000
AXPZ20 KNHC 012150
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN DEC 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...SPECIAL FEATURE...

GULF OF TEHUANTEPEC...MINIMAL GALE CONDITIONS AT 1800 UTC WILL 
DIMINISH TO 20-30 KT WITHIN 30 NM EITHER SIDE OF A LINE FROM 
16N95W TO 14N96W BY SUNSET TODAY...WHILE ASSOCIATED SEAS 8-13 FT 
WILL SUBSIDE TO 7-10 FT THIS EVENING. ONE LAST NORTHERLY SURGE 
OF 15-20 KT IS EXPECTED LATE TONIGHT THROUGH SUNRISE ON MON. 
THEREAFTER WINDS IN THE GULF OF TEHUANTEPEC WILL BECOME LIGHT 
AND SOUTHERLY THROUGH LATE FRI.  

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

THE MONSOON TROUGH EXTENDS NW FROM THE COLOMBIAN COAST AT 07N77W 
TO 06N79W...THEN TURNS ABRUPTLY NW ALONG THE PACIFIC COAST OF 
PANAMA TO THE PACIFIC COAST OF COSTA RICA AT 09N84W...THEN TURNS 
SW TO 05N95W...THEN NW TO 06N98W WHERE SCATTEROMETER WINDS 
INDICATE A TRANSITION TO AN ITCZ. THE ITCZ CONTINUES NW TO 11N115W
WHERE IT LOSES IDENTITY IN A DEEP LAYERED TROUGH DOMINATING THE 
DISCUSSION AREA BETWEEN 115-125W. SCATTEROMETER WINDS DETECT THE 
ITCZ REFORMING NEAR 12N126W...AND EXTENDING SW TO BEYOND 08N140W.

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE 
MONSOON TROUGH WITHIN 30 NM OF 06N91W...AND ALONG THE EASTER 
SEGMENT OF THE ITCZ WITHIN 30 NM EITHER SIDE OF A LINE FROM 
07N101W TO 10N111W. SIMILAR CONVECTION IS OBSERVED WITHIN 60 NM 
EITHER SIDE OF A LINE FROM 16N123W TO 12N122W TO 06N133W TO 
06N140W.

SCATTERED MODERATE TO STRONG CONVECTION ACCOMPANIED BY FREQUENT 
LIGHTNING IS OBSERVED WITHIN 90 NM OF 18N117W ASSOCIATED WITH 
A TROUGH EXTENDING FROM 14N121W TO 20N115W.

...DISCUSSION...

THE SURFACE REFLECTION OF A DEEP LAYERED TROUGH EXTENDS FROM 
12N126W TO 27N127W. MODEL GUIDANCE IS IN AGREEMENT THAT A 1010 
MB SURFACE LOW WILL SOON DEVELOP ALONG THE TROUGH NEAR 21N129W. 
THE GRADIENT IS ALREADY SUPPORTING NE-E WINDS AT 20-30 KT ACROSS 
THE DISCUSSION WATERS N OF 20N W OF 125W....WITH LONG PERIOD NW 
AND SE SWELL MIXING WITH THE ASSOCIATED NE SWELL ACROSS THE 
DISCUSSION AREA W OF 115W. THE SURFACE LOW IS FORECAST TO MOVE W 
AND STALL NEAR 21N132W ON MON...WITH THE GRADIENT THEN BEGINNING 
TO RELAX TO THE NW OF THE LOW. THE LOW WILL GRADUALLY DISSIPATE 
THROUGH WED WITH THE NE FLOW DIMINISHING TO 15-20 KT ACROSS THE 
SUBTROPICAL WATERS BY LATE EARLY WED.

GULF OF PAPAGAYO...CURRENTLY N-NE 15-20 KT WINDS ARE BLOWING 
THROUGH AND DOWNSTREAM OF THE WITHIN 60 NM EITHER SIDE OF A LINE 
FROM 11N86W TO 09N90W...WITH SEAS OF 6-8 FT. THE NE FLOW IS 
EXPECTED TO DIMINISH TO 10-15 KT THIS EVENING AND INCREASE TO 
ONLY 15-20 KT AGAIN LATE TONIGHT INTO MON MORNING. GUIDANCE 
INDICATES THAT THE NEXT NE 15-20 KT EVENT WILL OCCUR LATE THU 
NIGHT. 

GULF OF CALIFORNIA...NW WINDS CURRENTLY AT 20-25 KT ACROSS THE 
CENTRAL GULF WATERS BETWEEN 25-28N WILL DIMINISH LATE TONIGHT TO 
10-15 KT. LIGHT AND VARIABLE WINDS ARE EXPECTED ACROSS THE 
ENTIRE GULF ON MON NIGHT...GRADUALLY BECOMING SOUTHERLY OVER THE 
NORTHERN GULF WATERS IN ADVANCE OF AN APPROACHING COLD FRONT. 
THE WEAK COLD FRONT WILL PASS ACROSS THE NORTHERN GULF WATERS ON 
MON NIGHT AND TUE. SEAS ARE EXPECTED TO BUILD TO A MAX OF 4 FT 
IN EXPOSED GULF WATERS N OF 30N BEHIND THE FRONT. 
 
$$
NELSON