000
AXPZ20 KNHC 171519
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU MAR 17 2016

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.              
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...      

THE ITCZ AXIS EXTENDS FROM 07N87W TO 05N100W TO 03N110W TO
05N125W TO 04N140W. A SMALL CLUSTER OF MODERATE CONVECTION IS
NOTED NEAR 05N94W. A CLUSTER OF MODERATE TO ISOLATED STRONG
CONVECTION IS WITHIN 75 NM N OF AXIS BETWEEN 112W AND 115W.

...DISCUSSION... 
                                              
OVERALL TRANQUIL CONDITIONS PREVAIL ACROSS THE WESTERN FORECAST
WATERS AS A 1019 MB HIGH PRES LOCATED NEAR 29N134W DOMINATES THE
AREA. THIS SYSTEM EXTENDS A RIDGE SE TO BEYOND THE REVILLAGIDO
ISLANDS. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN
THE VICINITY OF THE ITCZ AXIS IS SUPPORTING MODERATE TO LOCALLY
FRESH TRADE WINDS FROM 05N TO 15N W OF 108W AS NOTED PER 
SCATTEROMETER DATA. 

SEAS OF 8-9 FT IN NW SWELL ASSOCIATED WITH A PREVIOUS FRONTAL
SYSTEM ROUGHLY COVER THE WATERS N OF 15N BETWEEN 110W AND 125W
AND S OF 15N W OF 100W. THESE SEA HEIGHTS WILL CONTINUE TO
SUBSIDE TO LESS THAN 8 FT IN ABOUT 24-36 HOURS. HOWEVER...A NEW
COLD FRONT CURRENTLY LOCATED W OF AREA WILL BRING ANOTHER SET OF
LONG PERIOD NW SWELL THAT WILL PROPAGATE ACROSS THE FORECAST
WATERS OVER THE NEXT 48 HOURS REACHING THE AREA W OF A LINE FROM
30N125W TO 20N132W TO 12N140W BY SAT MORNING. EXPECT BUILDING
SEAS UP TO 12-13 FT IN ASSOCIATION WITH THIS SWELL EVENT.

THE ABOVE MENTIONED COLD FRONT IS FORECAST TO ENTER THE FORECAST
REGION TODAY EXTENDING FROM 30N134W TO 25N140W BY FRI MORNING.
FRESH TO STRONG S-SW WINDS ARE EXPECTED AHEAD OF THE FRONT AND
MAINLY W OF A LINE FROM 30N138W TO 28N140W. THIS FRONT IS
FORECAST TO STALL OVER THE NW WATERS LATE FRI INTO SAT...THEN A
NEW COLD FRONT WILL REACH 30N140W BY LATE SAT. THESE FRONTS ARE
FORECAST TO MERGE BY EARLY SUN. AT THAT TIME...THE MERGING FRONT
WILL EXTEND FROM 30N131W TO BEYOND 24N140W. 

LOOKING AHEAD...A RELATIVELY STRONG COLD FRONT IS FORECAST TO
MOVE SE ACROSS THE GULF OF MEXICO AND REACH THE CHIVELA PASS ON
SUN. THE BUILDING HIGH PRESSURE BEHIND THE FRONT WILL INDUCE A
GULF OF TEHUANTEPEC GAP WIND EVENT. CURRENTLY...GALE CONDITIONS
ARE FORECAST FROM SUN EVENING THROUGH TUE MORNING...WITH PEAK
SUSTAINED WINDS POSSIBLY REACHING 40-45 KT DURING THIS EVENT.
WAVE HEIGHTS MAY REACH UP TO 16-17 FT SUN NIGHT AND MON IN THE
GULF OF TEHUANTEPEC. EXPECT ALSO INCREASING WINDS ACROSS THE
GULF OF PAPAGAYO MON NIGHT INTO TUE WITH PEAK SUSTAINED WINDS OF
30 KT AND BUILDING SEAS OF 9-10 FT DOWNSTREAM OF THE GULF.

$$
GR