000
AXPZ20 KNHC 300848
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED MAR 30 2011

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0745 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED FROM 08N28W 
TO 07N84W TO 03N90W TO 05N105W TO 02N140W. SCATTERED MODERATE 
CONVECTION WITHIN 180 NM S OF THE ITCZ AXIS BETWEEN 84W AND 
86W...WITHIN 90 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 91W AND 
99W...AND WITHIN 90 NM N OF THE ITCZ AXIS BETWEEN 119W AND 125W. 
ISOLATED MODERATE WITHIN 120 NM N AND 90 NM S OF THE ITCZ AXIS E 
OF 85W.


...DISCUSSION...

A 1034 MB HIGH PRES SYSTEM NEAR 35N133W EXTENDS A RIDGE INTO THE 
FORECAST AREA NEAR 32N131W TO 14N104W. FRESH NE TRADE WINDS LIE 
S OF THE RIDGE AXIS TO 04N W OF 125W ACCORDING TO THE 0254 UTC 
WINDSAT PASS. THESE TRADES ARE FORECAST TO SHRINK SOUTHWESTWARD 
IN AREA OVER THE NEXT TWO DAYS AS THE HIGH PRES SYSTEM WEAKENS 
AND MIGRATES TO THE W. 

THE PRES GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND LOWER PRES 
OVER BAJA CALIFORNIA CONTINUES TO BE STRONG ENOUGH TO SUPPORT 
FRESH NW TO N WINDS N OF 26N BETWEEN 118W AND 125W ACCORDING TO 
THE 0458 UTC ASCAT PASS. THIS AREA OF WIND IS EXPECTED TO SHIFT 
FARTHER W THROUGH THU AS DEEP LAYER TROUGHING CONTINUES TO BUILD 
OVER BAJA CALIFORNIA AND THE SUBTROPICAL HIGH SHIFTS W...PUSHING 
THE TIGHTEST PRES GRADIENT FARTHER W. THE SUBTROPICAL HIGH WILL 
WEAKEN ENOUGH BY THU AFTERNOON FOR THESE WINDS TO DIMINISH BELOW 
ADVISORY CRITERIA.

AN UPPER TROUGH LIES FROM CENTRAL BAJA CALIFORNIA THROUGH 
29N127W TO AN UPPER LOW NEAR 28N140W. A 70-90 KT WESTERLY UPPER 
JET LIES S OF THIS TROUGH AXIS. THE JET TURNS MORE SOUTHWESTERLY 
TO THE W OF THE UPPER LOW...ALLOWING IT TO TAP INTO SUBTROPICAL 
MOISTURE SW OF HAWAII THAT IT IS TRANSPORTING EASTWARD ACROSS 
THE AREA BETWEEN 15N AND 25N. RIDGING WILL GRADUALLY BUILD 
BETWEEN THE UPPER LOW AND THE TROUGHING OVER NORTH AMERICA OVER 
THE NEXT TWO DAYS...BREAKING THE TROUGH IN HALF. THIS WILL CUT 
OFF THE SUBTROPICAL MOISTURE SUPPLY ALOFT INTO EASTERN WATERS.

A WEAK ANTICYCLONE ALOFT LIES NEAR 08N88W AND EXTENDS A RIDGE 
NORTHEASTWARD INTO PANAMA AND SOUTHWESTWARD TO 02N120W. 
CONVECTION ALONG THE ITCZ PRIMARILY LIES E OF 100W AND COINCIDES 
WITH DIFFLUENCE ASSOCIATED WITH THE RIDGE AXIS ALOFT. MAXIMA OF 
PRECIPITABLE WATER LIE JUST N OF THE GALAPAGOS AND NEAR THE GULF 
OF PANAMA IN THE REGIONS OF CONVECTION DESCRIBED IN THE ITCZ 
SECTION ABOVE.

$$
SCHAUER