000
AXPZ20 KNHC 151503
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU NOV 15 2012

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS FROM 05N78W TO 06N100W THEN ITCZ TO 
10N125W TO 08N130W TO 10N136W TO BEYOND 09N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 120 NM N OF 
AXIS E OF 80W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 
120 NM N OF AXIS BETWEEN 81W AND 103W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 120 NM OF AXIS W OF 
135W.

...DISCUSSION...
HIGH PRESSURE 1018 MB IS CENTERED NEAR 24N120W. LOW PRESSURE 
1001 MB IS CENTERED N OF THE AREA NEAR 32N135W WITH ASSOCIATED 
COLD FRONT ENTERING THE AREA NEAR 30N129W EXTENDING TO BEYOND 
22N140W. THE PRESSURE GRADIENT BETWEEN THE FEATURES IS 
MAINTAINING FRESH TO STRONG WINDS N OF 27N WITHIN 120 NM E OF 
THE FRONT. THE COLD FRONT WILL DISSIPATE OVER THE NEXT 24 HOURS 
AS A SECOND WEAK COLD FRONT WILL PUSH INTO THE AREA. NW SWELL 
ASSOCIATED WITH THE LOW PRESSURE SYSTEM IS PUSHING ACROSS THE NW 
PART OF THE AREA WITH COMBINED SEAS TO 12 FT. THIS SWELL WILL 
SLOWLY SUBSIDE WHILE SPREADING S AND E OVER THE NEXT COUPLE OF 
DAYS.  

GAP WINDS...
GALE FORCE WINDS CONTINUE ACROSS THE GULF OF TEHUANTEPEC THIS 
MORNING...REACHING NEAR 40 KT WITH THE AID OF NOCTURNAL DRAINAGE 
FLOW. WINDS WILL DIMINISH TO JUST BELOW GALE FORCE DURING THE 
AFTERNOON HOURS TODAY AND FRIDAY. HOWEVER...DURING THE OVERNIGHT 
HOURS...THE ADDED COMPONENT OF NOCTURNAL DRAINAGE FLOW WILL PUSH 
WINDS BACK ABOVE GALE FORCE IN THE GULF OF TEHUANTEPEC. 
THUS...HAVE EXTENDED THE GALE WARNING OVER THE GULF OF 
TEHUANTEPEC THROUGH THE FORECAST PERIOD TO ACCOUNT FOR THIS 
PULSING OF WINDS TO GALE FORCE. 

FRESH TO STRONG WINDS OVER THE SW CARIBBEAN FUNNELING THROUGH 
THE GAP IN TOPOGRAPHY OVER NICARAGUA ARE PRODUCING FRESH TO 
STRONG WINDS OVER THE GULF OF PAPAGAYO. THESE WINDS WILL 
CONTINUE THROUGH THE FORECAST PERIOD...PEAKING DURING THE 
OVERNIGHT AND EARLY MORNING HOURS WITH THE ADDED COMPONENT OF 
NOCTURNAL DRAINAGE FLOW. 

$$
AL