000
AXPZ20 KNHC 150314
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC SAT JUN 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...TROPICAL WAVES...                                             
A TROPICAL WAVE EXTENDS ALONG 94W N OF 11N BASED ON A RECENT 
OSCAT PASS THAT SHOWS THE WIND SHIFT ASSOCIATED WITH THE WAVE 
AXIS. THE WAVE IS STILL WELL DEPICTED IN THE MOISTURE PRODUCT 
...BUT CONVECTION ASSOCIATED WITH IT IS LIMITED AT THIS MOMENT. 
THE TROPICAL WAVE WILL CONTINUE TO INTERACT WITH THE MONSOON 
TROUGH AND WEAKEN AS IT MOVES WESTWARD TO NEAR 98W BY SAT 
EVENING. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
MONSOON TROUGH AXIS EXTENDS FROM 09N76W ACROSS PANAMA AND COSTA 
RICA TO 10N86W TO 10N100W TO 11N120W TO A 1010 MB LOW PRES NEAR 
09N125W. ITCZ AXIS EXTENDS FROM LOW PRES TO 08N140W. CLUSTERS OF 
MODERATE TO STRONG CONVECTION ARE S OF TROUGH AXIS TO 07N AND E 
OF 86W. CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION WITHIN 
75 NM SW OF LINE FROM 08N91W TO 09N92W. ISOLATED MODERATE TO 
STRONG CONVECTION FROM 09N TO 13N BETWEEN 96W AND 100W...AND 
FROM 06N TO 10N BETWEEN 100W AND 107W. 

...DISCUSSION...                                                
ALOFT...W TO SW UPPER LEVEL WINDS...IN ASSOCIATION WITH A BROAD 
UPPER LEVEL TROUGH...DOMINATE MOST OF THE FORECAST AREA N OF 
20N...INCLUDING THE BAJA CALIFORNIA PENINSULA AND NW MEXICO. AN 
ANTICYCLONE REMAINS CENTERED OVER WEST-CENTRAL MEXICO NEAR 
19N102W WITH AN ASSOCIATED RIDGE EXTENDING SE ALONG THE COAST OF 
MEXICO TO NEAR 12N90W. A DIFFLUENT PATTERN ALOFT ASSOCIATED WITH 
THIS RIDGE IS HELPING TO INDUCE CONVECTION ACROSS PARTS OF 
CENTRAL MEXICO. ANOTHER RIDGE EXTENDS FROM THE SAME ANTICYCLONE 
TO THE N TOWARDS TEXAS. TO THE EAST...AN UPPER LEVEL TROUGH OVER 
THE NW CARIBBEAN HAS ITS BASE NEAR THE PACIFIC COASTS OF EL 
SALVADOR AND HONDURAS. ANOTHER RIDGE DOMINATES THE REMAINDER OF 
THE FORECAST AREA HELPING TO SUPPORT MODERATE TO STRONG 
CONVECTION OVER PARTS OF PANAMA AND COSTA RICA AND THE PACIFIC 
REGIONAL WATERS. 
 
A WEAK 1010 MB LOW PRES REMAINS EMBEDDED WITHIN THE MONSOON 
TROUGH NEAR 09N125W. VISIBLE SATELLITE IMAGERY SHOWS A SWIRL OF 
LOW CLOUDS ASSOCIATED WITH THIS LOW PRES WHICH IS EXPECTED TO 
REMAIN WEAK WHILE IT DRIFTS WESTWARD DURING THE NEXT 24 HOURS. 
FARTHER WEST...A WEAK SURFACE TROUGH IS ANALYZED N OF THE ITCZ 
ALONG 133W FROM 09N TO 14N. AN INVERTED-V SHAPE TYPE LOW LEVEL 
CLOUD SIGNATURE WAS OBSERVED IN THE LAST VISIBLE SATELLITE 
IMAGERY WITH A SWIRL OF LOW LEVEL CLOUDS ALONG THE TROUGH AXIS 
NEAR 11N. THIS TROUGH COINCIDES WITH A MAXIMUM IN DEEP LAYER 
MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER. NE WINDS OF 15-20 
KT AND SEAS TO 8 FT ARE SEEN MAINLY AHEAD OF THE TROUGH THAT IS 
FORECAST TO MOVE WWD WITH THESE ASSOCIATED MARINE CONDITIONS 
DURING THE NEXT 24-48 HOURS. 

HIGH PRES LOCATED WELL NW OF THE DISCUSSION AREA EXTENDS A RIDGE 
SE TO NEAR 22N114W. A TIGHT PRES GRADIENT BETWEEN THE RIDGE AND 
GENERALLY LOWER PRES OVER THE U.S. WESTERN COAST IS SUPPORTING 
FRESH TO STRONG WINDS ALONG THE NORTH-CENTRAL COAST OF 
CALIFORNIA. NW TO N SWELLS OF 8 TO 9 FT RELATED TO THESE WINDS 
AND CONFIRMED BY AN EARLIER ALTIMETER PASS CONTINUE TO PROPAGATE 
ACROSS THE NORTH WATERS MAINLY N OF 26N BETWEEN 119W AND 129W. 
SEAS ARE EXPECTED TO SUBSIDE TO 8 FT OR LESS IN ABOUT 24 HOURS 
AS THE PRES GRADIENT RELAXES. 

LONG PERIOD CROSS EQUATORIAL SW SWELLS...WITH LEADING EDGE 
PERIOD OF 18-19 SECONDS HAVE REACHED MOST OF THE COASTLINE OF 
CENTRAL AMERICA AND MEXICO BRINGING ROUGH SURF CONDITIONS TO 
THOSE COASTS. 

$$ 
GR