000
AXPZ20 KNHC 200951
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAR 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0900 UTC.              
 
...SPECIAL FEATURES...                                         
A COLD FRONT HAS MOVED WEST OF THE ISTHMUS OF TEHUANTEPEC ACROSS
SOUTHERN MEXICO WITH NORTHERLY FLOW THROUGH THE GULF OF
TEHUANTEPEC REGION TO BEGIN THIS MORNING AROUND 20/1200 UTC.
WINDS ARE EXPECTED TO RAPIDLY INCREASE THROUGH THE CHIVELA PASS
AS A STRONG PRESSURE GRADIENT ACROSS EASTERN MEXICO AND THE SW
GULF OF MEXICO INDUCES GALE FORCE WINDS BY SUN AFTERNOON LASTING
THROUGH TUE AFTERNOON. MAXIMUM WINDS ARE EXPECTED TO PEAK AROUND
40 TO 45 KT BY SUN NIGHT AND PERSIST THROUGH TUE MORNING. SEAS
WILL BUILD RAPIDLY IN RESPONSE TO THE WIND FIELD WITH SEAS
GREATER THAN 15 FT EXPECTED SUN NIGHT LATE THROUGH TUE
MORNING...PEAKING AROUND 21 FT NEAR 14N96W ON MON AFTERNOON. 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 04N92W TO 06N107W TO 03N128W TO
03N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS
FROM 02N TO 06N BETWEEN 112W AND 118W...AND FROM 02N TO 06N
BETWEEN 127W AND 138W.

...DISCUSSION...                                           
WATER VAPOR IMAGERY SHOWS A LARGE DEEP LAYER CYCLONIC VORTEX
WELL TO THE NW OF THE DISCUSSION AREA NEAR 48N148W WITH AN
ASSOCIATED NEGATIVELY-TILTED SHORTWAVE TROUGH IN THE VICINITY OF
39N134W. THE SHORTWAVE SUPPORTS A COLD FRONT EXTENDING FROM
31N133W TO 28N140W. THIS FRONT IS EXPECTED TO MERGE WITH AN
EXISTING DISSIPATING COLD FRONT TO ITS SOUTHEAST DURING THE NEXT
12 HOURS. WHILE THE OVERALL WIND FIELD ASSOCIATED WITH THE
REINFORCING COLD FRONT REMAINS 20 KT OR LESS...SEAS RANGING FROM
12 TO 16 FT ARE EXPECTED TO BUILD IN FROM THE NW AS A NEW PULSE
OF NW SWELL IS EXPECTED TO INFLUENCE A LARGE PORTION OF THE NW
CORNER OF THE DISCUSSION AREA THROUGH TUE. NW SWELL FROM THE
PREVIOUS FRONT WILL CONTINUE SPREADING SE AND GRADUALLY
SUBSIDE GENERALLY REMAINING W OF 120W.  

ELSEWHERE AT THE SURFACE...A 1020 MB HIGH IS ANALYZED AT 27N130W
WITH A RIDGE AXIS EXTENDING SE TO NEAR 19N110W. THE OVERALL PRES
GRADIENT BETWEEN THE RIDGE AND LOWER PRES TO THE S WITHIN THE
ITCZ REGION IS SUPPORTING MODERATE TO OCCASIONAL FRESH NE TRADES
FROM 06N-17N W OF 121W WITH SEAS RANGING FROM 6 TO 8 FT. THE
TRADES ARE EXPECTED TO VARY LITTLE DURING THE NEXT 48 HOURS...
HOWEVER AS MENTIONED ABOVE...SEAS WILL SIGNIFICANTLY BUILD AS NW
SWELL PROPAGATES S-SE THROUGH THE WESTERN HALF OF THE AREA.

OTHER GAP WINDS... 
A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25 KT NE WINDS IS
FORECAST TO MATERIALIZE BY 21/1200 UTC AND PULSE EACH MORNING
THROUGH THU.

$$
HUFFMAN