000
AXPZ20 KNHC 191524
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 19 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.              
 
...SPECIAL FEATURES... 
                                       
GALE WARNING FOR GULF OF TEHUANTEPEC...A GALE WARNING HAS BEEN
POSTED FOR THE GULF OF TEHUANTEPEC BEGINNING SUN AFTERNOON. 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 PRES BEHIND THE FRONT WILL INDUCE A GULF OF TEHUANTEPEC GAP
WIND EVENT. MARINE GUIDANCE SUGGESTS THAT N WINDS OF 20-30 KT
WILL BEGIN EARLY ON SUN...THEN INCREASE TO MINIMAL GALE FORCE BY
EARLY SUN AFTERNOON WITH BUILDING SEAS OF 8 TO 10 FT. WINDS WILL
FURTHER INCREASE TO 40 KT BY SUN NIGHT WITH SEAS BUILDING TO THE
RANGE OF 9-13 FT EARLY SUN NIGHT...AND TO 14-17 FT LATE SUN
NIGHT. BY EARLY MON...THE MAX WINDS MAY REACH 45 KT WITH SEAS
BUILDING FURTHER TO AROUND 19 FT. SEAS OF 9-14 FT ARE FORECAST
TO SPREAD SW FROM THE GULF TO BEYOND 10N100W BY LATE MON. WINDS
ARE FORECAST BY THE COMPUTER MODELS TO BE BELOW GALE FORCE BY
LATE TUE. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO
HEADERS MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS.

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

THE ITCZ AXIS EXTENDS FROM 06N82W TO 05N90W TO 06N110W TO
04N120W TO 03N140W. SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS NOTED FROM 04N TO 07N BETWEEN 82W AND 91W. SIMILAR
CONVECTION CAN BE FOUND WITHIN 90 NM S OF AXIS BETWEEN 117W AND
120W.

...DISCUSSION...

A 1019 MB HIGH IS CENTERED NEAR 28N128W WITH A RIDGE AXIS
EXTENDING SE TO NEAR THE REVILLAGIGEDO ISLANDS. THE OVERALL
PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRES TO THE S
WITHIN THE ITCZ REGION IS SUPPORTING MODERATE TO LOCALLY FRESH
NE TRADES S OF 18N AND W OF 120W...WITH SEAS IN THE 6 TO 9 FT
RANGE BASED ON A COUPLE OF ALTIMETER PASSES. SIMILAR WIND SPEEDS
ARE ALSO NOTED JUST OFF THE BAJA CALIFORNIA PENINSULA DUE TO THE
PRES GRADIENT BETWEEN THE RIDGE AND A TROUGH ANALYZED ALONG THE
NW COAST OF MAINLAND MEXICO. SEAS ACROSS THE PACIFIC WATERS OF
BAJA ARE GENERALLY RANGED 5-7 FT IN NW SWELL. 

A FRONT REMAINS NEARLY STATIONARY OVER THE NW CORNER OF THE
FORECAST AREA AND EXTENDS FROM 30N135W TO 26N140W. AT THE SAME
TIME...A COLD FRONT IS APPROACHING FROM THE W AND CURRENTLY
CROSSES 30N144W. THESE FRONTS ARE FORECAST TO MERGE TONIGHT OVER
THE NW WATERS. THEN...THE MERGING FRONT WILL EXTEND FROM 30N131W
TO 23N140W BY EARLY SUN MORNING. WINDS OF 20 KT OR LESS ARE
EXPECTED ON EITHER SIDE OF THE FRONT. EXISTING NW SWELL OF 8 TO
13 FT ASSOCIATED WITH THE STATIONARY FRONT WILL PROPAGATE S-SE
AND GRADUALLY BEGIN TO SUBSIDE THROUGH SUN...HOWEVER THE
APPROACHING FRONT WILL BRING ANOTHER PULSE OF NW SWELL WITH SEAS
ONCE AGAIN BUILDING UP TO 16-17 FT ACROSS THE NW WATERS BY LATE
SUN.

A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25 KT NE WINDS IS
SUGGESTED BY MODEL GUIDANCE TO TAKE PLACE MON MORNING AS HIGH
PRES BUILDS ACROSS THE WESTERN CARIBBEAN AND NORTHERN CENTRAL
AMERICA. THE AERIAL EXTENT OF THE FRESH TO STRONG WINDS IS
FORECAST TO INCREASE FROM 08.5 TO 11.5N E OF 91W-92W BY EARLY
TUE MORNING. 

$$
GR