000
AXPZ20 KNHC 222156
TWDEP 

TROPICAL WEATHER DISCUSSION                              
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC THU JAN 22 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 
2100 UTC. 

...SPECIAL FEATURES...                                          
A GALE WARNING IS ALREADY IN EFFECT FOR THE GULF OF TEHUANTEPEC. 
MARINE GUIDANCE SUGGESTS ONSET OF THE EVENT BEGINNING AROUND 
24/0300 UTC WITH NORTHERLY WINDS QUICKLY REACHING MINIMAL GALE 
FORCE BY 24/0600 UTC. WINDS WILL FURTHER INCREASE TO 40 KT BY 
24/1200 UTC. THIS GAP WIND EVENT WILL BE ASSOCIATED WITH A SURGE 
OF COLD AIR BEHIND A COLD FRONT FORECAST TO MOVE ACROSS THE 
WESTERN GULF OF MEXICO FRI...AND THROUGH THE ENTIRE GULF SAT. 
EXPECT MAX SEAS TO 15-16 FT BY LATE SAT WITH THE STRONGEST 
WINDS. MINIMAL GALE FORCE WINDS ARE EXPECTED TO PERSIST THROUGH 
MON MORNING.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 07N77W TO 09N86W TO 07N95W. THE 
ITCZ CONTINUES FROM 07N95W TO 06N110W TO 05N130W TO 06N140W. 
SCATTERED MODERATE CONVECTION IS NOTED FROM 05N TO 08N BETWEEN 
78W AND 80W...AND FROM 2.5N TO 06N BETWEEN 81W AND 83W. ISOLATED 
MODERATE CONVECTION IS FROM 05N TO 07N BETWEEN 117W AND 120W.

...DISCUSSION...                                                
ALOFT...A WELL ORGANIZED UPPER LEVEL LOW IS CENTERED NEAR 
18N128W. THIS SYSTEM IS PRODUCING SCATTERED SHOWERS AND ISOLATED 
TSTMS...PARTICULARLY FROM 15N TO 18N BETWEEN 121W AND 125W. A 
WEAK SURFACE TROUGH...REFLECTION OF THE LOW IS ANALYZED FROM 
FROM 20N128W TO 16N128W. THIS SYSTEM IS FORECAST TO REMAIN 
NEARLY STATIONARY OVER THE 24-36 HOURS THEN WILL DISSIPATE.

SURFACE HIGH PRES OF 1028 MB LOCATED N OF AREA NEAR 36N129W 
EXTENDS A RIDGE SE ACROSS THE N WATERS TO NEAR 18N108W. MODERATE 
TO LOCALLY FRESH WINDS ARE NOTED PER SCATTEROMETER DATA ACROSS 
THE SOUTHERN PERIPHERY OF THE RIDGE...MAINLY FROM 18N TO 24N W 
OF 120W. PRES GRADIENT BETWEEN THE RIDGE AND THE AFOREMENTIONED 
SURFACE TROUGH ALSO SUPPORTS THESE WINDS. THIS HIGH PRES WILL 
REMAIN NEARLY STATIONARY DURING THE NEXT 24 HOURS.

LARGE LONG PERIOD NW SWELLS ARE ALREADY IMPACTING THE NW WATERS 
WITH BUILDING SEAS OF 12-13 FT NEAR 30N140W. BY FRI MORNING... 
THE NW SWELL WILL CONTINUE TO PUSH INTO THE FORECAST WATERS WITH 
SEAS OF 12-13 FT AFFECTING THE AREA N OF 16N W OF 132W. THE COLD 
FRONT ASSOCIATED WITH THIS SWELL EVENT IS NOT EXPECTED TO REACH 
THE AREA UNTIL LATE SUN.

HIGH PRES BUILDING OVER THE SOUTHWEST U.S. WILL COMBINE WITH A 
SURFACE TROUGH ACROSS NW MEXICO TO TIGHTEN THE PRESSURE GRADIENT 
IN THE NORTHERN GULF OF CALIFORNIA. WINDS ARE FRESH TO STRONG N 
OF 25N THIS AFTERNOON. STRONGEST WINDS WILL SPREAD SOUTHWARD TO 
ENCOMPASS MOST OF THE GULF OF CALIFORNIA THROUGH FRI...WITH 
FRESH NW WINDS EXPECTED TO PERSIST IN THE REGION THROUGH SAT.

GAP WINDS...                                               
PULSING OF NOCTURNAL WINDS ARE EXPECTED ACROSS THE GULF OF 
PAPAGAYO REACHING 20 KT FROM 0600 TO 1200 UTC WITH SEAS OF 
AROUND 6 FT THROUGH AND DOWNWIND OF THE GULF OVERNIGHT TONIGHT. 
WINDS WILL INCREASE AGAIN TO 20-25 KT SAT NIGHT INTO SUN MORNING 
AS HIGH PRES BUILDS ACROSS THE NW CARIBBEAN.

FRESH N WINDS WILL PERSIST IN THE GULF OF PANAMA DURING THE 
OVERNIGHT AND EARLY MORNING HOURS THROUGH FRI MORNING DUE TO THE 
PRESENCE OF FRESH TO STRONG WINDS ACROSS THE SW CARIBBEAN. MAX 
SEAS OF 6 FT ARE EXPECTED AT PEAK WINDS DURING THE MORNING HOURS.

$$ 
GR