000
AXPZ20 KNHC 131605
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 06N76W TO 09N84W TO 06.5N99W TO LOW PRES 
NEAR 09.5N114.5W 1009 MB THEN TRANSITIONS TO ITCZ TO LOW PRES 
NEAR 09N129N 1009 MB TO BEYOND 09N134W. ISOLATED TO SCATTERED 
MODERATE CONVECTION NOTED WITHIN 90 NM OF TROUGH AXIS E OF 90W.  
SCATTERED MODERATE TO STRONG WITHIN 180 NM NE SEMICIRCLE AND W 
QUADRANT OF LOW PRES NEAR 09.5N114.5W 1009 MB. SCATTERED 
MODERATE TO STRONG WITHIN 150 NM N SEMICIRCLE LOW PRES NEAR 
09N129N 1009 MB. 

...DISCUSSION...
BROAD WELL ANCHORED UPPER LEVEL RIDGE CENTERED ON UPPER 
ANTICYCLONE REORGANIZING SLIGHTLY NE NEAR 15N115W...AND 
DOMINATES MOST OF BASIN BETWEEN 96W AND 133W. BROAD UPPER LEVEL 
EQUATORIAL CYCLONE DIRECTLY TO THE S OF ANTICYCLONE SHIFTING W 
AND NOW CENTERED NEAR 02N116W. DEEP LAYERED ELY FLOW BETWEEN 
THESE TWO FEATURES HELPING TO ACCELERATE MOTION OF LOW PRES 
CENTERS ALONG ITCZ DESCRIBED ABOVE.  LONG WAVE TROUGH ACROSS FAR 
NE PACIFIC EXTENDS SW TO NEAR 31N144W AND MERGING WITH 
ELONGATING CYCLONIC VORTEX NE OF THE HAWAIIAN ISLANDS...WHICH 
HAS BEEN DIGGING SSE OVERNIGHT. MERGED TROUGHS WILL GRADUALLY 
SHIFT E NEXT 48 HOURS AND FORCE UPPER RIDGE TO RECENTER FARTHER 
E AND AMPLIFY ALONG 112W. 

LONG WAVE TROUGH SUPPORTING COLD FRONT APPROACHING NW PORTIONS 
THIS MORNING WITH SECONDARY AND STRONGER FRONT FARTHER NW 
APPROACHING 33N135W. FRONT EXPECTED TO MERGE AND MOVE SLOWLY SE 
INTO NW PORTIONS BETWEEN 24 AND 48 HOURS...WITH SWLY WINDS TO 25 
KT DEVELOPING E OF FRONT...AND NW SWELL INTRUDING INTO AREA. 

...ELSEWHERE AT THE LOWER LEVELS...
WEAKENING 1024 MB HIGH NEAR 32N128W WITH WEAK RIDGE SE TO NEAR 
21N110W. PRES GRADIENT BETWEEN WEAKENED HIGH AND SEMIPERMANENT 
TROUGH ALONG DESERT W COAST OF MEXICO HAS ALSO WEAKENED...WITH 
PARTIAL OVERNIGHT SCATTEROMETER PASSES SUGGESTING WINDS 
GRADUALLY WEAKENING WITHIN THE GULF OF CALIFORNIA...AND EXPECTED 
TO DROP BELOW 20 KT THIS AFTERNOON. 

GULF OF TEHUANTEPEC...STRONG NORTHERLY WINDS CONTINUE THROUGH 
ISTHMUS OF TEHUANTEPEC...AND HAVE PEAKED NEAR 40 KT EARLY THIS 
MORNING...WITH DOWNWIND SEAS TO 15 FT. GALES EXPECTED TO PERSIST 
THROUGH THU MORNING BEFORE WINDS DIMINISH TO 20-30 KT INTO THE 
WEEKEND.

GULF OF PAPAGAYO...COLD FRONT ENTERING WESTERN ATLC EXPECTED TO 
FORCE 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.

$$
STRIPLING