000
AXPZ20 KNHC 272204
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN MAR 27 2011

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 245 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 7N81W
4N94W 4N110W 2N123W 3N140W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS WITHIN 60 NM N OF THE AXIS BETWEEN 112W-115W...AND
WITHIN 30 NM EITHER SIDE OF THE AXIS BETWEEN 125W-130W. SCATTERED
MODERATE CONVECTION IS WITHIN 60 NM S OF THE AXIS W OF 138W.

...DISCUSSION...

A FAIRLY PROGRESSIVE UPPER FLOW REMAINS IN PLACE ALOFT ACROSS 
THE DISCUSSION AREA. THE TAIL END OF A DAMPENING UPPER TROUGH 
NOW OVER THE WESTERN U.S. EXTENDS SW INTO THE REGION THROUGH
32N122W AND REACHES TO NEAR 25N129W. BROAD W TO NW FLOW INTO THE
BACKSIDE OF THE TROUGH EXTENDS AS FAR S AS 30N AND E OF 123W.
TO THE S BROAD SWLY FLOW COVERS JUST ABOUT THE ENTIRE AREA TO 9N 
AND TO THE E OF AN UPPER LEVEL TROUGH THAT STRETCHES FROM 
19N131W SE TO 13N128W TO 5N127W. TO THE W OF THIS TROUGH...THE 
UPPER FLOW BECOMES VASTLY ANTICYCLONIC. A JET STREAM BRANCH 
RIDES OVER THE NORTHERN CREST OF THE ANTICYCLONIC FLOW...AND 
ENTERS THE REGION THROUGH 19N140W. IT THEN CONTINUES ENE TO 
20N130W TO 21N119W...AND TO ACROSS SOUTHERN BAJA CALIFORNIA TO 
INLAND CENTRAL MEXICO. UPPER AIR DATA INDICATES MAXIMUM WINDS OF 
60-80 KT ARE OCCURRING WITHIN ABOUT 360 NM S OF THIS JET. THESE 
WINDS ARE ADVECTING UPPER LEVEL MOISTURE IN THE FORM OF MOSTLY 
BROKEN HIGH CIRRUS CLOUDS NE TO ACROSS THE FAR EASTERN PORTION 
OF THE AREA FROM 17N-22N AND TO THE E OF THE UPPER TROUGH.

OVER THE FAR SOUTHERN PORTION OF THE AREA...MID/UPPER LEVEL 
RIDGING
IS PRESENT S OF THE JET STREAM AND BETWEEN 99W-127W. A RATHER 
SHARP MOSTLY MID LEVEL TROUGH IS NOTED FROM NEAR 11N98W TO 
2N96W. IT HAD RECENTLY TRIGGERED OFF SCATTERED SHOWERS AND TSTMS
ALONG THE ITCZ WITHIN 180 NM TO ITS E...BUT HAVE SINCE HAVE 
DISSIPATED
IN MODERATE TO STRONG SUBSIDENCE AS NOTED IN WATER VAPOR 
IMAGERY. TO THE SE OF THIS TROUGH...A SMALL UPPER LEVEL 
ANTICYCLONE
IS CENTERED NEAR 3N86W WITH A RIDGE NNW TO 10N90W. MODERATE 
SUBSIDENCE
ALLOWING FOR GENERALLY STABLE ATMOSPHERIC CONDITIONS COVERS THE 
AREA
E OF ABOUT 107W.

AT THE SURFACE...A WEAKENING COLD FRONT ASSOCIATED WITH THE 
ABOVE MENTIONED UPPER TROUGH IS APPROACHING 32N140W. THE FRONT 
WILL
CONTINUE TO WEAKEN THROUGH THE NEXT 48 HOURS AS HIGH PRES BUILDS 
IN
ITS WAKE. THE EASTERN MOST EXTENSION OF THE HIGH PRES EXTENDS SE
INTO THE AREA THROUGH 32N140W AND TO NEAR 19N113W. HIGH PRES 
COVERS
THE DISCUSSION AREA N OF 14N AND W OF 113W. FRESH NE TRADE WINDS 
ARE PRESENT S OF THE RIDGE AXIS FROM 4N TO 19N W OF 125W. THESE
TRADES ARE EXPECTED TO SHIFT W AFTER THE NEXT 24 HOURS WHILE 
EXPANDING
N TO 24N AS THE HIGH PRES AREA NW OF THE REGION CONTINUES TO 
BUILD
E AND SE BEHIND THE WEAKENING COLD FRONT.

THE PRES GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND LOWER PRES 
OVER NORTHERN MEXICO IS RESULTING IN NW TO N WINDS OF 20-25 KT
N OF 24N E OF 117W TO THE BAJA CALIFORNIA COAST. THESE WINDS ARE 
EXPECTED TO DIMINISH TO WITHIN THE AREA N OF 27N BETWEEN 119W 
AND 127W IN 48 HOURS.

$$
AGUIRRE