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000
AXPZ20 KNHC 270318
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI FEB 27 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 0315 UTC.


...SPECIAL FEATURES...

GULF OF TEHUANTEPEC...NORTHERLY WINDS ARE EXPECTED TO SURGE THROUGH THE GULF OF TEHUANTEPEC AT 20-25 KT LATE TONIGHT... AND REACH MINIMAL GALE FORCE ON FRI EVENING AND PERSIST THROUGH SUNRISE ON SAT...WITH SEAS BUILDING TO ABOUT 12 FT NEAR 14.5N95W ON SAT MORNING. GUIDANCE INDICATES ANOTHER BRIEFLY SURGE TO GALE FORCE LATE SAT NIGHT THEN THE GRADIENT WILL SUPPORT MOSTLY 20-25 KT NORTHERLY WINDS THROUGH LATE MON MORNING...THEN DIMINISHING BELOW 20 KT BY MON EVENING.


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

A LOW LEVEL TROUGH EXTENDS SW FROM THE PACIFIC COAST OF COSTA RICA TO 06N95W WHERE SCATTEROMETER WINDS INDICATE THAT THE ITCZ FORMS AND THEN CONTINUES WNW TO 08N115W...THEN DIPS SW TO 07N130W...THEN TURNS NW AN EMBEDDED TROUGH DEPICTED IN SCATTEROMETER DATA NEAR 09N131W...THEN THE ITCZ CONTINUE W TO BEYOND 07N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 150 NM EITHER SIDE OF A LINE FROM 11N112W TO 09N123W TO 12N128W.


...DISCUSSION...

AN UPPER CYCLONE IS FILLING W OF THE AREA NEAR 17N147W WITH ITS CYCLONIC ENVELOP EXTENDING E INTO THE DISCUSSION AREA FROM 08- 23N W OF 130W. ONLY A FEW SHOWERS ARE INTERMITTENTLY ENHANCED WITHIN THIS AREA. AN UPPER RIDGE EXTENDS W FROM OVER COLOMBIA ACROSS THE TROPICS TO A CREST NEAR 13N122W. UPPER LEVEL DIFFLUENCE UNDER THE W PORTION OF THIS RIDGE...AND TO THE E OF THE UPPER CYCLONE...IS ENHANCING THE CONVECTION PREVIOUSLY DESCRIBED ALONG THE ITCZ. THE DENSE DEBRIS MOISTURE FROM THIS CONVECTION IS ADVECTED N AND NE...CONCENTRATING INTO INTO A 270 NM WIDE PLUME THAT CONTINUES ENE ACROSS NORTHERN MEXICO AND THE NORTHERN GULF OF MEXICO.

A SURFACE RIDGE EXTENDS FROM 32N137W TO 13N105W. A SMALL AREA OF EASTERLY TRADES SW OF THE RIDGE HAVE DIMINISHED TO 20 KT OR LESS. NW SWELLS HAVE BEEN MIXING WITH EASTERLY TRADE WIND SWELL RESULTING IN COMBINED SEAS OF 7-9 FT ACROSS MOST OF PACIFIC WATERS W OF 130W. THE SWELLS WILL GRADUALLY SUBSIDE ON FRI WITH COMBINED SEAS SUBSIDING BELOW 8 FT BY EARLY SAT. NORTHERLY WINDS TO THE NE OF THE RIDGE WILL INCREASE TO 20-25 KT WITH SEAS 8-11 FT ACROSS THE DISCUSSION WATERS N OF 28N BETWEEN 118-130W EARLY TONIGHT. THE WINDS WILL DIMINISH TO NW AT 15-20 KT LATE FRI AS THE N-N SWELLS REACH THE PACIFIC COAST OF THE NORTHERN BAJA PENINSULA IN THE FORM OF 6-8 FT SEAS. THESE MODERATE SEAS ARE EXPECTED TO SUBSIDE TO 5-7 FT ON SAT.

GULF OF CALIFORNIA...LIGHT AND VARIABLE WINDS CURRENTLY OBSERVED ACROSS THE GULF WATERS ARE EXPECTED TO GRADUALLY BECOME S-SW ON FRI...INCREASE TO 20-25 KT OVER THE NORTHERN GULF ON FRI NIGHT THROUGH SAT NIGHT...THEN RELAX TO 10-15 KT AHEAD OF A WEAK TROUGH ARRIVING IN THE NORTHERN GULF ON SUN NIGHT. THE TROUGH WILL PASS THROUGH THE CENTRAL GULF OF CALIFORNIA ON MON NIGHT WITH ONLY A 5-10 KT SW-NW WIND SHIFT.

GULF OF PAPAGAYO...NOCTURNAL 20-25 KT NE SURGES ARE EXPECTED TO RESUME ON FRI NIGHT...WITH A SIGNIFICANT EVENT ON MON NIGHT.

$$ NELSON

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