000
AXPZ20 KNHC 220951
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC MON APR 22 2013

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0730 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 07N77W TO 06N88W. THE 
ITCZ AXIS WAS ANALYZED FROM 06N88W TO 06N91W TO 04N94W TO 
07N107W TO 05N122W TO 06N130W TO 06N140W. SCATTERED MODERATE TO 
STRONG CONVECTION WAS WITHIN 150 NM EITHER SIDE OF THE AXIS 
BETWEEN 120W AND 128W. SCATTERED MODERATE CONVECTION WAS BETWEEN 
60 NM AND 180 NM S OF THE AXIS BETWEEN 84W AND 87W AS WELL AS 
WITHIN 30 NM N AND 120 NM S OF THE AXIS BETWEEN 92W AND 95W. 
ISOLATED MODERATE CONVECTION WAS WITHIN 150 NM S OF THE AXIS 
BETWEEN 100W AND 110W AS WELL AS N OF THE AXIS TO 10N BETWEEN 
110W AND 116W. 

...DISCUSSION...                                                 
A WEAKENING ANTICYCLONE ALOFT CENTERED NEAR 15N95W EXTENDS RIDGE 
AXES NORTHWESTWARD THROUGH 20N110W TO 32N121W...SOUTHEASTWARD 
ALONG THE WEST COAST OF CENTRAL AMERICA AND SOUTHWESTWARD TO 
11N112W WHERE IT IS DISRUPTED BY AN UPPER TROUGH THEN CONTINUES 
FROM 08N119W TO ANOTHER ANTICYCLONE JUST W OF THE AREA NEAR 
01N143W. UPPER DIFFLUENCE ASSOCIATED WITH THE RIDGE AXIS IS MOST 
VIGOROUS TO THE W OF THE TROUGH WHERE SCATTERED MODERATE TO 
STRONG CONVECTION IS NOTED NEAR THE ITCZ AXIS BETWEEN 120W-128W. 
THIS REGION ALSO CORRESPONDS TO THE HIGHEST PRECIPITABLE WATER 
VALUES OBSERVED IN THE FORECAST AREA. THE AFOREMENTIONED TROUGH 
AXIS SNAKES BETWEEN AN UPPER LOW NEAR 01S108W TO ANOTHER UPPER 
LOW NEAR 32N127W. THE TROUGH AXIS AND BOTH LOWS ARE EXPECTED TO 
SHIFT 5-10 DEGREES FARTHER E OVER THE NEXT 48 HOURS WHILE THE 
TRANSVERSING RIDGE AXIS SHIFTS 5-10 DEGREES FURTHER S. THE WEAK 
SURFACE REFLECTION OF THE TROUGH...CURRENTLY FOUND ALONG 117W 
FROM 05N-08N...SHOULD BECOME MORE PRONOUNCED BY THE END OF THE 
FORECAST PERIOD EARLY WED MORNING. THE MAIN IMPACT ON SENSIBLE 
WEATHER WILL CONTINUE TO BE ENHANCED PRECIPITATION ALONG THE 
ITCZ. 

THE 1033 MB SUBTROPICAL HIGH LIES WELL N OF THE AREA NEAR 
42N137W AND EXTENDS A RIDGE AXIS SOUTHEASTWARD THROUGH 28N130W 
TO 20N112W. GENTLE TO MODERATE NE TRADE WINDS LIE BETWEEN THE 
RIDGE AXIS AND THE ITCZ OVER WESTERN WATERS. WINDS ARE EXPECTED 
TO REMAIN BELOW 25 KT OVER THE ENTIRE FORECAST AREA THROUGH AT 
LEAST EARLY WED MORNING...BUT N WINDS ALONG THE CALIFORNIA COAST 
N OF THE AREA SHOULD BECOME STRONG ENOUGH TO PROPAGATE N SWELL 
WITH 8-9 FT SEAS INTO WATERS N OF 28N BETWEEN 128W-135W TUE 
THROUGH EARLY WED MORNING. SOME RESIDUAL NE SWELL FROM THE 
FORMER GALE IN THE GULF OF TEHUANTEPEC CONTINUES TO KEEP SEAS TO 
8 FT SE OF THE GULF AS IT MERGES WITH DAMPENING CROSS-EQUATORIAL 
SW SWELL. COMBINED SEAS WILL GRADUALLY SUBSIDE BELOW 8 FT TODAY.

$$
SCHAUER