000
AXPZ20 KNHC 220317
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

FROM 08N83W TO 06N95W. ITCZ FROM 06N95W TO 09N125W TO BEYOND 
07N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM N AND 60 NM 
S OF AXIS E OF 92W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 90 NM EITHER SIDE OF THE ITCZ W OF 125W.

...DISCUSSION...

GULF OF TEHUANTEPEC...THE MAIN FORECAST ISSUE CONTINUES TO BE A 
LONG LIVED GALE FORCE EVENT IN THE GULF OF TEHUANTEPEC. A 1630 
UTC ASCAT PASS INDICATED WINDS TO NEAR GALE FORCE ALONG THE 
COAST AND OBSERVATIONS FROM SALINA CRUZ AND IXTEPEC NEAR THE 
SOUTHERN TERMINUS OF THE TEHUANTEPEC ISTHMUS INDICATE SUSTAINED 
WINDS 15 TO 20 KT...WITH GUSTS TO 30 KT AT SALINA CRUZ. HIGH 
PRES IS BUILDING OVER THE NW GULF ALONG WITH CONTRIBUTIONS FROM 
OVERNIGHT DRAINAGE MAY ALLOW WINDS TO REACH GALE FORCE AGAIN 
DURING LATE TONIGHT INTO EARLY THU MORNING. THE HIGH PRES IN THE 
GULF OF MEXICO WILL SHIFT E THROUGH THU...ALLOWING FOR THE 
GRADIENT TO RELAX BELOW GALE FORCE THROUGH THU NIGHT. THE 
REPRIEVE WILL BE SHORT LIVED HOWEVER...SINCE THE NEXT SURGE OF 
COOLER AND DRIER AIR WILL PUSH ACROSS THE WESTERN GULF OF MEXICO 
INTO THE GULF OF TEHUANTEPEC BY LATE FRI NIGHT INTO EARLY 
MORNING...INDUCING ANOTHER GALE EVENT POSSIBLY AS EARLY AS FRI 
NIGHT.

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. 
FORCING FOR THIS EVENT SHOULD SUBSIDE BELOW OUR 25 KT CRITERION 
BY MONDAY.

A BROAD AREA OF CONVECTION IS NOTED ON SATELLITE IMAGERY AROUND 
PANAMA AND ALONG THE MONSOON TROUGH E OF 92W. SCATTEROMETER DATA 
FROM 17 UTC SHOWED MODERATE TO FRESH CROSS-EQUATORIAL SW FLOW 
INTO THIS AREA CONVERGING WITH MODERATE TO FRESH N TO NE FLOW 
OVER THE SW CARIBBEAN. GOES 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 A 
WEAK LOW PRES AREA ALONG THE MONSOON TROUGH NEAR 08N97W AROUND 
COCOS ISLAND THROUGH FRI...INTERACTING WITH THE PAPAGAYO PULSES 
TO THE NORTH TO ENHANCE EASTERLY FLOW. ASIDE FROM THE SLIGHTLY 
ELEVATED WINDS AND SEAS...THE MAIN IMPACT WILL BE AREAS FROM 05N 
TO 10N E OF 87W. 

FARTHER WEST...A 18 UTC ASCAT PASS CONFIRMED AN AREA OF 20 TO 25 
KT TRADE WINDS FROM 12N TO 19N BETWEEN 125W AND 135W...SOUTH OF 
A 1024 MB CENTERED NEAR 28N129W. THESE WINDS WILL DIMINISH AS 
THE HIGH PRES WEAKENS AND DRIFTS N. 

LONG-PERIOD...13-15 SECOND...NW SWELL WITH SIGNIFICANT WAVE 
HEIGHTS OF UP TO 12 FEET ARE OCCURRING IN OUR NW AREA OF 
RESPONSIBILITY DUE TO FORCING FROM A WINTER STORM SOUTH OF 
ALASKA.  THIS NW SWELL WILL BE PUSHING SOUTHEASTWARD AND 
GRADUALLY DIMINISHING OVER THE NEXT COUPLE OF DAYS. THE NEXT 
NOTEWORTHY LONG-PERIOD SWELL EVENT MAY OCCUR BEGINNING NEXT 
WEDNESDAY.

$$
CHRISTENSEN