000
AXPZ20 KNHC 131520
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1805 UTC TUE JAN 13 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...
ITCZ IS ALONG 6N77W 5N95W 8N120W 5N140W. SCATTERED MODERATE 
ISOLATED STRONG FROM 08N TO 12N BETWEEN 100W AND 118W.

...DISCUSSION...
AN UPPER LEVEL RIDGE OVER THE W PORTION OF THE DISCUSSION AREA 
WITH AXIS ALONG 135W. A 90 KT JET STREAM IS JUST W OF THE AREA 
WITH CIRRUS CLOUDS WITH TRANSVERSE BANDING...INDICATING POSSIBLE 
HIGH LEVEL TURBULENCE MOVING TROUGH THE RIDGE. UPPER LEVEL 
CYCLONIC CIRCULATION IS CENTERED NEAR 25N128W WITH TROUGH FROM 
THE CIRCULATION TO 12N120W 5N110W. AN ANTICYCLONIC CIRCULATION 
IS NE OF THE CYCLONIC CIRCULATION NEAR 32N122W. MODERATE TO 
STRONG SUBSIDENCE WITH DRY STABLE AIR COVERS THE AREA N OF 24N E 
OF 135W.

MID TO UPPER LEVEL TROUGH WITH AXIS FROM SE TEXAS ACROSS 
NORTHERN MEXICO TO SOUTHERN BAJA CALIFORNIA TO 25N115W. A 90-100 
KT JET STREAM IS S OF OF THE TROUGH AXIS OVER NORTHERN MEXICO. 
SW WINDS SE OF THE TROUGH ARE ADVECTING HIGH LEVEL MOISTURE FROM 
THE ITCZ ACROSS SOUTHERN MEXICO.

STRONG 1036 MB HIGH PRES OVER NORTHERN MEXICO PRODUCING A TIGHT 
PRES GRADIENT...WITH GALE FORCE WINDS BLOWING THROUGH THE GULF 
OF TEHAUNTEPEC. BROAD SURFACE RIDGE IS N OF 15N W OF 120W.

$$
DGS