000
AXPZ20 KNHC 060919
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC THU JUN 06 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 FROM 16N98W TO 08N118W. ITCZ FROM 08N118W TO 
07N120W TO 08N140W. NO SIGNIFICANT CONVECTION NOTED.

...DISCUSSION...                                                

THE MAIN ISSUE CONTINUES TO BE LONG PERIOD SW SWELL WITH HEIGHTS 
TO 9 FT REACHING THE COAST FROM PANAMA TO SOUTHERN BAJA THIS 
MORNING...AND PERSISTING THROUGH TONIGHT BEFORE SUBSIDING EARLY 
FRI. THE SW SWELL MAY CAUSE HAZARDOUS BREAKING SURF CONDITIONS 
ALONG EXPOSED REEFS AND COASTS. BEACHGOERS...SURFERS...AND 
SWIMMERS ARE URGED TO USE EXTREME CAUTION TODAY. VESSELS SHOULD 
USE CAUTION APPROACHING EXPOSED PIERS AND JETTIES.

N OF 20N...AN UPPER TROUGH EXTENDS FROM N CENTRAL CALIFORNIA TO 
28N138W TO W OF THE AREA NEAR HAWAII. THIS IS SUPPORTING A WEAK 
SURFACE TROUGH FROM 30N126W TO 27N131W. THIS IS KEEPING THE PRES 
GRADIENT FAIRLY WEAK AND MAINTAINING GENERALLY LIGHT WIND FLOW W 
OF 120W. A MESOSCALE RIDGE IS NOTED IN THE WIND FIELD VIA 
SCATTEROMETER DATA E OF THE SURFACE TROUGH...WITH 15 TO 20 KT NW 
TO N FLOW OFF THE BAJA COAST N OF 23N. ALTIMETER DATA OVER THE 
PAST SEVERAL HOURS NOTED SEAS TO 9 FT OVER THE WATERS W OF 
130W...LIKELY DUE TO PERSISTENT N SWELL. THE WINDS N OF THE AREA 
RESPONSIBLE FOR THE SWELL HAVE BEEN DIMINISHING...AND THE SWELL 
WILL SUBSIDE BELOW 8 FT THROUGH LATE THU. 

FARTHER SOUTH...TRADE WIND FLOW REMAINS RELATIVELY LIGHT DUE THE 
LACK OF SIGNIFICANT SURFACE RIDGING N OF THE AREA. DESPITE 
FAVORABLE DIVERGENCE ALOFT ON THE WESTERN EDGE OF AN UPPER 
ANTICYCLONE...NO SIGNIFICANT CONVECTION IS NOTED ALONG THE 
ITCZ/MONSOON TROUGH W OF 110W DUE TO WEAK TRADE WIND 
CONVERGENCE. 

E OF 110W...LIGHT TO MODERATE SW FLOW PERSISTS MAINLY S OF 12N. 
THIS IS CONVERGING WITH OFFSHORE DRAINAGE FLOW ALONG THE COAST 
TO PRODUCE A FEW AREAS OF CONVECTION OFF MAINLY THE COAST OF 
COSTA RICA AND SOUTHERN NICARAGUA. SUBSIDENT N TO NE FLOW ALOFT 
IS INHIBITING SIGNIFICANT CONVECTION HOWEVER DESPITE HIGH DEEP 
LAYER MOISTURE. 

LOOKING AHEAD...A WEAK PRES PATTERN WILL MAINTAIN LIGHT TO 
MODERATE FLOW OVER THE DISCUSSION AREA THROUGH THE WEEKEND. SEAS 
WILL CONTINUE TO DIMINISH OVERALL...EXCEPT A NEW ROUND OF N 
SWELL WITH SEAS TO 8 FT IS EXPECTED TO PUSH S OF 30N LATE 
SAT...COVERING THE AREA N OF 27N W OF 125W BY LATE SUN.

$$
CHRISTENSEN