000
AXPZ20 KNHC 300958
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC MON NOV 30 2015

UPDATED TO INCLUDE CONVECTION OVER CENTRAL WATERS AND MENTION
OF SURFACE TROUGHS

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...
 
GULF OF TEHUANTEPEC GALE WARNING...THE PRESENT SYNOPTIC SET-UP
ACROSS THE REGION...WITH HIGH PRESSURE RIDGING SOUTHWARD ACROSS
EASTERN MEXICO AND HIGH AMPLITUDE TROUGHING ACROSS THE CENTRAL
CARIBBEAN SEA AND ADJACENT W ATLANTIC IS PROVIDING A VERY
FAVORABLE ENVIRONMENT FOR THE ONGOING GAP WIND EVENT ACROSS THE
NE TROPICAL PACIFIC. GALE FORCE NORTHERLY WINDS CONTINUE TO
FUNNEL THROUGH THE GULF OF TEHUANTEPEC AND DOWNSTREAM THIS
MORNING WITH THE LATEST ASCAT PASS INDICATING WINDS UP TO 40 KT.
THESE WINDS ARE EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS BEFORE DIMINISHING BELOW GALE FORCE. PEAK SEAS ARE FROM 13
TO 15 FT. WEAKENING OF THE PRESSURE GRADIENT TODAY...WILL LEAD
TO NOCTURNAL WINDS OF ONLY 30 KT OVER A MUCH SMALLER AREA BOTH
MONDAY AND TUESDAY NIGHTS.

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

A MONSOONAL CIRCULATION IS NOT CURRENTLY EVIDENT ACROSS THE FAR
TROPICAL NE PACIFIC. THE ITCZ EXTENDS FROM 04N88W TO 06N110W TO
09N120W TO 06N137W TO BEYOND 04N140W. SCATTERED MODERATE TO
STRONG CONVECTION IS FROM 03N TO 14N W OF 124W.

...DISCUSSION... 

STRONG HIGH PRESSURE OVER THE WESTERN U.S. COMBINED WITH
TROUGHING ACROSS WESTERN MEXICO AND THE SIERRA MADRE INDUCE A
SURGE OF NW TO N WINDS OF 20-25 KT DOWN GREAT PORTIONS OF THE
GULF OF CALIFORNIA. THESE WINDS MAY INCREASE TO 30 KT THIS
MORNING ACROSS CENTRAL PORTIONS OF THE GULF...WITH SEAS BUILDING
8 TO 9 FT. THE WINDS AND SEAS THEN WILL SLIGHTLY DIMINISH
THROUGH WED.
                                       
A COLD FRONT IS OVER NW PORTIONS OF THE FORECAST WATERS FROM
30N136W TO 29N140W...WHILE A BROAD RIDGE IS WSW OF THE FRONT
ANCHORED BY A 1024 MB HIGH W OF 140W. THE PRESSURE GRADIENT
BETWEEN THE RIDGE AND OLD FRONTAL REMNANTS ALONG 03-13N W OF
122W IS SUPPORTING AN ELONGATED AREA OF 20-25 KT NE WINDS
OCCURRING FROM 08N TO 18N W OF 117W. THIS IS RESULTING IN A
LARGE AREA OF 10-12 FT SEAS THERE. THIS AREA OF STRONG NE TRADES
IS EXPECTED TO SHIFT WSW AS RIDGING BUILDS SOUTHEASTWARD ACROSS
THE NORTHERN FORECAST WATERS THROUGH TUESDAY. LARGE NW SWELL
GENERATED BEHIND THE COLD FRONT WILL GRADUALLY SUBSIDE TO 10-11
FT THIS EVENING.

GAP WINDS... 

AS MENTIONED ABOVE...THE SYNOPTIC PRESSURE PATTERN CONDUCIVE FOR
THE ONGOING GULF OF TEHUANTEPEC GALE EVENT IS ALSO VERY
FAVORABLE FOR STRONG NE WINDS TO FUNNEL THROUGH THE GULF OF
PAPAGAYO...THE GULF OF FONSECA...AND MOST OF THE OTHER GAP WIND
PRONE AREAS OF CENTRAL AMERICA THROUGH MAINLY THIS MORNING WITH
POSSIBLE SMALLER AREAS OF GAP WINDS TO OCCUR LATE AT NIGHT INTO
EARLY TUE MORNING. SEAS ASSOCIATED WITH THESE WINDS ARE FORECAST
TO BE IN THE 8-9 FT RANGE...BUT SUBSIDE TO LESS THAN 8 FT EARLY
ON TUE. FRESH TO BRIEFLY STRONG N WINDS WILL SURGE THROUGH THE
GULF OF PANAMA AND EXTEND SOUTHWARD THROUGH THIS MORNING...THEN
DIMINISH TO 15-20 KT EARLY IN THE AFTERNOON BEFORE INCREASING TO
AROUND 20 KT AGAIN LATE MON NIGHT...WITH RESULTANT SEAS OF 5-7
FT.
 
$$
NR