000
AXPZ20 KNHC 132218
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI APR 13 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 2145 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N85W 6N100W 6N110W 6N120W 6N130W 
5N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 
120 NM N OF THE AXIS WEST O9F 138W.

...DISCUSSION...
PERSISTENT LONGWAVE TROUGH DOMINATES THE MAJORITY OF THE WESTERN 
AND CENTRAL PORTIONS OF THE REGION. LARGE EMBEDDED CYCLONIC 
CYCLONIC CIRCULATION IS EVIDENT NEAR 32N128W WITH THE MEAN TROUGH
AXIS RUNNING SOUTH THROUGH 25N130W SW TO 21N134W TO 17N140W.
STRONG SUBSIDENCE AND ASSOCIATED DRY SINKING AIR COVERS THE AREA 
FROM 15N-23N WEST OF 132W. MODERATE SUBSIDENCE COVERS THE AREA
ELSEWHERE NORTH OF 15N WEST OF 125W. SURFACE COLD FRONT 
ASSOCIATED WITH THE TROUGH EXTENDS FROM 30N125W TO 20N127W THEN 
DISSIPATING TO 14N140W. THE COLD FRONT WILL FURTHER WEAKEN AS 
ITS REACHES A POSITION FROM SOUTHERN CALIFORNIA TO 24N118W IN 
ABOUT 24 HOURS AND DISSIPATES THEREAFTER THROUGH THE NEXT 48 
HOURS. LARGE NORTH AND NORTHWEST SWELLS WILL CONTINUE TO 
OVERSPREAD THE AREA BEHIND THE FRONT THROUGH THE NEXT 48 HOURS.

AN UPPER LEVEL ANTICYCLONE IS LOCATED NEAR 14N111W WITH A RIDGE 
EXTENDING SW TO BEYOND THE REGION AT 4N140W. A RIDGE ALSO EXTENDS
NE TO ACROSS AND NORTHERN MEXICO AND CONTINUES NE TO THE WESTERN 
GULF OF MEXICO. UPPER DIFFLUENCE UNDER THE RIDGE IS ENHANCING 
CONVECTION ALONG...AND JUST TO THE N OF THE ITCZ...MAINLY W OF 
133W. UPPER DEBRIS MOISTURE FROM THIS CONVECTION SPREADS N ALONG 
THE W PERIPHERY OF THE RIDGE...ROUGHLY WITHIN 240 NM EITHER SIDE 
OF LINE FROM 10N130W TO 20N120W THEN NARROWS AND CONTINUES NE 
ACROSS BAJA CALIFORNIA AND NORTHEASTWARD ACROSS NORTHWEST MEXICO 
AND THE SOUTHWEST UNITED STATES. THIS LINE ALSO DEFINES A STRONG
SUBTROPICAL JET STREAM WITH MAXIMUM WINDS OF UP TO 110 KT NEAR
THE JET CORE.

A SHARP POSITIVE TILT UPPER TROUGH NOTED OVER THE SOUTHWEST NORTH
ATLANTIC EXTENDS SW INTO THE WESTERN CARIBBEAN...THEN CONTINUES 
SW ACROSS GUATEMALA AND HONDURAS AND INTO THE EASTERN PACIFIC TO
NEAR 11N93W.

WEAK MID-UPPER LEVEL RIDGING EXTENDS ALONG 7N E OF 93W. THE 
RIDGE IS ALLOWING FOR SPORADIC ISOLATED CONVECTION TO DEVELOP
ALONG THE ITCZ BETWEEN 82W-88W AND 88W-92W. DEBRIS UPPER LEVEL 
BLOWOFF CLOUDINESS CONTINUES TO BE ADVECTED NORTHEASTWARD INTO 
THE SOUTHWESTERN CARIBBEAN SEA MAINLY ACROSS CENTRAL AMERICA 
SOUTHEAST OF SOUTHERN NICARAGUA.

GAP WINDS...GULF OF TEHUANTEPEC...SHORT TERM GALE EVENT SHOULD
BE VERY CLOSE TO ENDING. NE WINDS OF 20 KT ACROSS THE GULF OF 
PAPAGAYO SHOULD DECREASE TO LESS THAN 20 KT IN ABOUT 6 HOURS.

$$
AGUIRRE