000
AXPZ20 KNHC 122120
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 12 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...THE ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE EXTENDS FROM 08N79W TO 06N90W 
TO 06N107W WHERE IT BECOMES DIFFUSE. A 1011 MB LOW IS NEAR 
11N123W WHERE THE ITCZ THEN RESUMES TO 08N131W TO 10N140W. 
SCATTERED MODERATE WITHIN 120 NM N OF THE AXIS BETWEEN 130W AND 
135W.

...DISCUSSION...

S OF 20N BROAD UPPER LEVEL ANTICYCLONIC FLOW...DRIVEN BY LATENT 
HEAT RELEASE FROM CONVECTION IN THE ITCZ W OF 136W AND 
CONVECTION ASSOCIATED WITH THE SURFACE LOW NEAR 11N123W REACHES 
TO 110W. AN UPPER LEVEL ANTICYCLONE IS OVER THE 
CARIBBEAN...FUELED BY LATENT HEAT RELEASE FROM CONVECTION 
ASSOCIATED WITH A TROPICAL WAVE OVER THE SW CARIBBEAN...AND 
CONVECTION FROM HURRICANE PAULA...LOCATED NEAR 19.2N 86.0W AT 5 
PM EDT. THE DISTANCE BETWEEN THESE TWO UPPER LEVEL FEATURES HAS 
DECREASED OVER THE PAST 48 HOURS...RESULTING IN A DEFORMATION OF 
THE TROUGH BETWEEN THE FEATURES. THE DEFORMATION OF THIS TROUGH 
WILL CONTINUE OVER THE NEXT 24 HOURS...AND RESULT IN A CUTOFF 
LOW WITHIN THE NEXT 24 HOURS...WHICH WILL THEN GRADUALLY SPIN 
DOWN WITHIN 72 HOURS. 

AT THE LOW LEVELS...SURFACE HIGH PRES 1027 MB IS NEAR 40N132W. 
THE PRESSURE GRADIENT BETWEEN THIS HIGH PRESSURE CENTER...AND 
LOWER PRESSURE OF THE ITCZ...IS SUPPORTING NE TRADES AT 20 KT 
WITH SEAS TO 10 FT OVER THE WATERS FROM 12N TO 20N W OF 123W. 

GAP WINDS...THE CIRCULATION AROUND HURRICANE PAULA WILL INCREASE 
N TO NE WINDS ACROSS THE SW GULF OF MEXICO. THIS WILL RESULT IN 
INCREASED NORTHERLY WINDS FUNNELING THROUGH THE CHIVELA 
PASS...WHICH WILL INCREASE WINDS TO 20 TO 25 KT BY TONIGHT OVER 
AND JUST DOWNSTREAM OF THE GULF OF TEHUANTEPEC. AS A COLD FRONT 
REACHES THE SW GULF OF MEXICO WED...WINDS FUNNELING THROUGH THE 
CHIVELA PASS WILL FURTHER INCREASE. THIS WILL FURTHER INCREASE 
WINDS OVER THE GULF OF TEHUANTEPEC TO MINIMAL GALE 
WED...STRENGTHENING TO 30 TO 40 KT WED NIGHT AND CONTINUING 
THROUGH AT LEAST FRI MORNING. 
 
$$
AL