000
AXPZ20 KNHC 150340
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI NOV 15 2013

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.

...SPECIAL FEATURE...                                          
GALE FORCE WIND ACROSS GULF OF TEHUANTEPEC EXPECTED TO DIMINISH
BELOW GALE LATE FRI AS SOURCE OF NORTHERLY WINDS ACROSS CHIVELAS
GAP VEERS E AND SE.  SEAS REPORTED EARLIER AS HIGH AS 20 FT 
EXPECTED TO SUBSIDE BELOW 8 FT LATE FRI NIGHT.

LOW PRES 1007 MB AT 12.6N 109.0W FORMED JUST N OF ITCZ AND DRIFT
NW UNDER QUITE A STRONG SOUTHERLY SHEAR ALOFT.  MODELS AGREE ON 
CYCLONE FORMATION AND ITS TIMING AND TRACK BUT DIFFER WIDELY ON
ITS INTENSITY WITH ECWF AND UKMET MUCH BROADER AND WEAKER
CIRCULATION WHILE GFS SPINS SIGNIFICANTLY STRONGER.  GUIDANCE
TURNS CYCLONE N THEN NE INTO GULF OF CALIFORNIA.  STRENGTHENING 
UNDER SUCH SHEAR REMAINS DOUBTFUL...BUT ABUNDANT WARM TROPICAL
MOISTURE AND WARM OCEAN HEAT CONTENT MAY OVERCOMPENSATE SHEAR.
NEVERTHELESS HEAT CONTENT FALLS SHARPLY IN 24 HOURS AND RAPID
WEAKENING MAY THEN OCCUR.      
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
MONSOON TROUGH AXIS FROM 10N86W TO 08N96W THEN ITCZ TO 11N112W TO
07N135W TO BEYOND 08N140W.  SCATTERED MODERATE CONVECTION WITHIN
30 NM N AND 120 NM S OF AXIS FROM 117W TO 123W.
 
...DISCUSSION...
LARGE AMPLITUDE UPPER LEVEL TROUGH FROM 32N102W TO 00N127W BRING
VERY DRY AND STABLE AIR ASS W OF AXIS.  UPPER LEVEL ANTICYCLONE
AT 15N142W EXTEND DRY REGION W BEYOND 140W.  SE OF TROUGH AXIS...
S-SW FLOW ADVECTS ABUNDANT CONVECTIVE DEBRIS MOISTURE NE INTO
CENTRAL MEXICO AND ACROSS GULF OF MEXICO.  

WEAK UPPER LEVEL ANTICYCLONE OVER WESTERN CARIBBEAN ENHANCES
MOIST WARM TROPICAL MOISTURE FLOW INTO CENTRAL AMERICA AND GULF
OF MEXICO.  

...ELSEWHERE AT THE LOWER LEVELS...
VIGOROUS 1032 MB HIGH PRES AT 43N143W PROMPTING FRESH TO STRONG
NORTHEASTERLY TRADES N OF 08N W OF 120W.  HIGH PRES CENTER MOVES 
N AS DEEP LAYER LOW PRES CENTER AND ASSOCIATED COLD FRONT 
APPROACHING CORNER OF BASIN.  TRADES EXPECTED TO DIMINISH BY FRI
NIGHT WITH SEAS SUBSIDING TO 5-6 FT BEFORE BUILDING BACK AS SWELL
TRAIN FROM APPROACHING COLD FRONT REACH BASIN. 

$$
WALLY BARNES