000
AXPZ20 KNHC 212135
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC SAT SEP 21 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS FROM 09N82W TO 14N96W TO 12N100W TO 
11N135W...THEN TRANSITIONS TO AN ITCZ TO 11N140W. SCATTERED 
MODERATE CONVECTION FROM 07N TO 10N BETWEEN 82W AND 97W.

...DISCUSSION...

WATER VAPOR IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE MAINLY W 
OF 110W ASSOCIATED WITH A LARGE MID-LEVEL ANTICYCLONE ANCHORED 
NEAR 23N117W THAT DOMINATES THE REGION. DRY STABLE MID-LEVEL AIR 
IS INHIBITING CONVECTION IN THE TROPICS W OF 100W. A WEAKENING 
COLD FRONT EXTENDS FROM 32N123W TO 25N145W. THE FRONT WILL STALL 
TONIGHT THEN DISSIPATE SUN. HIGH PRES WILL BUILD EASTWARD N OF 
THE FRONT TONIGHT AND SUN...TIGHTENING THE PRES GRADIENT N OF 
30N AND ALLOWING NLY WINDS TO INCREASE...WITH SEAS EXPECTED TO 
BUILD TO 8 FT NEAR THE COAST OF NORTHERN BAJA CALIFORNIA SUN. 
WEAK PRES PATTERN WILL PERSIST ELSEWHERE ACROSS THE AREA. EXPECT 
SUBSIDENCE NEAR THE CONVERGENCE ZONE TO EASE OFF THIS EVENING... 
ALLOWING CONVECTION TO INCREASE IN AEREAL COVERAGE SUN AND MON.
 
$$
MUNDELL