000
AXPZ20 KNHC 252135
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                        
2205 UTC MON MAR 25 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2030 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
THE MONSOON TROUGH IS PRESENTLY NOT IDENTIFIABLE. ITCZ AXIS 
EXTENDS FROM 07N85W TO 01N115W TO BEYOND 03N140W. SCATTERED 
MODERATE ISOLATED STRONG S OF 02N BETWEEN 112W AND 118W...AND  
WITHIN 140 NM N OF THE AXIS BETWEEN 122W AND 126W.

...DISCUSSION...                                             

GAP WINDS...A VERY TIGHT PRES GRADIENT ACROSS THE ISTHMUS OF 
TEHUANTEPEC DUE TO STRONG HIGH PRES BUILDING SWD OVER THE FAR 
WESTERN GULF OF MEXICO IS INDUCING STRONG NLY FLOW THROUGH THE 
CHIVELA PASS...AND INTO THE GULF OF TEHUANTEPEC AS NOTED BY AN 
ARC CLOUD FEATURE CURRENTLY PROPAGATING S AND SW AWAY FROM THE 
GULF. THE EDGE OF AN 1522 UTC HIGH RESOLUTION ASCAT PASS 
CAPTURED AN AREA OF 20-25 KT WINDS IN THE GULF OF TEHUANTEPEC. 
WINDS ARE FORECAST TO GRADUALLY INCREASE TO 35 KT TONIGHT...AND 
TO 40 KT OVERNIGHT ON TUE AS COLD DENSE AIR ATTRIBUTED TO THE 
STRONG HIGH PRES SURGES S THROUGH ISTHMUS OF TEHUANTEPEC AND 
ACROSS THE GULF. SEAS IN THE GULF OF TEHUANTEPEC ARE FORECAST TO 
BUILD TO 12 FT BY LATE TONIGHT...AND TO AROUND 16 FT OVERNIGHT 
ON TUE WHEN THE STRONGEST WINDS ARE EXPECTED. THE PRES GRADIENT 
IS FORECAST TO BEGIN TO SLACKEN LATE WED INTO THU ALLOWING FOR 
THE GALE CONDITIONS TO DIMINISH LATE THU MORNING INTO EARLY THU 
AFTERNOON.

INCREASING TRADE WINDS OVER THE CARIBBEAN REGION ARE FORECAST TO 
EXTEND INTO THE GULF OF PAPAGAYO EARLY WED MORNING...WHEN 
SURFACE WINDS ARE EXPECTED TO REACH 20-25 KT WITH BUILDING SEAS 
TO AROUND 8 FT.
 
A COLD FRONT IS APPROACHING THE FAR NW WATERS OF THE DISCUSSION 
AREA. IT IS FORECAST TO SLOWLY MOVE SE ACROSS THE NW WATERS WED 
AND THU WHILE WEAKENING. BESIDES THE WIND SHIFT ASSOCIATED WITH 
THE FRONT...NO SIGNIFICANT IMPACT ON WINDS AND SEAS IS EXPECTED 
FROM IT. A REINFORCING COLD FRONT WILL THEN REACH 30N140W BY THU 
MERGING WITH THE MAIN FRONT. THE MERGED FRONT WILL EXTEND FROM 
31N131W TO 23N140W THU EVENING FOLLOWED BY FRESH TO STRONG WINDS 
AND BUILDING SEAS TO AROUND 9 FT. 

A 1022 MB HIGH PRES LOCATED NEAR 29N133W EXTENDS A RIDGE SE TO 
NEAR 20N108W. GENTLE TO MODERATE WINDS ARE NOTED PER THE MOST 
RECENT SCATTEROMETER DATA N OF 20N UNDER THE INFLUENCE OF THIS 
SYSTEM. WINDS SLIGHTLY INCREASE TO 15-20 KT  ON THE SOUTHERN 
PERIPHERY OF THE RIDGE. THIS WEAK HIGH PRES WILL CONTINUE OVER 
MUCH OF THE DISCUSSION AREA THROUGH THE NEXT 48 HRS ALLOWING FOR 
RATHER LIGHT WINDS THROUGHOUT.

AN AREA OF 8 FT SEAS IN MIXED NE AND NW SWELL IN NOTED WITHIN 
THE TRADE WINDS FROM 07N TO 10N W OF 132W. THESE SWELLS ARE 
FORECAST BY WAVEWATCH MODEL GUIDANCES TO GRADUALLY SUBSIDE TO 
LESS THAN 8 FT BY 24 HRS.

$$
GR