000
AXPZ20 KNHC 230925
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC MON DEC 23 2013

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...

ATTENTION REMAINS FOCUSED ON THE NEXT GULF OF TEHUANTEPEC WIND 
EVENT...FORECAST TO BE THE THIRD STORM FORCE WIND EVENT OF THE 
SEASON. A STORM WARNING IS ALREADY IN EFFECT FOR THIS AREA FROM 
24/0600 UTC TO 24/1800 UTC. IN ADDITION...A GALE WARNING HAS 
BEEN ISSUED BEGINNING THIS AFTERNOON THROUGH THE REMAINDER OF 
THE FORECAST PERIOD. A COLD FRONT CURRENTLY MOVING ACROSS THE 
GULF OF MEXICO HAS REACHED THE WESTERN PART OF THE BAY OF 
CAMPECHE. COLD DENSE AIR BEHIND THE FRONT WILL FUNNEL THROUGH 
THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. NORTHERLY WINDS 
AT 20-30 KT WILL BEGIN TO SURGE INTO THE AREA THIS MORNING AND 
QUICKLY INCREASE TO GALE FORCE IN THE AFTERNOON. THE GALE FORCE 
WINDS THEN QUICKLY ATTAIN STORM INTENSITY DURING THE OVERNIGHT 
HOURS WITH THE ADDED COMPONENT OF NOCTURNAL DRAINAGE FLOW. SEAS 
IN THE GULF OF TEHUANTEPEC WILL RAPIDLY BUILD TO 10 FT BY MON 
AFTERNOON...TO 15 FT MON EVENING...17-19 FT MON NIGHT AND 
REACHING AS HIGH AS 18-20 FT BY TUE MORNING. FRESH TO STRONG 
WINDS WILL EXTEND WESTWARD TO REACH AS FAR AS 108W WITH SEAS TO 
8 FT BY TUE NIGHT. WINDS ARE FORECAST TO DIMINISH BELOW STORM 
FORCE BY TUE AFTERNOON...THEN BELOW GALE FORCE BY WED AFTERNOON.

PLEASE REFER TO THE LATEST NHC/TAFB HIGH SEAS FORECAST UNDER 
AWIPS/WMO HEADERS MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 07N90W TO 06N105W... 
WHERE IT TRANSITIONS TO THE ITCZ TO 08N128W TO 07N140W. 
SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM N OF THE 
ITCZ BETWEEN 122W AND 130W.

...DISCUSSION... 

A NEARLY STATIONARY HIGH PRES OF 1031 MB IS CENTERED N OF THE 
AREA NEAR 40N133W WITH RIDGE EXTENDING SEWD TO NEAR 22N112W. THE 
PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY 
OF THE ITCZ IS PRODUCING A SMALL AREA OF FRESH TO STRONG TRADES  
FROM 12N TO 16N W OF 132W. THE 1031 MB HIGH IS FORECAST TO 
REMAIN NEARLY STATIONARY OVER THE NEXT 24 HRS. A TROUGH IS 
EXPECTED TO DEVELOP ALONG 132-133W TONIGHT. AN AREA OF FRESH TO 
STRONG NE TO E WINDS WILL PERSIST W OF THE TROUGH AXIS COVERING  
ROUGHLY FROM 14N TO 21N W OF 132W TONIGHT...AND N OF 15N W OF 
LINE FROM 22N138W TO 15N132W TUE NIGHT...WHEN THE TROUGH IS 
FORECAST TO BE JUST W OF THE AREA.  

LONG PERIOD NW SWELLS...WITH WAVE PERIODS BETWEEN 18-21 SEC 
ALONG THE LEADING EDGE HAVE REACHED MUCH OF THE FORECAST WATERS 
W OF 110W. THESE SWELLS WILL CONTINUE TO PROPAGATE SEWD COVERING 
MUCH OF THE DISCUSSION AREA W OF 100W BY TONIGHT. THIS SWELL 
EVENT WILL MIX WITH SEAS GENERATING DOWNSTREAM OF THE GULF OF 
TEHUANTEPEC BY TUE MORNING. LATEST WAVEWATCH GUIDANCE SUGGESTS 
THAT THE LEADING EDGE OF YET ANOTHER SET OF LONG PERIOD SWELLS 
BEGINS TO PROPAGATE SEWD ACROSS THE FAR NW PORTION OF THE AREA 
BY TUE EVENING WITH SEAS TO 8 FT JUST NW OF THE AREA. 

WINDS WILL PULSE OVER THE NEXT COUPLE OF DAYS OVER THE GULF OF 
PAPAGAYO. WINDS WILL PEAK NEAR 25 KT DURING THE OVERNIGHT AND 
EARLY MORNING HOURS WITH THE ASSISTANCE OF THE NOCTURNAL 
DRAINAGE FLOW AND SOME ADDED ENHANCEMENT FROM EASTERLY GRADIENT 
FLOW FROM THE CARIBBEAN FUNNELING THROUGH THE GAP IN TYPOGRAPHY 
OF CENTRAL AMERICA. SEAS WILL BUILD TO NEAR 8 FT. 

GULF OF CALIFORNIA...HIGH PRES WILL BUILD ACROSS THE GREAT BASIN 
REGION TODAY WHILE INTENSIFYING. THE PRES GRADIENT BETWEEN THE 
HIGH PRES AND TROUGHING OVER MEXICO WILL STRENGTHEN WINDS OVER 
THE CENTRAL AND NRN GULF OF CALIFORNIA. EXPECT NW WINDS OF 20-25 
KT TODAY AND TONIGHT WITH SEAS BUILDING TO AROUND 6 FT. THE PRES 
GRADIENT THEN RELAXES BY EARLY TUE ALLOWING THESE WINDS TO 
DIMINISH TO 20 KT OR LESS. 
 
$$
GR