000
AXPZ20 KNHC 220352
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED AUG 22 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 
0215 UTC.

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

MONSOON TROUGH EXTENDS FROM 10N85W TO 13N105W TO 11N120W. ITCZ 
AXIS IS FROM 11N120W TO 1010 MB LOW PRES NEAR 12N132W TO BEYOND 
09N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS 
NOTED FROM 04N TO 06N BETWEEN 88W AND 92W. SIMILAR CONVECTION IS 
N OF THE MONSOON TROUGH TO THE COAST OF CENTRAL AMERICA E OF 
88W. SCATTERED MODERATE CONVECTION CAN BE FOUND FROM 06N TO 09N 
BETWEEN BETWEEN 127W AND 131W...AND NEAR 11N116W.

...DISCUSSION...

THE ANTICYCLONE ALOFT OVER NW MEXICO NEAR 28N111W EXTENDS A 
RIDGE SOUTHEASTWARD ALONG THE COAST OF MAINLAND MEXICO TO THE 
GULF OF TEHUANTEPEC. DIFFLUENT CONDITIONS ASSOCIATED WITH THIS 
RIDGE ARE HELPING TO INDUCE THE CONVECTION ALONG THE SIERRA 
MADRE OCCIDENTAL AS WELL AS THE SHOWER/TSTM ACTIVITY AROUND THE 
1011 LOW PRES LOCATED NEAR 20N109W. THIS LOW PRES IS FORECAST BY 
THE GFS COMPUTER MODEL TO REMAIN NEARLY STATIONARY OVER THE NEXT 
24 HOURS. AN EARLIER ASCAT PASS SHOWED THE CYCLONIC CIRCULATION 
ASSOCIATED WITH THIS LOW BUT WINDS REMAIN IN THE 10 TO 15 KT 
RANGE. ANOTHER ANTICYCLONIC CIRCULATION CENTERED NEAR 22N128W 
HAS A RIDGE EXTENDING SOUTHWESTWARD TO BEYOND 15N14OW. IN 
BETWEEN...THERE IS AN INVERTED TROUGH ALONG 123W FROM 15N TO 
25N. STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS COVERS ROUGHLY 
THE AREA N OF 10N W OF 125W. NE WIND FLOW ALOFT DOMINATES MOST 
OF THE REGION E OF 110W.

ELSEWHERE AT LOW LEVELS...A 1023 MB HIGH PRES IS SITUATED NEAR 
32N145W. A RIDGE EXTENDS FROM THIS HIGH TO NEAR 20N122W. THIS 
SYSTEM WILL MOVE LITTLE DURING THE NEXT 24 HOURS...THEN WILL BE 
ABSORBED BY A STRONGER HIGH PRES LOCATED WELL NW OF THE FORECAST 
AREA. MODERATE TRADE WINDS ARE NOTED AROUND THE SOUTHERN 
PERIPHERY OF THE RIDGE PER THE MOST RECENT ASCAT PASS.
 
THE REMNANTS OF HECTOR ARE STILL SEEN ON SATELLITE PICTURES NEAR 
22N115W. A 1010 LOW PRES LOCATED NEAR 12N132W IS GENERATING SOME 
SHOWER ACTIVITY AND WILL MOVE WSW AT 5-10 KT OVER THE NEXT 24 
HOURS. THE WEAK LOW PRES THAT WAS ALONG THE MONSOON TROUGH NEAR 
13N109W HAS DISSIPATED. 

CROSS-EQUATORIAL SE TO S SWELL TO 8 FT WILL LIE OVER THE SOUTH 
WATERS MAINLY S OF 05N BETWEEN 115W AND 132W OVER THE NEXT FEW 
DAYS. AN EARLIER ASCAT PASS SHOWED AN AREA OF SE WINDS OF 20 TO 
25 KT S OF 06N BETWEEN 120W AND 128W.   

$$
GR