000
AXPZ20 KNHC 221536
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU NOV 22 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 IS ALONG 08N78W TO 07N96W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 07N96W TO 08N115W TO 09N130W 
TO 09N140W. SCATTERED MODERATE WITHIN 120 NM EITHER SIDE OF THE 
TROUGH E OF 87W...AND WITHIN 60 NM EITHER SIDE OF THE TROUGH 
BETWEEN 88W AND 92W. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION IS WITHIN AN AREA BOUNDED BY 11N131W TO 11N123W TO 
05N121W TO 07N131W TO 11N131W. SCATTERED MODERATE WITHIN 60 NM 
EITHER SIDE OF ITCZ BETWEEN 133W AND 136W.

...DISCUSSION...

GULF OF TEHUANTEPEC...OVERNIGHT OBSERVATIONS INDICATED THAT THE 
GALE FORCE WIND EVENT MAY HAVE CONTINUED THROUGH 06Z...ALTHOUGH 
FORCING FOR THIS EVENT HAS LIKELY DIMINISHED TO NEAR GALE EARLY 
THIS MORNING AS HIGH PRES OVER FAR EASTERN MEXICO AND THE 
WESTERN GULF OF MEXICO HAS SHIFTED E ENOUGH TO ALLOW FOR THE 
GRADIENT TO RELAX BELOW GALE FORCE. THE REPRIEVE WILL BE SHORT 
LIVED HOWEVER...SINCE THE NEXT SURGE OF COOLER AND DRIER AIR 
WILL PUSH ACROSS THE WESTERN GULF OF MEXICO THROUGH THE CHIVELA 
PASS AND INTO THE GULF OF TEHUANTEPEC BY LATE FRI NIGHT INTO 
EARLY MORNING...INDUCING ANOTHER GALE EVENT COMMENCING AROUND 06 
UTC SAT.

GULF OF PAPAGAYO...ANOTHER GAP WIND EVENT IN THE GULF OF 
PAPAGAYO CONTINUES TO PRODUCE STRONG BREEZE CONDITIONS. THIS 
EVENT SHOULD CONTINUE FOR THE NEXT COUPLE OF DAYS WITH LITTLE 
CHANGE...BUT WITH THE TYPICAL DIURNAL VARIABILITY WITH WEAKER 
WINDS AND LOWER SEAS DURING THE AFTERNOON AND EARLY EVENING.

A BROAD AREA OF CONVECTION IS NOTED ON SATELLITE IMAGERY AROUND 
PANAMA AND ALONG THE MONSOON TROUGH E OF 92W. OVERNIGHT 
SCATTEROMETER DATA SHOWED MODERATE TO FRESH CROSS-EQUATORIAL SW 
FLOW INTO THIS AREA CONVERGING WITH MODERATE TO FRESH N TO NE 
FLOW OVER THE SW CARIBBEAN SEA. GOES SATELLITE DERIVED WINDS AND 
WATER VAPOR IMAGERY SHOW WEAK UPPER LEVEL TROUGHING JUST WEST OF 
THE CONVECTIVE AREA...LIKELY PROVIDING ADDITIONAL UPPER 
DIVERGENCE AND LIFT. GLOBAL MODELS CONTINUE TO SHOW THE 
DEVELOPMENT OF WEAK LOW PRES ALONG THE MONSOON TROUGH NEAR 
08N97W MOVING W THROUGH FRI...INTERACTING WITH THE PAPAGAYO 
PULSES TO THE N TO ENHANCE EASTERLY FLOW. SLIGHTLY ELEVATED 
WINDS AND SEAS WILL BE ACROSS THE AREA FROM 05N TO 09N E OF 87W.

FURTHER WEST...OVERNIGHT ASCAT SCATTEROMETER PASSES CONFIRMED A 
MODEL DIAGNOSED AREA OF FRESH TO STRONG TRADE WINDS FROM 14N TO 
19N W OF 125W. 1024 MB HIGH PRES IS STRADDLING THE FAR N CENTRAL 
DISCUSSION WATERS NEAR 30N130W WITH A RIDGE EXTENDING TO A SE 
TERMINUS NEAR 20N112W. THE PRES GRADIENT S OF THE RIDGE AND N OF 
THE ITCZ WILL CONTINUE TO SUPPORT THESE WINDS ACROSS THE SAME 
GENERAL AREA THROUGH SAT.

LONG-PERIOD...13-15 SECOND NW SWELL WITH SIGNIFICANT WAVE 
HEIGHTS OF UP TO 12 FEET ARE OCCURRING IN THE NW PORTION OF THE 
AREA AS MEASURED BY AN OVERNIGHT ALTIMETER PASS GENERATED BY A 
WINTER STORM IN THE GULF OF ALASKA. THIS SET OF NW SWELL WILL 
CONTINUE TO PROPAGATE TO THE SE...GRADUALLY DECAYING DURING THE 
NEXT FEW DAYS. THE NEXT NOTEWORTHY LONG-PERIOD SWELL EVENT MAY 
OCCUR BEGINNING NEXT WEDNESDAY.

$$
LEWITSKY