000
AXPZ20 KNHC 132137
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE NOV 13 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 06N77W TO 06N96W TO 07N110W THEN 
TRANSITIONS TO ITCZ TO LOW PRES NEAR 10N116N 1009 MB TO LOW PRES 
NEAR 09N131W 1009 MB TO BEYOND 09N140W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 90 NM N OF THE ITCZ 
AXIS BETWEEN 120W AND 124W. SIMILAR CONVECTION IS FROM 06N TO 
10N BETWEEN 132W AND 138W. 

...DISCUSSION...
BROAD UPPER LEVEL RIDGE ANCHORED ON AN UPPER ANTICYCLONE 
CENTERED NEAR 16N113W DOMINATES MOST OF BASIN BETWEEN 96W AND 
133W. BROAD UPPER LEVEL EQUATORIAL CYCLONE DIRECTLY TO THE S OF 
ANTICYCLONE IS NOW LOCATED NEAR 02N113W. DEEP LAYERED ELY FLOW 
BETWEEN THESE TWO FEATURES IS HELPING TO ACCELERATE MOTION OF 
LOW PRES CENTERS EMBEDDED IN THE ITCZ DESCRIBED ABOVE. LONG WAVE 
TROUGH CROSSES NEAR 30N141W THEN CONTINUES SW TO JUST E OF THE  
HAWAIIAN ISLANDS. STRONG SWLY FLOW OF 70-90 KT IS NOTED AHEAD OF 
THE TROUGH AXIS AFFECTING THE NW CORNER OF THE FORECAST AREA. 
THIS LONG WAVE TROUGH SUPPORTS A COLD FRONT APPROACHING NW 
PORTIONS THIS AFTERNOON WITH A SECONDARY AND STRONGER COLD FRONT 
FARTHER NW REACHING 35N145W. THESE FRONTS ARE EXPECTED TO MERGE 
AND MOVE SLOWLY SE INTO NW PORTIONS TONIGHT INTO WED...WITH SWLY 
WINDS OF 20 TO 25 KT DEVELOPING E OF FRONT...AND NW SWELL 
SPREADING INTO AREA. 

...ELSEWHERE AT THE LOWER LEVELS...
WEAKENING 1024 MB HIGH PRES SITUATED NEAR 32N128W HAS A WEAK 
RIDGE EXTENDING SE TO NEAR 21N110W. PRES GRADIENT BETWEEN THIS 
HIGH AND SEMI-PERMANENT TROUGH ALONG DESERT W COAST OF MEXICO 
HAS ALSO WEAKENED...WITH WINDS OF 20 KT ACROSS THE GULF OF 
CALIFORNIA. 

GAP WINDS...
GULF OF TEHUANTEPEC...STRONG NORTHERLY WINDS CONTINUE TO BLOW 
ACROSS THE CHIVELA PASS INTO GULF OF TEHUANTEPEC. LATEST 
SCATTEROMETER DATA INDICATED GALE FORCE WINDS OF 35 KT ACROSS 
THE AREA. GALES ARE EXPECTED TO PERSIST THROUGH THU MORNING 
BEFORE WINDS DIMINISH TO 20-30 KT INTO THE WEEKEND.

GULF OF PAPAGAYO...COLD FRONT ENTERING THE WESTERN ATLC IS 
EXPECTED TO FORCE THE ATLC RIDGE FURTHER E EASING WESTERN 
CARIBBEAN PRES GRADIENT WHICH IN TURN DIMINISHES STRONG BREEZE 
ACROSS NICARAGUA GAPS INTO GULF OF PAPAGAYO. STRONG NE-E BREEZE 
WILL STILL CONTINUE...BUT FRESH NE GAP WIND FLOW IS EXPECTED TO 
BEGIN TO PULSE TO NEAR 25 KT ONLY DURING THE NIGHT TIME HOURS BY 
WED WHILE SEAS GRADUALLY DIMINISH TO 6-7 FT.

$$
GR/SS