PREVIOUSLY ASSOCIATED
WITH THE TROUGH HAS DISSIPATED. A 90-105 KT JETSTREAM IS S OF 
THE TROUGH FROM 23N140W TO 24N120W THEN ACROSS SOUTHERN BAJA 
CALIFORNIA AND INTO CENTRAL MEXICO. MODERATE TO STRONG SUBSIDENCE
WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS N OF THE
JET. BROKEN TO OVERCAST HIGH CLOUDS ARE WITHIN 300 NM S OF THE
JET AXIS FROM 140W-125W. A BROAD FLAT RIDGE IS S OF THE JET
BETWEEN 115W-130W...WITH AN ANTICYCLONIC CIRCULATION CENTERED
NEAR 13N122W. TO THE E AN UPPER LEVEL CYCLONIC CIRCULATION IS IS 
CENTERED NEAR 12N110W WITH A TROUGH FROM THE CIRCULATION S
TO 5N114W.. MODERATE TO STRONG SUBSIDENCE IS WITHIN 25O NM 
EITHER SID OF THE TROUGH.

STRONG HIGH PRES OVER GULF OF MEXICO IS MOVING E AND THE PRES
GRADIENT HAS WEANED SOME ACROSS SOUTHERN MEXICO AND THE GALE
FORCE WINDS HAVE DECREASE TO 25-30 KT IN THE GULF OF TEHAUNTEPEC 
AND WILL CONTINUE TO DECREASE THROUGH THE NEXT 48 HOURS. SURFACE 
HIGH PRES RIDGE IS N OF 15N W OF 115W. THE HIGH IS PRODUCING 
STRONG ENOUGH GRADIENT FOR WINDS TO REACH 20 TO 25 KT FROM 8N TO 
25N W OF 120W. LARGE NW SWELLS ARE N OF 25N W OF 125W. BROKEN TO 
OVERCAST STRATOCUMULUS CLOUDS COVER THE AREA N OF 20N BETWEEN 
118W-135W.

A COUPLE OF SURFACE TROUGHS ARE ANALYZED ALONG THE ITCZ. ONE 
FROM 13N102W TO 4N102W. A FEW SHOWERS ARE WITHIN 90 NM EITHER
SIDE OF THE TROUGH FROM 7N-10N. ANOTHER TROUGH EXTENDS FROM 
12N130W TO 5N131W. ISOLATED SHOWERS ARE WITHIN 200 NM E OF THE 
TROUGH AXIS. FROM 8N-12N.

$$
DGS