000
AXPZ20 KNHC 210314
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE AUG 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 08N84W TO 09N90W TO 15N104W TO 09N119W. 
ITCZ EXTENDS FROM LOW PRES 1010 MB AT 13N129W TO BEYOND 09N140W. 
SCATTERED MODERATE CONVECTION WITHIN 150 NM OF AXIS FROM E OF 
86W.  SCATTERED MODERATE CONVECTION WITHIN 120 NM OF AXIS FROM 
96W TO 108W.  ISOLATED MODERATE CONVECTION WITHIN 90 NM S OF 
AXIS FROM 112W TO 119W.

...DISCUSSION...
BROAD UPPER LEVEL ANTICYCLONE OVER SOUTHERN ARIZONA-MEXICO 
BORDER BRINGS ABUNDANT MOISTURE INTO E PAC N OF 15N E OF 115W.  
SURFACE LOW PRES 1011 MB...REMNANTS OF HECTOR...TOO WEAK TO TAKE 
ADVANTAGE DUE TO THE STABILIZING EFFECT OF COOLER SEA 
TEMPERATURES.  A SECOND SURFACE LOW PRES 1010 MB AT 19N108W DOES 
PROMPT SCATTERED...BUT DIMINISHING...MODERATE CONVECTION BUT IS 
UNDER QUITE AN EASTERLY WIND SHEAR AND LOSING A BATTLE TO STAY 
OVER WARM WATERS AS IT DRIFT FURTHER W.  UPPER LEVEL CYCLONE 
OVER BELIZE AND GUATEMALA CONTRIBUTES MORE MOIST AIR MASS UNTO E 
PAC FROM 10N-15N E OF 115W...JUST ALONG MONSOON TROUGH AXIS WITH 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM OF 
TROUGH AXIS.  ELSEWHERE...BASIN REMAINS VERY DRY W OF 125W AND N 
OF 10N W OF 118W.  MODEL GUIDANCE CHANGES VERY LITTLE FROM THIS 
SCENARIO THROUGH THE NEXT TWO DAYS.  

AT THE LOWER LEVELS...HIGH PRES CENTER 1021 MB AT 29N144W HAS 
RIDGE EXTEND SE TO 18N125W.  BOTH THE AFOREMENTIONED SURFACE LOW 
PRES CENTERS AND A THIRD ONE WITH 1010 MB EMBEDDED IN ITCZ AT 
13N129W ARE EXPECTED TO DISSIPATE WITHIN NEXT TWO DAYS LEAVING 
BASIN WITH NO SIGNIFICANT FEATURES FOR NEXT DAY OR SO.   

STRONG SE WINDS OVER S PAC PROMPT CROSS EQUATORIAL SWELLS 8-9 FT 
PROPAGATING N AND W INTO E PAC S OF 06N W OF 96W.  

$$
WALLY BARNES