000
AXPZ20 KNHC 130953
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 06N78W TO 09N84W TO 07N96W TO 08N107W THEN ITCZ TO 
10N112W TO 07N118W TO 1009 MB LOW PRES AT 10N128W TO 09N130W TO 
10N136W.  ISOLATED MODERATE WITHIN 75 NM S OF AXIS E OF 94W. 

...DISCUSSION...
BROAD WELL ANCHORED UPPER LEVEL RIDGE CENTERED AT 15N122W 
DOMINATES MOST OF BASIN AND BLOCKS AND FURTHER INTRUSION OF WEAK 
SHORTWAVE INTO NW CORNER OF E PAC.  RIDGE ADVECTS LARGE AMOUNT 
OF MOISTURE ON WEAKENING 70 KT SW JET CORE HEADING INTO MEXICO N 
OF 20N.  ON THE OTHER HAND...RIDGE MAINTAINS DRY AIR MASS ON ITS 
SE SEMICIRCLE COVERING THE REMAINDER OF BASIN EXCEPT AREAS OF 
CONVECTION ASSOCIATED WITH LOW PRES AT 10N128W AND TROUGH ALONG 
113W.  RIDGE ALSO SUPPORTS HEALTHY SURFACE HIGH PRES 1026 MB AT 
33N128W.  

APPROACHING WEAK UPPER LEVEL SHORTWAVE TROUGH SUPPORTS COLD 
FRONT WHICH IS EXPECTED TO STALL AND BECOME STATIONARY AS 
SHORTWAVE ALOFT IS FORCED NE BY RIDGE.  

...ELSEWHERE AT THE LOWER LEVELS...
GULF OF TEHUANTEPEC...STRONG NORTHERLY WINDS CROSS THROUGH 
ISTHMUS OF TEHUANTEPEC INCREASING RAPIDLY TO GALE FORCE TONIGHT 
THROUGH WED AND BEYOND.

GULF OF CALIFORNIA...STRONG NW WINDS HAVE BEGUN TO DIMINISH WITH 
SEAS SUBSIDING TO 6-7 FT AS RIDGE WEAKENS SLIGHTLY.  WINDS 
EXPECTED BELOW 20 KT LATER TODAY AND TONIGHT. 

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 STILL CONTINUES 
BUT IS EXPECTED TO DIMINISH BY WED WHILE 8 FT SEAS MAY LINGER 
AND EXTRA DAY.

$$
WALLY BARNES