000
AXPZ20 KNHC 172155
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
2205 UTC TUE FEB 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2100 UTC.               

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...A TIGHT PRESSURE GRADIENT
BETWEEN HIGH PRES N OF THE AREA AND RELATIVELY LOW PRES FARTHER
SOUTH IN THE DEEP TROPICS IS SUPPORTING PERSISTENT GALE FORCE
WINDS IN THE GULF OF TEHUANTEPEC. THE PRES GRADIENT WILL
INCREASE THIS EVENING AS THE HIGH PRES N OF THE AREA BUILDS.
WINDS WILL INCREASE IN RESPONSE AND ARE EXPECTED TO BE JUST SHY
OF STORM FORCE THU MORNING DURING THE PERIOD OF PEAK NOCTURNAL
DRAINAGE FLOW. SEAS WILL BUILD AS HIGH AS 15-17 FT. WINDS WILL
PULSE BACK DOWN TO A MINIMAL GALE BY MIDDAY THU...INCREASE TO AS
HIGH AS 40 KT FRI MORNING...AND DIMINISH AGAIN TO A MINIMAL GALE
BY MIDDAY FRI. THE NE SWELL FROM THE GULF OF TEHUANTEPEC AND THE
GULF OF PAPAGAYO WILL GENERATE COMBINED SEAS OVER 8 FT ACROSS A
LARGE SWATH OF THE PACIFIC GENERALLY FROM 03N-13N BETWEEN 90W
AND 121W BY THE END OF THE FORECAST PERIOD FRI AFTERNOON. 
 
...INTERTROPICAL CONVERGENCE ZONE...

THE ITCZ AXIS WAS ANALYZED FROM 02N88W TO 03N110W TO
05N120W...THEN RESUMES FROM 04N124W TO 02N130W TO 01N140W.
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN
210 NM EITHER SIDE OF THE AXIS BETWEEN 105W-120W. A TROUGH WAS
ANALYZED FROM 08N121W TO 02N124W. SCATTERED MODERATE CONVECTION
WAS WITHIN 90 NM EITHER SIDE OF THE TROUGH FROM 04N-06N.

...DISCUSSION...

A COLD FRONT STRETCHES ACROSS NW WATERS FROM 32N129W TO 30N131W
TO 25N140W. A FRESH TO STRONG NW BREEZE BEHIND THE FRONT WAS
OBSERVED BY THE 1924 UTC ASCAT PASS W OF THE FRONT N OF 28N.
THESE WINDS WILL PERSIST THROUGH THIS EVENING AND DIMINISH
OVERNIGHT WHEN THE FRONT BEGINS TO DISSIPATE. THE SWELL WILL
CONTINUE TO PROPAGATE SOUTHEASTWARD...WITH SEAS OVER THE
FORECAST AREA EXPECTED TO PEAK AROUND 12-16 FT ON THU N OF 28N
BETWEEN 127W-137W BEFORE SUBSIDING TO A MAXIMUM OF 12 FT NEAR
30N121W FRI AFTERNOON. 

HIGH PRES OVER THE NORTHERN WATERS HAS WEAKENED IN ADVANCE OF
THE AFOREMENTIONED COLD FRONT. THE MOST RECENT ASCAT PASSES SHOW
TRADE WINDS HAVE DIMINISHED BELOW A FRESH TO STRONG BREEZE. HIGH
PRES WILL BE SLOW TO BUILD IN BEHIND THE COLD FRONT AS A SECOND
FRONT IS EXPECTED FAST ON ITS HEELS. THIS FRONT WILL CLIP NW
WATERS FRI WITH LITTLE FANFARE. 


GAP WINDS...

GULF OF PAPAGAYO...WINDS AND SEAS ARE BELIEVED TO HAVE
TEMPORARILY DIMINISHED IN THE GULF OF PAPAGAYO BELOW THE
ADVISORY CRITERIA. HIGH PRES WILL BUILD MARKEDLY N OF THE AREA
BY EARLY THU MORNING. THE TIGHTENED PRES GRADIENT SHOULD
INCREASE WINDS TO NEAR GALE FORCE DURING THE NOCTURNAL MAXIMUM
OF DRAINAGE FLOW WHILE THE AREAL EXTENT OF THE FRESH TO STRONG
NE WINDS SPREADS WELL DOWNWIND OF PAPAGAYO TO NEAR 07N96W THU.
SEAS WILL BUILD AS HIGH AS 8-10 FT. WINDS AND SEAS SHOULD REMAIN
ABOVE ADVISORY CRITERIA THU AFTERNOON AND EVENING AND WILL
INCREASE OVERNIGHT. WINDS MAY REACH GALE FORCE DURING THE PERIOD
OF NOCTURNAL DRAINAGE FLOW FRI MORNING. THE FORECAST MAY BE
UPDATED TO REFLECT A GALE WARNING HERE ON THE NEXT PACKAGE IF
THE MODELS REMAIN STRONG. 

GULF OF PANAMA...THE AFOREMENTIONED INCREASE IN RIDGING N OF THE
AREA SHOULD DRIVE A STRONGER PRES GRADIENT ACROSS THE GULF OF
PANAMA AS WELL. FRESH TO STRONG N WINDS ARE EXPECTED S OF THE
GULF OF PANAMA TO 05N BEGINNING EARLY THU MORNING. THESE FRESH
TO STRONG WINDS ARE EXPECTED TO DIMINISH BY THU AFTERNOON ONLY
TO RETURN THU EVENING THROUGH FRI AFTERNOON WHEN THEY SHOULD
REACH AS FAR S-SW AS 02N84W.

$$
SCHAUER