Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 260920
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC SUN MAY 26 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 
0815 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM 10N86W TO LOW PRES NEAR 
10.5N107W 1010 MB TO 09N120W. ITCZ AXIS CONTINUES FROM 09N120W 
TO 07N130W TO 08N140W. SCATTERED MODERATE CONVECTION IS FROM 10N 
TO 12N BETWEEN 98W AND 100W AND FROM 10N TO 12N W OF 134W.

...DISCUSSION...

ALOFT...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE FORECAST 
AREA W OF 100W. AN UPPER LEVEL TROUGH CROSSES THE NW PART OF THE 
FORECAST REGION AND STRETCHES FROM A RECENTLY FORMED UPPER LOW 
LOCATED NEAR 30N134W TO BEYOND 24N140W. SE OF THE TROUGH...BROAD 
ANTICYCLONIC FLOW IS NOTED. ANOTHER UPPER LEVEL TROUGH IS MOVING 
E OF AREA AND NOW EXTENDS ACROSS NORTH-CENTRAL MEXICO TO NEAR 
16N105W. SOUTHWESTERLY FLOW ALOFT BETWEEN THE WRN MOST TROUGH 
AND AN ANTICYCLONE CENTERED NEAR 16N115W IS ADVECTING DEEP 
TROPICAL MOISTURE FROM THE CENTRAL PACIFIC NEWD TO ACROSS THE 
FAR WRN AND N CENTRAL PORTIONS OF THE DISCUSSION AREA TOWARDS  
SRN CALIFORNIA. E OF 100W...ANOTHER ANTICYCLONE CENTERED OVER 
GUATEMALA COVERS SE MEXICO AND NORTHERN CENTRAL AMERICA. UPPER 
DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS HELPING TO INDUCE 
CLUSTERS OF MODERATE TO STRONG CONVECTION N OF 12N TO THE COAST 
OF EL SALVADOR AND SE GUATEMALA...PARTICULARLY BETWEEN 88W AND 
91W...AND FROM 12N TO 15N BETWEEN 92W AND 95W. 

THERE CONTINUES TO BE LOW CONFIDENCE IN THE DEVELOPMENT OF THREE 
LOW PRES AREAS ALONG THE MONSOON TROUGH. THE GFS GLOBAL MODEL 
CONTINUES TO BE THE MOST AGGRESSIVE INDICATING GENESIS AND 
INTENSIFICATION OF TWO LOW PRES AREAS. ONE IS AN AREA OF 
DISTURBED WEATHER LOCATED A COUPLE OF HUNDRED MILES SOUTH OF EL 
SALVADOR AND GUATEMALA. MOST OF THE CONVECTIVE ACTIVITY 
ASSOCIATED WITH THIS SYSTEM IS LOCATED WELL TO THE N OF THE LOW 
LEVEL CENTER. HOWEVER...SOME GRADUAL DEVELOPMENT OF THIS 
DISTURBANCE IS POSSIBLE OVER THE NEXT FEW DAYS AS IT MOVES 
SLOWLY WEST-NORTHWESTWARD OR WESTWARD. THE OTHER ONE IS LOCATED 
ABOUT 600 MILES SOUTH-SOUTHWEST OF MANZANILLO MEXICO AND 
CONTINUES TO PRODUCE DISORGANIZED SHOWERS AND ISOLATED TSTMS. 
THE 0448 UTC ASCAT PASS SUGGESTS THAT THE LOW LEVEL CENTER IS 
LOCATED FARTHER WEST. ANY DEVELOPMENT OF THIS SYSTEM SHOULD BE 
SLOW TO OCCUR AS IT MOVES LITTLE OVER THE NEXT COUPLE OF DAYS. 
THE THIRD AREA OF DISTURBED WEATHER IS LOCATED BETWEEN THE 
AFOREMENTIONED SYSTEMS...ABOUT 400 MILES SOUTH OF ACAPULCO 
MEXICO. SOME SLOW DEVELOPMENT OF THIS DISTURBANCE IS POSSIBLE AS 
IT MOVES LITTLE OR DRIFTS NORTHWARD OVER THE NEXT FEW DAYS. THIS 
SYSTEM COULD MERGE OR BE ABSORBED BY THE LOW PRES LOCATED S OF 
EL SALVADOR AND GUATEMALA. SEE LATEST TROPICAL WEATHER OUTLOOKS 
FOR PROBABILITY CONDITIONS RELATING TO THESE LOW PRES AREAS.

ELSEWHERE AT THE SURFACE...A 1032 MB HIGH IS ANALYZED NW OF THE 
AREA AT 33N141W WITH A RIDGE EXTENDING SEWD TO NEAR 20N116W. AS 
THIS HIGH PRES MOVES SE TOWARD THE FORECAST REGION...EXPECT 
INCREASING TRADE WINDS ALONG THE SOUTHERN PERIPHERY OF THE RIDGE 
AND N OF THE ITCZ IN ABOUT 24 HOURS WITH BUILDING SEAS TO AROUND 
9 FT. WINDS ARE ALSO FORECAST TO INCREASE TO 20-25 KT JUST WEST 
OF BAJA CALIFORNIA PENINSULA DUE TO A TIGHT PRES GRADIENT 
BETWEEN THE RIDGE AND LOWER PRES OVER MEXICO.

LONG PERIOD CROSS EQUATORIAL SW SWELLS AT 16-18 SECONDS DOMINATE 
MOST OF THE FORECAST WATERS E OF 115W. THESE SWELLS ARE MERGING 
WITH NW SWELLS THAT COVER THE REMAINDER OF THE FORECAST WATERS. 

$$ 
GR