000
AXPZ20 KNHC 291546
TWDEP 

AXPZ20 KNHC DDHHMM
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC WED APR 29 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC. 

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...AN ELONGATED AREA OF LOW PRES 
EXTENDS FROM SW MEXICO SE TO COASTAL WATERS OF COLOMBIA AND 
PANAMA WHILE HIGH PRESSURE ANCHORED OVER N MEXICO CONTINUES TO 
BUILD OVER THE WESTERN GULF OF MEXICO. THIS PRESSURE PATTERN IS 
LEADING TO A PRESSURE GRADIENT INCREASE N-NW OF THE ISTHMUS OF 
TEHUANTEPEC...RESULTING IN N WINDS 20 TO 25 KT AND SEAS TO 10 FT 
THIS MORNING. THE RIDGE OVER MEXICO WILL CONTINUE TO MOVE E 
DURING THE DAY...THUS TIGHTENING FURTHER THE PRES GRADIENT 
ACROSS THE ISTHMUS TO SUPPORT MINIMAL GALE CONDITIONS IN THE 
GULF OF TEHUANTEPEC STARTING THIS AFTERNOON THROUGH EARLY FRIDAY 
MORNING. SEAS DURING THIS PERIOD WILL BUILD UP TO 13 FT.

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

THE MONSOON TROUGH EXTENDS FROM A 1007 MB LOW NEAR 08N79W TO 
07N100W TO A 1008 MB LOW NEAR 10N117W TO 04N131W. THE ITCZ 
BEGINS NEAR 04N131W AND CONTINUES TO 04N140W. SCATTERED STRONG 
CONVECTION IS WITHIN 90 NM OF 05.5N84W AND 07.5N95W. SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION IS ELSEWHERE FROM 01N TO 
11N BETWEEN 80W AND 103W. SCATTERED MODERATE CONVECTION IS FROM 
01N TO 08N BETWEEN 120W AND 133W. ISOLATED MODERATE CONVECTION 
IS FROM 01N TO 08N W OF 134W. 

...DISCUSSION...    

WATER VAPOR IMAGERY SHOWS A MID-UPPER LEVEL TROUGH EXTENDING 
FROM TEXAS SW TO A BASE OVER EPAC TROPICAL WATERS AND BROAD 
RIDGING ACROSS CENTRAL AMERICA THAT ADVECTS MOISTURE ACROSS 
SOUTHERN MEXICO E OF THE TROUGH. VERY ACTIVE MODERATE TO STRONG 
CONVECTION IS OCCURRING IN THE MONSOON REGION BETWEEN 79W AND 
103W. FARTHER WEST...A NARROW ELONGATED UPPER LEVEL TROUGH 
SUPPORTS A DISSIPATING STATIONARY FRONT NORTH-CENTRAL CALIFORNIA 
SW TO 30N127W TO 25N140W TO NORTH OF THE HAWAIIAN ISLANDS. WATER 
VAPOR IMAGERY DEPICTS VERY DRY AIR SUBSIDING IN THIS REGION... 
THUS RESULTING IN THE LACK OF CONVECTION. NW SWELL BEHIND THE 
FRONT WILL SUBSIDE THURSDAY MORNING. ANOTHER SURGE OF N-NW SWELL 
ASSOCIATED WITH STRONG N WINDS ALONG THE CALIFORNIA COAST WILL 
SWEEP S OF 30N INTO NE PORTION OF THE AREA TONIGHT THROUGH THU 
NIGHT.

LOOKING AHEAD...A VERY LARGE AREA OF CROSS-EQUATORIAL LONG 
PERIOD SW SWELL WILL BEGIN TO AFFECT S AND SE PORTIONS THU NIGHT 
AND FRI WITH SEAS 9-12 FT AND 19-23 SEC PERIOD. THIS SWELL WILL 
REACH THE WEST COAST OF CENTRAL AMERICA THIS WEEKEND...WITH 
LARGE SURF LIKELY FROM PANAMA TO CENTRAL MEXICO.

$$
RAMOS/NELSON