000
AXPZ20 KNHC 152127
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 05N78W TO 06N100W THEN THE ITCZ AXIS 
CONTINUES TO 10N125W TO 08N130W TO 10N135W TO BEYOND 09N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF TROUGH 
BETWEEN 79W AND 84W. SIMILAR CONVECTION IS ALSO NOTED WITHIN 90 
NM N OF AXIS BETWEEN 102W AND 114W...WITHIN 45 NM EITHER SIDE OF 
AXIS BETWEEN 118W AND 120W...AND FROM 07N TO 10N W OF 135W.

...DISCUSSION...
HIGH PRESSURE 1020 MB IS CENTERED NEAR 25N121W. LOW PRESSURE 
1004 MB IS CENTERED N OF THE AREA NEAR 32N133W WITH ASSOCIATED 
COLD FRONT ENTERING THE FORECAST REGION NEAR 30N126W EXTENDING 
TO 20N134W. THE COLD FRONT WILL DISSIPATE OVER THE NEXT 24 HOURS 
AS A SECONDARY COLD FRONT MOVES INTO THE AREA. NW SWELL 
ASSOCIATED WITH THE LOW PRESSURE SYSTEM IS PUSHING ACROSS THE NW 
PART OF THE REGION WITH COMBINED SEAS TO 13 FT. THIS SWELL EVENT 
WILL SLOWLY SUBSIDE WHILE SPREADING S AND E OVER THE NEXT COUPLE 
OF DAYS. 

A COUPLE OF WEAK TROUGHS ARE EMBEDDED IN THE ITCZ. ONE IS ALONG 
118W FROM 07N TO 11N AND THE OTHER ALONG 127W FROM 08N TO 14N. A 
CLUSTER OF MODERATE TO STRONG CONVECTION IS NEAR THE NORTHERN 
END OF THE WESTERNMOST TROUGH. 

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. SO...THE 
GALE WARNING HAS EXTENDED 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. 

NLY WINDS OF 20 KT ARE ALSO NOTED BY SCATTEROMETER DATA THROUGH 
THE GULF OF PANAMA AND DOWNSTREAM TO NEAR 06N. THIS WILL BE A 
SHORT-LIVED EVENT. 

$$
GR