000
AXPZ20 KNHC 090340
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC FRI JAN 09 2015

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC. 

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...STRONG HIGH PRES OVER THE SE 
CONUS EXTENDS A RIDGE SOUTHWESTWARD TOWARD EASTERN TEXAS...THEN 
SOUTHWARD ALONG THE MEXICO COASTAL PLAINS TO SE MEXICO. THIS 
WEATHER PATTERN CONTINUES TO MAINTAIN A TIGHT PRES GRADIENT 
ACROSS THE ISTHMUS OF TEHUANTEPEC SUPPORTING GALE FORCE WINDS OF 
30-40 KT THROUGH THE GULF OF TEHUANTEPEC. THE MOST RECENT 
SCATTEROMETER PASS CONFIRMED THE PRESENCE OF THESE WINDS. THE 
NORTHERLY WINDS ARE FORECAST TO DIMINISH TO 25-30 KT ON FRI 
AFTERNOON AND EVENING WITH ANOTHER SURGE OF 30-35 KT IN THE 
MAXIMUM DRAINAGE FLOW FRI NIGHT THROUGH THE EARLY MORNING HOURS 
SAT. NE TO E SWELL ASSOCIATED WITH THIS EVENT COMBINED WITH A 
GALE WIND EVENT OVER THE GULF OF PAPAGAYO IS PRODUCING A VERY 
LARGE AREA OF SEAS 8 FT OR GREATER THAT EXTENDS SW TO BEYOND 
110W. BY FRI...8-11 FT SEAS WILL COVER MUCH OF THE AREA S OF 14N 
BETWEEN 92W AND 120W.

GULF OF PAPAGAYO GALE WARNING...THE STRONG PRESSURE GRADIENT IS 
COMBINING WITH STRONG TRADE WINDS IN THE WESTERN CARIBBEAN TO 
SUPPORT AN UNUSUALLY STRONG GAP WIND EVENT ACROSS THE GULF OF 
PAPAGAYO. MINIMAL GALE FORCE WINDS ARE EXPECTED AGAIN TONIGHT 
THROUGH THE EARLY MORNING HOURS FRI. THEN...WINDS WILL REMAIN 25-
30 KT THROUGH SAT MORNING AS STRONG HIGH PRES PERSISTS N OF 
AREA. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH EXTENDS FROM 05N77W TO 03N80W TO 03N84W. THE 
ITCZ CONTINUES FROM 03N84W TO 05N100W TO 07N120W TO 08N140W. 
SCATTERED MODERATE CONVECTION IS NOTED FROM 06N TO 09N BETWEEN 
113W AND 119W. SIMILAR CONVECTION IS FROM 08N TO 09N BETWEEN 
130W AND 132W.
 
...DISCUSSION...                                                 

A WEAK 1018 MB HIGH PRES LOCATED NEAR 24N124W EXTENDS A RIDGE 
ACROSS THE NE PART OF THE FORECAST AREA. THIS SYSTEM WILL MOVE 
SE OVER THE NEXT 24 HOURS AS A COLD FRONT CONTINUES TO MOVES 
EASTWARD ACROSS THE N WATERS. CURRENTLY...THE FRONT STRETCHES 
FROM 30N128W TO 21N135W...THEN A FRONTAL TROUGH CONTINUES TO 
17N140W. THE PRES GRADIENT BETWEEN THESE FEATURES IS SUPPORTING 
MODERATE TO FRESH SOUTHERLY WINDS AHEAD OF THE FRONT. ALSO...THE 
PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURE ALONG THE 
ITCZ IS MAINTAINING LARGE AREA OF FRESH TO LOCALLY STRONG WINDS 
N OF THE ITCZ W OF 110W. TRADE WIND CONVERGENCE IS PRODUCING 
MODERATE CONVECTION AS MENTIONED ABOVE. THE COLD FRONT WILL 
SHIFT EASTWARD AND GRADUALLY WEAKEN THROUGH SAT. LONG PERIOD NW 
SWELL ASSOCIATED WITH THE FRONT WILL PROPAGATE E-SE WITH MAX 
SEAS TO 12-13 FT AT PRESENT SUBSIDING TO 10-11 FT ON FRI.

HIGH PRES IN THE WAKE OF THE FRONT WILL DOMINATE THE NW PORTION 
OF THE AREA AND BRING AN INCREASE IN THE TRADE WIND FLOW MAINLY 
ACROSS THE WEST-CENTRAL WATERS FRI EVENING INTO SAT. EXPECT NE 
TO E WINDS OF 20-25 KT FROM 08N TO 13N W OF 127W WITH SEAS TO 11 
FT IN MIXED NE AND NW SWELL.

FRESH TO LOCALLY STRONG N WINDS ARE FUNNELING INTO THE GULF OF 
PANAMA FROM THE CARIBBEAN. WINDS WILL PULSE TO 25 KT DURING LATE 
NIGHT AND EARLY MORNING HOURS FOR THE NEXT TWO DAYS AND DIMINISH 
TO 20 KT OR LESS DURING THE AFTERNOON AND EARLY EVENING HOURS. 

LOOKING AHEAD...THE NEXT GALE FORCE GAP WIND EVENT ACROSS THE 
GULF OF TEHUANTEPEC IS EXPECTED MON NIGHT INTO TUE MORNING BASED 
ON MARINE GUIDANCE. 

$$ 
GR