000
AXPZ20 KNHC 240241
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT APR 24 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0130 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG 05N81W TO 
07N110W TO 05N120W TO 06N130W TO 05N140W. NUMEROUS STRONG 
CONVECTION WAS NOTED WITHIN 180 NM W QUADRANT OF A 1006 MB LOW 
PRES NEAR 05N81W ON THE E EDGE OF THE ITCZ. SCATTERED MODERATE 
WITH ISOLATED STRONG CONVECTION WAS FOUND ELSEWHERE FROM 03N TO 
06N BETWEEN 80W AND 87W. SCATTERED MODERATE CONVECTION WAS ALSO 
NOTED WITHIN 150 NM N OF THE ITCZ AXIS BETWEEN 95W AND 98W.

...DISCUSSION...
A MID TO UPPER LEVEL LOW CENTERED E OF THE CENTRAL ROCKIES DRAGS 
A TROUGH SOUTHWESTWARD INTO NEW MEXICO AND NW MEXICO INCLUDING 
THE GULF OF CALIFORNIA. THE SURFACE COLD FRONT HAS MOVED THROUGH 
THE SOUTHERN PLAINS AND THE PRES GRADIENT BETWEEN THIS TROUGH 
AND 1030 MB HIGH PRES N OF THE AREA NEAR 37N140W HAS SLACKENED 
CONSIDERABLY OVER THE PAST 24 HOURS. STRONGEST WINDS ASSOCIATED 
WITH THIS PATTERN NOW LIE NEAR THE SOUTHERN TIP OF BAJA 
CALIFORNIA JUST N OF THE RIDGE AXIS THAT EXTENDS FROM THE HIGH 
CENTER TO NEAR 18N110W...ALTHOUGH THERE HAS BEEN LITTLE NEW DATA 
SINCE THE 1640 UTC ASCAT PASS TO CONFIRM THESE CONDITIONS. AS 
THE COLD FRONT MOVES S THROUGH EASTERN MEXICO OVER THE 
WEEKEND...LOOK FOR THE STRONGEST PRES GRADIENT TO SHIFT S AS 
WELL...CAUSING THE 20 KT WINDS TO MOVE TO THE COASTAL AREA 
NEAR MANZANILLO. SIMILARLY...THE PRES GRADIENT S OF THE HIGH 
BETWEEN IT AND THE ITCZ HAS INDUCED FRESH EASTERLY TRADE WINDS 
OVER W WATERS ACCORDING TO THE 1822 UTC ASCAT PASS. THE HIGH 
PRES SYSTEM IS FORECAST TO CONTINUE TO WEAKEN AS IT IS NUDGED 
SOUTHEASTWARD OVER THE NEXT TWO DAYS BY A COLD FRONT PASSING 
OVER ITS NW EDGE...AND TRADE WINDS WILL SHRINK IN AREA IN 
RESPONSE TO THE WEAKENING HIGH PRES TO THE N.

THERE WERE TWO TROUGHS EMBEDDED IN THE ITCZ AT 0000 UTC. THE 
WESTERN TROUGH WAS ALONG 128W WHILE THE EASTERN TROUGH WAS FROM 
10N111N TO 03N112W. CONVECTION THAT WAS PREVIOUSLY NOTED NEAR 
THE EASTERN TROUGH HAS DISSIPATED OVER THE LAST FEW HOURS...BUT 
MID TO HIGH LEVEL MOISTURE CONTINUES TO BE TRANSPORTED 
NORTHEASTWARD INTO CENTRAL MEXICO FROM THE ITCZ IN THE VICINITY 
OF THIS TROUGH BY A 60-90 KT SOUTHWESTERLY UPPER JET...WITH 
SCATTERED CIRRUS NOTED ALONG ITS PATH. THE STRONGEST CONVECTION 
ALONG THE ITCZ WAS FOUND ON ITS E EDGE WHERE A 1006 MB LOW PRES 
SYSTEM WAS NEAR 05N81W. LOW LEVEL CONVERGENCE WAS NOTED AT 1800 
UTC BETWEEN 20 KT N TO NE WINDS IN THE SW CARIBBEAN AND THE 
20-25 KT S TO SW WINDS NOTED BY SHIP A8IT6 NEAR 05N88W AND A8IP4 
NEAR 01N97W AS WELL AS 18 KT BY BUOY 32303. THERE HAVE BEEN FEW 
OBSERVATIONS IN THE PACIFIC SINCE 1800 UTC...SO THESE CONDITIONS 
ARE BELIEVED TO REMAIN IN PLACE. DIFFLUENT UPPER LEVEL WINDS IN 
THIS REGION ARE EXCEPTED TO STAY IN PLACE IN SE WATERS AND ALLOW 
FOR DEEP CONVECTION TO CONTINUE THERE OVER THE NEXT TWO DAYS. 
THE FORECAST GUIDANCE SHOWS LITTLE AGREEMENT ON THE STRENGTH AND 
POSITION OF THIS FEATURE. THE CURRENT FORECAST CARRIES A 
WEAKENING LOW SLOWLY TO THE NORTHEAST THROUGH SAT EVENING AND 
THEN DISSIPATES THE LOW LEAVING A TROUGH ALONG 87W-88W BY SUN 
EVENING. 

$$
SCHAUER