000
AXPZ20 KNHC 220311
TWDEP 

TROPICAL WEATHER DISCUSSION          
NWS NATIONAL HURRICANE CENTER MIAMI FL       
0405 UTC MON APR 22 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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...    
MONSOON TROUGH 09N83W TO 10N98W TO 08N110W THEN ITCZ TO 05N124W
TO 06N133W TO 06N140W. SCATTERED MODERATE CONVECTION WITHIN 
180 NM S OF AXIS FROM 111W TO 130W. 

...DISCUSSION...  
UPPER LEVEL CYCLONE NOW AT 30N138W MOVING AROUND DOWNSTREAM 
RIDGE CREST HAS NEGATIVELY TILTED TROUGH INCH TO 07N119W. VERY
DRY AIR MASS DUE TO STRONG SUBSIDENCE FOLLOW W OF TROUGH AXIS N
OF 08N. SWATH OF CONVECTIVE MOISTURE DEBRIS ADVECTING N ON 50 KT
JET CORE AROUND RIDGE IS CUT OFF BY DRY AIR INTRUSION BY TROUGH
AXIS. MODERATE DIVERGENCE ALOFT NEAR 05N118W PROMPTS SCATTERED
CONVECTION ENHANCED BY ITCZ UPLIFTING AT THE LOWER LEVELS.

UPPER LEVEL ANTICYCLONE FORCED E BY NEGATIVELY TILTED TROUGH NOW
CENTERED AT 15N99W MAINTAINS LARGE DRY STABLE AIR MASS ACROSS
BASIN FROM 12N TO 23N E OF TROUGH AXIS.

...AT THE LOWER LEVELS...
ABUNDANT MOISTURE FROM SOUTH AMERICA MOVING INTO EPAC JUST S OF
MONSOON TROUGH/ITCZ WITH SCATTERED CONVECTION EXTEND ACROSS 
ENTIRE BASIN.

WEAKENING HIGH PRES CENTER 1031 MB AT 41N137W HAS RIDGE TO 
15N105W WITH GENTLE TO MODERATE BREEZE ACROSS ENTIRE BASIN.
SUBSIDING SWELL TO 9 FT LINGER FROM PREVIOUS GULF OF TEHUANTEPEC
GALE EVENT EXPECTED TO DECAY BELOW 8 FT MON. 

$$
WALLY BARNES