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Eastern Pacific Tropical Weather Discussion (Text)



000
AXPZ20 KNHC 290247
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SUN MAR 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC. 

...SPECIAL FEATURES...  

GULF OF TEHUANTEPEC GALE WARNING...A HIGH PRES RIDGE ALONG THE 
EASTERN RANGE OF THE SIERRA MADRE ORIENTALES INTO SOUTHEAST 
MEXICO...AND CONTINUES TO DRIVE STRONG NLY WINDS THROUGH THE 
CHIVELAS PASS AND ACROSS THE GULF OF TEHUANTEPEC. GALE FORCE 
WINDS ACROSS THE GULF OF TEHUANTEPEC AND DOWNWIND TO NEAR 13.5N 
THIS MORNING HAS DIMINISHED TO MINIMAL GALES THIS AFTERNOON... 
BUT WILL INCREASE SLIGHTLY AGAIN THIS EVENING AND TONIGHT... 
BEFORE DECREASING TO LESS THAN GALE FORCE LATE SUNDAY MORNING... 
THEN DECREASE TO 20-25 KT BY SUNDAY AFTERNOON. A MODERATE HIGH 
PRESSURE RIDGE ACROSS THE ENTIRE GULF OF MEXICO WILL AID IN 
NORTHERLY WINDS CONTINUING TO PULSE TO 25-30 KT SUN NIGHT INTO 
EARLY MON MORNING... AND TO 20-25 KT MON NIGHT INTO EARLY TUE 
MORNING...AIDED BY NOCTURNAL DRAINAGE FLOW. SWELL ASSOCIATED 
WITH THIS GAP WIND EVENT WILL SPREAD SOUTHWARD COVERING THE 
WATERS FROM 08N TO 14N BETWEEN 93W AND 103W BY SUN 
AFTERNOON WITH SEAS TO AROUND 9 FT.

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

A MONSOONAL CIRCULATION IS USUALLY NOT PRESENT ACROSS THE 
TROPICAL NE PACIFIC DURING THE LATE WINTER AND EARLY SPRING 
MONTHS. A WEAK TROUGH EXTENDS FROM LOW PRES 1010 MB NEAR 
05.5N78W TO 04N90W...THEN TRANSITIONS TO ITCZ...CONTINUING ON TO 
05.5N105W TO 04N115W TO 10.5N130W TO 06N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION NOTED FROM 03N TO 10N BETWEEN 110W 
AND 113W.  SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 
360 NM N OF ITCZ W OF 127W.

...DISCUSSION...                                                

A 1030 MB HIGH PRES CENTER WAS LOCATED N OF AREA NEAR 35N133.5W 
THIS EVENING AND EXTENDS A RIDGE SE ACROSS THE FORECAST WATERS 
TO NEAR 20N115W. SOUTH OF THE RIDGE...THE PRES GRADIENT BETWEEN 
THE HIGH AND LOWER PRES ALONG THE ITCZ IS RESULTING IN FRESH TO 
STRONG NE TRADEWINDS FROM 09N TO 24N W OF 125W...WHERE SEAS ARE 
8-12 FT IN MIXED NE WIND WAVES AND LONG PERIOD CROSS EQUATORIAL 
SOUTHERLY SWELLS. A MIDDLE TO UPPER LEVEL CYCLONE IS BEGINNING 
TO BECOME CUT OFF FROM ITS PARENT NARROW TROUGH...NEAR 
10N144W...AND AIDING IN DIFFLUENCE ALOFT TO ITS E ACROSS THE 
ZONE OF FRESH TRADES AND DEEP CONVECTION DESCRIBED ABOVE. THE 
AERIAL EXTENT OF THE TRADES WILL DECREASE ON SUN AS HIGH PRES 
DRIFTS SE AND WEAKENS. 

E OF 120W...WINDS GENERALLY REMAIN LIGHT TO MODERATE...AND VERY 
LIGHT E OF 90W...WHERE A SURFACE TROUGH EXTENDS E TO W AS 
DESCRIBED ABOVE. UPPER LEVEL RIDGING ACROSS THE MAJORITY OF THE 
ITCZ IS AIDING IN MAINTAINING CLUSTERS OF DEEP CONVECTION...AND 
IS EXPECTED TO MAINTAIN UNSTABLE CONDITIONS DURING THE NEXT 24 
HOURS THERE.

LONG PERIOD SOUTHERLY SWELL CONTINUES TO DOMINATE MUCH OF THE 
FORECAST WATERS E OF 125W...AND ARE REACHING THE CENTRAL 
AMERICAN AND MEXICAN COASTLINES THROUGH BAJA CALIFORNIA. THESE 
SWELLS ARE GENERATING VERY LARGE AND POWERFUL WAVES...AND 
DANGEROUS CONDITIONS WITHIN THE SURF ZONE TODAY...BUT WILL 
GRADUALLY FADE DURING THE NEXT 24 HRS.

GAP WINDS...

GULF OF PAPAGAYO...EXPECT INCREASING WINDS ACROSS THIS GAP WIND 
REGION BY EARLY SUN MORNING AS HIGH PRES BUILDS ACROSS THE NW 
CARIBBEAN AND NORTHERN CENTRAL AMERICA IN THE WAKE OF A COLD 
FRONT THAT CURRENTLY EXTENDS FROM CENTRAL CUBA TO THE GULF OF 
HONDURAS. WINDS WILL PULSE AGAIN ACROSS THIS AREA EARLY MON 
MORNING. 

$$ 
STRIPLING

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Page last modified: Sunday, 29-Mar-2015 02:47:11 UTC