000
AXPZ20 KNHC 310912
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC FRI MAY 31 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 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

MONSOON TROUGH EXTENDS FROM 13N107W TO 10N115W THEN ITCZ TO 
06N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IN 
GULF OF TEHUANTEPEC N OF 15N BETWEEN 93W AND 95W. 

...DISCUSSION... 

E OF 110W...LATEST SHIP OBSERVATIONS AND SCATTEROMETER DATA 
INDICATE THAT THE FRESH NW FLOW ALONG THE COAST OF MEXICO S OF 
20N APPEARS TO BE DIMINISHING. THESE WINDS WERE RELATED TO THE 
REMNANT LOW OF TROPICAL STORM BARBARA THAT HAS BECOMING AN OPEN 
TROUGH OVER THE FAR SW GULF OF MEXICO. RESIDUAL CONVECTION IS 
ACTIVE THIS MORNING OVER THE GULF OF TEHUANTEPEC...BUT WILL 
LIKELY DIMINISH THROUGH MID MORNING.

FARTHER SOUTH...RECENT SHIP OBSERVATIONS AND A JASON ALTIMETER 
PASS INDICATED A SURGE OF SW FLOW TO 20 KT S OF COSTA RICA AND 
WESTERN PANAMA INTO THE MONSOON TROUGH...NOW LOCATED OVER THE SW 
CARIBBEAN AND CENTRAL AMERICA. A BROAD AREA OF TROUGHING 
EXTENDING THE LENGTH OF MEXICO INTO PACIFIC WATERS S OF 
TEHUANTEPEC INTERRUPTS THE CONTINUITY OF THE MONSOON TROUGH OVER 
THE FAR EASTERN PACIFIC.

1010 MB LOW PRES IS CENTERED NEAR 15N109W...ALMOST DIRECTLY 
UNDER THE CENTER OF A MID LEVEL RIDGE DOMINATING THE PATTERN W 
OF 120W. EARLIER IN THE EVENING THE SE FLOW ON THE SW EDGE OF 
THE RIDGE HAD SHEARED THE CONVECTION TO THE NW OF THE SURFACE 
LOW...AND HAS SINCE COMPLETELY DISSIPATED IN RELATIVELY DRY AIR.

GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING A WEAK PRES PATTERN 
SETTING UP THIS WEEKEND THROUGH EARLY NEXT WEEK WITH 

W OF 110W...STRONG TO NEAR GALE FORCE NW WINDS PERSIST OFF THE 
COAST OF SOUTHERN CALIFORNIA BETWEEN 1028 MB HIGH PRES NEAR 
25N135W AND RESIDENT LOW PRES OVER THE SW UNITED STATES. AN 
ASCAT PASS FROM 0405 UTC INDICATED WINDS TO 20 TO 25 KT N OF 28N 
BETWEEN 120W AND 125W...CONFIRMING AN EARLIER JASON ALTIMETER 
PASS IN THE SAME AREA INDICATING SIMILAR WINDS WITH SEAS TO 10 
FT. 

GLOBAL MODELS ARE IN DECENT AGREEMENT SHOWING WEAK A LOW 
AMPLITUDE SHORT WAVE TROUGH IN THE MID LEVELS OF THE ATMOSPHERE 
DEVELOPING SOUTHERN CALIFORNIA TODAY...AND COMING INTO PHASE 
WITH A MORE SUBSTANTIAL TROUGH DIGGING INTO THE PACIFIC NW 
STATES SAT. THE GFS REMAINS THE MOST AGGRESSIVE SHOWING A CUT OFF 
LOW OFF SOUTHERN CALIFORNIA BY LATE SUN. TO VARYING 
EXTENTS...EACH MODEL INDICATES A SURFACE TROUGH OFF SOUTHERN 
CALIFORNIA AND NORTHERN BAJA BY EARLY NEXT WEEK. MEANWHILE 
RIDGING BUILDS ALONG 140W...STRENGTHENING THE SURFACE HIGH PRES 
AND ALLOWING AN ARC OF FRESH N TO NE WINDS MAINLY W OF 125W AND 
N OF 15N TO SET UP BY SUN. SEAS BUILD ACCORDINGLY TO 8 TO 11 FT 
BY LATE SUN...WITH HIGHEST SEAS N OF 28N BETWEEN 125W ANDS 130W.
 
$$ 
CHRISTENSEN