000
AXPZ20 KNHC 172202
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC SAT JAN 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC. 

...SPECIAL FEATURES...                                       

GULF OF TEHUANTEPEC GALE WARNING...THE HIGH PRESSURE RIDGE 
EXTENDING ACROSS THE WESTERN GULF OF MEXICO AND ALONG MEXICO'S 
EAST COAST HAS WEAKENED...WITH WINDS THERE DIMINISHING 
CONSIDERABLY DURING THE PAST 24 HOURS. STRONG NORTHERLY WIND 
FORCING HAS THEREFORE ENDED THROUGH THE ISTHMUS OF TEHUANTEPEC 
AND GALES ENDED THIS MORNING ACROSS AND DOWNSTREAM OF THE GULF 
OF TEHUANTEPEC. WINDS THERE ARE CURRENTLY ESTIMATED AT 20-30 KT 
N OF 14.5N...AND WILL DIMINISH FURTHER IN AREAL EXTENT TONIGHT.  
HIGH PRES BUILDING INTO SOUTHERN TEXAS AND NE MEXICO SUNDAY WILL 
TIGHTEN THE PRESSURE GRADIENT ONCE AGAIN...WITH WINDS EXPECTED TO 
REACH MINIMAL GALE AROUND 1500-1800 UTC SUN. PEAK WINDS ARE 
EXPECTED TO BE 35 TO 40 KT SUN NIGHT...AND REMAIN AT GALE FORCE 
THROUGH MON MORNING.

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

THE MONSOON TROUGH FROM 06N75W TO 03N80W TO 06N87W...THEN ITCZ 
TO 05.5N102W TO 10N118W...WHERE IT BREAKS...THEN RESUMES FROM 
07N123W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION NOTED WITHIN 60 NM OF AXIS E OF 87W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 150 NM N AND 
120 NM S OF AXIS E OF 88W. SCATTERED TO LOCALLY NUMEROUS 
MODERATE TO STRONG CONVECTION NOTED FROM 09N TO 15.5N BETWEEN 
111W AND 121W.

...DISCUSSION...                                                 

A 1012 MB LOW IS CENTERED NEAR 19.5N120.5W MOVING WESTWARD 
AROUND 10 KT. THUNDERSTORM ACTIVITY ASSOCIATED WITH THIS LOW WAS 
NON EXISTENT IN THE PAST COUPLE OF HOURS...AND THE LOW CONTINUES 
TO SLOWLY WEAKEN. STRONG WINDS TO 25 KT WERE OCCURRING WITHIN 
240 NM NE AND 180 NM NW QUADRANTS OF THE LOW...WHERE SEAS WERE 8 
TO 11 FT...WHILE A BROADER AREA OF FRESH NE TRADEWINDS REMAINED 
DRAPED ACROSS N AND NW PORTIONS OF THE LOW FROM 15N TO 24N 
BETWEEN 117W AND 127W. THE LOW IS EXPECTED TO CONTINUE MOVING W 
TO W-NW THROUGH MON AND GRADUALLY WEAKEN...THEN DISSIPATE INTO A 
SURFACE TROUGH AS IT DRIFTS WESTWARD. AN AREA OF ENHANCED SEAS 
TO 9-10 FT WILL ACCOMPANY THE LOW AS IT TRACKS ACROSS WATERS W 
OF 120W. THESE SEAS WILL EVENTUALLY MERGE WITH LARGE AREA OF 
LONG PERIOD NW SWELL ACROSS NW CORNER OF DISCUSSION AREA.

THE SUBTROPICAL RIDGE EXTENDS SOUTHWARD FROM A 1026 MB HIGH NEAR 
32N128W SE TO 25N110W AND SW FROM THE HIGH TO 22N152W. THE PRES 
GRADIENT BETWEEN THE LOW CENTER MENTIONED ABOVE AND THE RIDGE IS 
PRODUCING A BROAD ZONE OF FRESH TRADE WINDS S OF 24N W OF 120W. 
ASSOCIATED WIND WAVES MERGING WITH FADING NW SWELL IS PRODUCING 
SEAS OF 8-10 FT ACROSS THIS AREA. TRADE WIND WAVES WILL DECAY 
SLIGHTLY AND PERSIST MAINLY W OF 125W SUN AND MON.

GULF OF PAPAGAYO...STRONG RIDGING ACROSS CENTRAL AMERICA IS 
SUPPORTING FRESH TO STRONG NE WINDS PULSING THROUGH PAPAGAYO. 
PEAK WINDS WILL CONTINUE TO PULSE IN EXCESS OF 25 KT DURING LATE 
NIGHT AND EARLY MORNING HOURS THROUGH MON...BRIEFLY REACHING 30 
KT DURING MAXIMUM NOCTURNAL DRAINAGE FLOW BEFORE SUNRISE...WITH 
A LULL EACH DAY DURING THE AFTERNOON WITH WINDS LESS THAN 20 KT. 
SEAS WILL REACH 8-9 FT DOWNWIND OF THE GULF EACH MORNING.

GULF OF PANAMA...FRESH TO LOCALLY STRONG N WINDS WILL PERSIST IN 
THE GULF OF PANAMA DUE TO THE PRESSURE GRADIENT ACROSS THE AREA. 
MAX SEAS TO 7 FT EXPECTED AT PEAK WINDS DURING THE EARLY MORNING.
 
$$ 
STRIPLING