000
AXPZ20 KNHC 081607
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI APR 08 2011

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 1545 UTC.

...ITCZ...

AXIS ALONG 7N82W 3N94W 3N110W TO BELOW THE EQUATOR AT 127W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S 
OF AXIS BETWEEN 81W AND 87W AND ALSO WITHIN 180 NM N OF THE AXIS 
BETWEEN 91W-95W. SCATTERED MODERATE WITHIN 120 NM N OF AXIS 
BETWEEN 101W -104W.

...DISCUSSION...

W OF 110W...

A RATHER VIGOROUS UPPER LEVEL LOW OVER THE WESTERN U.S. EXTENDS
A TROUGH SW TO INTO THE DISCUSSION AREA THROUGH 32N124W...AND SW
TO 21N130W. THE UPPER FLOW S OF THE TROUGH IS SW TO W E OF 130W
TO AS FAR S AS 13N. THE UPPER LEVEL LOW IS FORECAST TO DROP
S TO SW THROUGH TONIGHT...THEN EJECT NORTHEASTWARD THROUGH SAT 
SWINGING THE TROUGH THROUGH THE NE PORTION. THE ASSOCIATED 
SURFACE COLD FRONT CURRENTLY EXTENDS FROM NORTHERN BAJA 
CALIFORNIA SW TO 27N122W AND TO 28N131W. THE FRONT WILL WEAKEN 
AS IT QUICKLY MOVES E OF THE AREA TONIGHT INTO SAT AFTERNOON. 
EARLY MORNING VISIBLE SATELLITE IMAGERY SHOWS A RATHER EXTENSIVE 
STRATOCUMULUS CLOUD FIELD PRESSING SOUTHWARD INTO THE AREA 
BEHIND THE FRONT DENOTING A SURGE OF COLD AIR ADVECTION. WINDS 
BEHIND THE FRONT ARE NW-N 20-25 KT WITH SEAS 10-14 FT IN LARGE 
NW SWELLS. ONCE THE FRONT MOVES INLAND...WINDS WILL THEN 
DIMINISH TO 20 KT TO THE N OF 25N AND BETWEEN 118W-129W WITH 
SEAS REMAINING LARGE UP TO 16 FT IN NW -N SWELL THROUGH SAT. 
ELSEWHERE RATHER FLAT MID/UPPER LEVEL RIDGING DOMINATES THIS 
AREA WITH THE UPPER FLOW BEING GENERALLY W...EXCEPT S OF 10N 
BETWEEN 110W-125W WHERE IT BECOMES NW-NE. COPIOUS AMOUNTS OF 
DEEP TROPICAL CENTRAL PACIFIC MOSITURE CONTINUES TO ADVECT INTO 
THE DISCUSSION AREA TO THE SW OF THE TROUGH REACHING TO AS FAR E 
AS 126W...AND IS SEEN AS BROKEN TO SCATTERED CIRRUS CLOUDS.

A STRONG 1035 MB HIGH LOCATED NW OF THE AREA NEAR 38N144W EXTENDS
A RIDGE SE TO 23N125W TO NEAR 21N110W. A WEAK SURFACE TROUGH 
MOVING W ABOUT 10 KT IS ALONG 9.5N114W 4N118W. LOW LEVEL 
CONVERGENCE AHEAD OF IT IS RESULTING IN SCATTERED MODERATE 
CONVECTION WITHIN 30 NM OF A LINE FROM 9N114W TO 9N119W.

E OF 110W...

AN UPPER TROUGH EXTENDS FROM 21N107W S TO 15N107W...THEN SW TO
NEAR 6N110W. SATELLITE WATER VAPOR IMAGERY SHOWS MODERATE 
SUBSIDENCE WITHIN 300 NM NW OF THE TROUGH N OF 10N...AND FROM 
10N TO 17N BETWEEN 110W-120W. SCATTERED MODERATE CONVECTION IS 
NOTED WITHIN 60 NM OF THE TROUGH FROM 7N-11N. BROAD E TO W UPPER 
LEVEL RIDGING COVERS THE AREA TO THE E OF THE TROUGH. MIDDLE TO 
UPPER LEVEL MOISTURE ASSOCIATED WITH ITCZ CONVECTION IS TO THE S 
OF THE RIDGE...WITH THE MOISTURE JUST E OF THE TROUGH STREAMING 
NORTHEASTWARD TOWARDS SOUTHEASTERN MEXICO. WIDELY SCATTERED 
SHOWERS AND ISOLATED WEAK CONVECTION IS OCCURRING N OF 13N 
BETWEEN 91W-94W. ELSEWHERE RATHER STABLE CONDITIONS ARE N OF 10N 
AND E OF THE TROUGH.

GULF OF PAPAGAYO NE TO E WINDS OF 20 KT ARE EXPECTED TO BEGIN 
SAT. MORNING WITH LITTLE CHANGE INTO SUN.

$$
AGUIRRE