000
AXPZ20 KNHC 172137
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE NOV 17 2009

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...
AXIS IS ALONG 7N78W 7N100W 6N110W 10N125W 7N140W. SCATTERED 
MODERATE CONVECTION WITHIN 90 NM N OF AXIS BETWEEN 95W AND 100W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM EITHER 
SIDE OF AXIS W OF 134W.

...DISCUSSION...
MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM 32N135W TO 26N140W. A 
BROAD UPPER LEVEL RIDGE IS E OF THE TROUGH WITH ANTICYCLONIC 
CIRCULATION COVERING A LARGE PORTION OF THE DISCUSSION AREA N OF 
15N BETWEEN 105W AND 130W. AN 80-95 KT JETSTREAM ALONG THE N 
SIDE OF THE RIDGE EXTENDS FROM 24N135W TO 26N120W THEN ACROSS 
SOUTHERN BAJA CALIFORNIA INTO CENTRAL MEXICO. THE JET IS 
ADVECTING HIGH LEVEL MOISTURE FROM CONVECTION W OF THE AREA TO 
125W. AN UPPER LEVEL CYCLONIC CIRCULATION CENTERED IN THE DEEP 
TROPICS NEAR 9N115W. UPPER LEVEL DIFFLUENT FLOW IS ENHANCING 
CONVECTIVE ACTIVITY ALONG THE ITCZ W OF 134W. AN UPPER LEVEL
RIDGE EXTENDS FROM SOUTHERN MEXICO NEAR 18N96W TO AN UPPER
LEVEL ANTICYCLONIC CIRCULATION NEAR 8N97W.

STRONG HIGH PRES MOVING THROUGH THE WESTERN GULF OF MEXICO
IS PRODUCING GALE FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC.
THE GALE CONDITIONS ARE EXPECTED TO PERSIST THROUGH TONIGHT THEN 
GRADUALLY DIMINISH WED AFTERNOON AS HIGH PRES SHIFTS E ACROSS 
THE GULF OF MEXICO. A COLD FRONT IS MOVING INTO THE FAR NW 
PORTION OF THE DISCUSSION AREA FROM 32N135W TO 28N140W. OVERCAST 
LOW TOP CLOUDS ARE W OF THE FRONT AND WITHIN 120 NM E OF THE 
FRONT. A 1022 MB SURFACE HIGH PRES IS CENTERED NEAR 29N131W. THE 
HIGH IS PRODUCING STRONG ENOUGH GRADIENT FOR WINDS TO REACH 20 
TO 25 KT FROM 8N TO 22N W OF 120W. BROKEN TO OVERCAST 
STRATOCUMULUS CLOUDS COVER THE AREA N OF 20N BETWEEN 118W-130W.

A COUPLE OF SURFACE TROUGHS ARE ANALYZED ALONG THE ITCZ. ONE
FROM 9N101W TO 4N101W. SCATTERED MODERATE CONVECTION IS WITHIN
60 NM EITHER SIDE OF THE TROUGH N OF 6N. ANOTHER TROUGH EXTENDS 
FROM 12N127W TO 6N127W. ISOLATED SHOWERS ARE ALONG THE TROUGH 
AXIS.

$$
DGS