000
AXPZ20 KNHC 191008
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1005 UTC THU FEB 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0900 UTC.               

...SPECIAL FEATURES...
GULF OF TEHUANTEPEC GALE WARNING...A TIGHT PRESSURE GRADIENT
BETWEEN HIGH PRES ACROSS THE EASTERN U.S. EXTENDING SW INTO THE
W GULF OF MEXICO...AND RELATIVELY LOW PRES FARTHER SOUTH IN THE
DEEP TROPICS IS SUPPORTING PERSISTENT GALE FORCE WINDS ACROSS
THE GULF OF TEHUANTEPEC. MAXIMUM SUSTAINED WINDS ARE EXPECTED TO
REMAIN NEAR 40 KT UNTIL AFTER SUNRISE THIS MORNING AS THE PRES
GRADIENT STARTS TO RELAX DURING THE PERIOD OF PEAK NOCTURNAL
DRAINAGE FLOW. MAXIMUM SEAS ARE CURRENTLY AROUND 14 TO 15 FT.
WINDS WILL DIMINISH TO MINIMAL GALE FORCE THIS AFTERNOON BUT
WILL PULSE AGAIN TO 40 KT WITH THE NOCTURNAL DRAINAGE FLOW LATE
TONIGHT THROUGH EARLY SAT BEFORE DIMINISHING BELOW GALE FORCE BY
MIDDAY ON SAT. SEAS WILL SUBSIDE TO A MAXIMUM OF 9 FT IN THE
GULF OF TEHUANTEPEC BY THE END OF THE FORECAST PERIOD SAT
EVENING.

GULF OF PAPAGAYO GALE WARNING...THE SAME STRONG RIDGE AFFECTING
THE GULF OF MEXICO IS ALSO PRODUCING A TIGHT PRES GRADIENT
ACROSS CENTRAL AMERICA...AND INITIATED FRESH TO STRONG NE WINDS
ACROSS THE GULF OF PAPAGAYO REGION THIS EVENING. THESE WINDS
HAVE SINCE INCREASED TO GALE FORCE TONIGHT DURING THE NOCTURNAL
MAXIMUM OF DRAINAGE FLOW AND WILL CONTINUE THROUGH LATE MORNING
BEFORE DIMINISHING TO 25-30 KT THIS AFTERNOON. WINDS WILL THEN
PULSE TONIGHT...WITH MAXIMUM SUSTAINED WINDS REACHING GALE
FORCE...AND CONTINUE THROUGH MIDDAY SAT. A LONG FETCH OF FRESH
TO STRONG NE WINDS WILL EXTEND WELL W OF PAPAGAYO TO AS FAR AS
100W EARLY THIS MORNING. THIS SWELL WILL MERGE WITH SWELL FROM
THE GULF OF TEHUANTEPEC TO MAKE FOR A LARGE SWATCH OF SEAS IN
THE 8-12 FT RANGE FROM AROUND 03N-13N BETWEEN 94W-121W FRI AND
SAT.
 
...INTERTROPICAL CONVERGENCE ZONE...
THE ITCZ EXTENDS FROM 05N89W TO 00.5N107W TO 04N128W TO BEYOND
02N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED FROM 06N
TO 12N BETWEEN 112W AND 115W. WIDELY SCATTERED MODERATE
CONVECTION NOTED WITHIN 180 NM N OF ITCZ W OF 124W. 

...DISCUSSION...
A WEAKENING COLD FRONT STRETCHES ACROSS THE NORTHERN GULF OF
CALIFORNIA THROUGH PUNTA EUGENIA TO 25N120W...WHERE IT IS
BECOMING BOTH NEARLY STATIONARY AND ILL DEFINED. THIS FRONT
SHOULD DISSIPATE TODAY. NW SWELL GENERATED BEHIND THIS FRONT
WILL GRADUALLY BRING SEAS OVER 8 FT TO MUCH OF THE NW HALF OF
THE AREA...INCLUDING ALONG THE PACIFIC COAST OF THE BAJA
CALIFORNIA PENINSULA...TODAY THROUGH SAT. SEAS JUST OFF THE BAJA
CALIFORNIA NORTE COAST WILL BE AS HIGH AS 11 FT IN THE WATERS
JUST OFFSHORE LATE TODAY AND EARLY SAT BEFORE BEGINNING TO
SUBSIDE.

WEAK HIGH PRES LIES IN THE WAKE OF THE AFOREMENTIONED COLD
FRONT. THE MOST RECENT SCATTEROMETER PASSES SHOW TRADE WINDS
HAVE DIMINISHED TO GENERALLY 15-20 KT. HIGH PRES WILL BE SLOW TO
BUILD IN ACROSS THE AREA BEHIND THE COLD FRONT AS A SECOND FRONT
IS EXPECTED FAST ON ITS HEELS. THIS FRONT WILL CLIP N WATERS FRI
WITH LITTLE IMPACTS BEFORE WEAKENING AND RETREATING TO THE N. A
NEW FRONT WILL APPROACH NW WATERS ON SAT. SW WINDS WILL INCREASE
TO A FRESH BREEZE AHEAD OF THE FRONT OVER THE NW WATERS SAT
MORNING AND AFTERNOON AS A RESULT. 

GAP WINDS... 
GULF OF PANAMA...STRONG RIDGING N OF THE AREA SHOULD IS DRIVING
A TIGHTENED PRES GRADIENT ACROSS THE GULF OF PANAMA TONIGHT AND
IS EXPECTED TO CONTINUE THROUGH SAT. FRESH TO STRONG N WINDS
CURRENTLY BELIEVED TO BE S-SW OF THE GULF OF PANAMA TO 05N80W
WILL INCREASE TO JUST BELOW GALE FORCE BY MORNING AND WILL
REMAIN 20-30 KT UNTIL SAT AFTERNOON WHEN THE PRES GRADIENT
BEGINS TO WEAKEN. SEAS WILL BUILD TO 9-11 FT THIS MORNING AND
WILL SUBSIDE TO 9 FT LATE SAT AS THE WINDS DIMINISH TO A FRESH
TO STRONG BREEZE. STRONG NORTHERLY WINDS WILL ALSO SPILL ACROSS
PANAMA AND THROUGH MONTIJO BAY DURING THIS TIME...AND SPREAD
TOWARDS THE SW TO WELL OFFSHORE.

$$
STRIPLING