000
AXPZ20 KNHC 122112
TWDEP 

TROPICAL WEATHER DISCUSSION                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC SAT APR 12 2014

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 
2100 UTC. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 07N91W WHERE LOW LEVEL 
WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 04.5N98W TO 
06N107W TO 06N122W TO BEYOND 01N132W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 150 NM N OF ITCZ 
BETWEEN 96W AND 104W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 180 NM N AND 60 NM S OF ITCZ BETWEEN 
107W AND 122W. 

...DISCUSSION...                                                

THE SURFACE LOW OVER THE NW WATERS HAS WEAKENED INTO A TROUGH 
AND WILL FURTHER DAMPEN OUT TONIGHT. THIS LOW PRESSURE AREA HAD 
DISRUPTED THE SUBTROPICAL HIGH AND KEPT TRADEWINDS IN THE LIGHT 
TO MODERATE RANGE OVER THE AREA. HIGH PRESSURE HAS STARTED TO 
BUILD ACROSS THE NORTHERN WATERS...AND HAS TIGHTENED THE 
PRESSURE GRADIENT ENOUGH TO FRESHEN TRADES OVER THE 
AREA...ESPECIALLY N OF THE ITCZ TO NEAR 15N AND W OF 125W. 
RECENT ALTIMETER PASSES DEPICT SEAS TO 8 FT OVER THIS AREA. THE 
RIDGE WILL REMAIN OVER THE NORTHERN WATERS TO MAINTAIN THE FRESH 
TRADES AND SEAS TO 8 FT THROUGH AT LEAST MON AFTERNOON. 

A SHARP UPPER TROUGH EXTENDS FROM SOUTHERN MEXICO SW TO NEAR 
00N120W. UPPER FORCING RELATED TO THE TROUGH IS HELPING MAINTAIN 
ACTIVE CONVECTION ALONG THE ITCZ AS MENTIONED ABOVE. THE UPPER 
TROUGH WILL PERSIST OVER THE NEXT SEVERAL DAYS. 
 
SEAS TO 9 FT CONTINUE S OF 10N BETWEEN 98W AND 125W AND S OF 02N 
BETWEEN 92W AND 98W. THESE SEAS CONSIST OF RESIDUAL SWELL FROM 
THE PREVIOUS GULF OF TEHUANTEPEC AND GULF OF PAPAGAYO GAP WIND 
EVENTS AS WELL AS LONG PERIOD SW AND SE SWELL. SEAS OVER THIS 
AREA WILL SLOWLY SUBSIDE OVER THE NEXT COUPLE OF DAYS. BY MON 
AFTERNOON SEAS TO 8 FT WILL BE FOUND MAINLY FROM 00N TO 03.4S 
BETWEEN 97W AND 120W. 

LATEST SCATTEROMETER PASS INDICATES WINDS OVER THE GULF OF 
PAPAGAYO HAVE DIMINISHED TO 20 KT OR LESS. WINDS WILL PULSE TO 
25 KT OVERNIGHT WITH THE ADDED COMPONENT OF NOCTURNAL DRAINAGE 
FLOW BEFORE ONCE AGAIN DIMINISHING TO 20 KT OR LESS BY SUN 
AFTERNOON. THE STRONG TRADE WIND FLOW SUPPORTING THE GAP WINDS 
WILL DIMINISH SUNDAY...ALLOWING ONLY MODERATE TO FRESH GAP WIND 
FLOW SUN NIGHT INTO MONDAY MORNING. 

LOOKING AHEAD...WINDS OVER THE GULF OF TEHUANTEPEC WILL REMAIN 
FAIRLY LIGHT THROUGH AT LEAST TUESDAY. A COLD FRONT IS EXPECTED 
TO MOVE OFF THE COAST OF TEXAS INTO THE GULF OF MEXICO MON 
NIGHT. THE FRONT WILL REACH THE BAY OF CAMPECHE TUE WITH WINDS 
INCREASING OVER THE GULF OF TEHUANTEPEC TUE AFTERNOON. WINDS 
ASSOCIATED WITH THIS GAP WIND EVENT MAY REACH GALE FORCE TUE 
NIGHT.  

$$ 
AL