000
AXPZ20 KNHC 171457
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT NOV 17 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...
MONSOON TROUGH FROM 08.5N84W TO 05.5N93W WHERE IT TRANSITIONS TO 
ITCZ...CONTINUING TO 08N127W TO BEYOND 07N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 150 NM N OF 
AXIS BETWEEN 125W AND 130W.

...DISCUSSION...
A DISSIPATING COLD FRONT ENTERS THE FORECAST AREA NEAR 30N123W 
AND EXTENDS S AND W TO 24N131W. THE HIGH PRESSURE CENTER THAT 
HAD BEEN E OF THE FRONT THE PAST COUPLE OF DAYS HAS DISSIPATED. 
THIS HAS LOOSENED THE PRESSURE GRADIENT E OF THE FRONT AND WINDS 
REMAIN BELOW 20 KT. THE COLD FRONT WILL WEAKEN TODAY AND 
DISSIPATE BY SUN. A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE 
N PART OF THE AREA TODAY IN THE WAKE OF THE FRONT. THIS WILL 
TIGHTEN THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE ITCZ 
WHICH WILL ONCE AGAIN FRESHEN TRADEWIND FLOW...ESPECIALLY 
BETWEEN 10N AND 20N W OF 130W...BY TONIGHT. 

LONG PERIOD NW SWELL CONTINUES TO PUSH ACROSS THE NW PART OF THE 
REGION WITH COMBINED SEAS TO 9 FT. THIS SET OF NW SWELLS WILL 
CONTINUE TO PROPAGATE S AND E ACROSS THE REGIONAL WATERS OVER 
THE NEXT DAY WITH SEAS CONTINUING TO SLOWLY SUBSIDE. ADDITIONAL 
PULSES OF NW SWELLS WILL ENTER THE NW PART OF THE AREA BY EARLY 
SUN...WITH SEA HEIGHTS REACHING 12 FT OVER THE FAR NW PART OF 
THE AREA. 

GAP WINDS...
A GALE WARNING REMAINS IN EFFECT ACROSS THE GULF OF TEHUANTEPEC. 
WINDS WILL DIMINISH TO JUST BELOW GALE FORCE DURING THE 
AFTERNOON HOURS TODAY AND SUNDAY. HOWEVER...MINIMAL GALE FORCE 
WINDS WILL CONTINUE TO PULSE ACROSS THE GULF OF TEHUANTEPEC 
DURING THE OVERNIGHT AND EARLY MORNING HOURS...ESPECIALLY DURING 
THE 0600 TO 1200 UTC TIME FRAME...WITH THE ASSISTANCE OF THE 
NOCTURNAL DRAINAGE FLOW. THIS GAP WIND EVENT IS FORECAST TO 
PERSIST THROUGH AT LEAST MON MORNING. 

PULSING OF NOCTURNAL WINDS ARE ALSO EXPECTED ACROSS THE GULF OF 
PAPAGAYO REACHING AROUND 20 KT FROM 0600 TO 1200 UTC...WITH SEAS 
OF 6-7 FT THROUGH AND DOWNWIND OF THE GULF.  

$$
AL