000
AXPZ20 KNHC 110844
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED AUG 11 2010

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...ITCZ...

ITCZ AXIS IS ALONG 10N86W TO 12N100W TO 13N115W TO 11N130W TO 
10N140W. SCATTERED MODERATE WITHIN 180 NM S OF AXIS BETWEEN 102W 
AND 110W. 
 
...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE LOCATED WELL W OF THE AREA NEAR 
18N153W OR JUST SE OF THE BIG ISLAND OF HAWAII IS GRADUALLY 
HAVING LESS OF AN IMPACT ON THE AREA WITH THE ASSOCIATED 
UPPER RIDGE EXTENDING INTO THE AREA ALONG 138W FROM 07N TO 20N.
AN UPPER LEVEL TROUGH EXTENDS FROM N OF THE AREA NEAR SAN 
FRANCISCO BAY TO 32N128W THEN CONTINUES AS A SHEAR AXIS TO
22N132W TO 19N140W. VERY DRY AIR UNDER MODERATE TO STRONG 
SUBSIDENCE IS PRESENT ACROSS THE AREA N OF THE ITCZ AND W OF 
122W AS SHOWN IN WATER VAPOR IMAGERY. 

AN EXPANSIVE UPPER LEVEL ANTICYCLONE IS CENTERED OVER NW 
MEXICO NEAR 28N108W WITH AN UPPER RIDGE EXTENDING ACROSS CENTRAL 
BAJA CALIFORNIA TO A LARGE COL NEAR 19N133W. DIFFLUENT UPPER 
LEVEL NORTHEASTERLY WINDS AND OROGRAPHIC LIFT WAS MAINTAINING 
SCATTERED STRONG THUNDERSTORMS ALONG THE SIERRA MADRE 
OCCIDENTAL. THESE SAME WINDS WERE ADVECTING THE MID AND UPPER 
LEVEL MOISTURE WWD TO ALONG 122W N OF THE ITCZ TO 25N. THE 1010 
MB REMNANT LOW OF ESTELLE IS EMBEDDED IN 25 TO 30 KT UPPER LEVEL 
EASTERLY FLOW WHICH HAS SHEARED ALL CONVECTION AWAY FROM THE 
REMNANT LOW CENTER. 

ELSEWHERE AT THE SURFACE...A RIDGE AXIS IS OVER THE NW WATERS 
EXTENDING FROM 1031 MB HIGH PRES CENTERED WELL NW OF THE AREA 
NEAR 44N145W. THE RIDGE ENTERS THE DISCUSSION AREA NEAR 30N140W 
AND CONTINUES THROUGH 26N130W TO 23N115W. DIURNALLY ENHANCED NW 
TO N WINDS OF 20 KT WILL CONTINUE TO OCCUR N OF 24N WITHIN 120 
NM OF THE W COAST OF BAJA CALIFORNIA DURING THE EVENING HOURS 
THROUGH THE NEXT 48 HOURS DUE TO A TIGHT PRES GRADIENT BETWEEN 
THE RIDGE AND TROUGHING IN THE GULF OF CALIFORNIA.

A 1008 MB AREA OF LOW PRES NEAR 18N109W LIES WITHIN 180 NM TO 
THE NE OF THE REMNANT LOW OF ESTELLE. A BURST OF CONVECTION HAS
DEVELOPED NEAR THE LOW OVER THE PAST FEW HOURS. THE REMNANT LOW 
OF ESTELLE IS FORECAST TO MERGE WITH THIS LOW DURING THE NEXT 24 
HOURS WITH THE MERGED SYSTEM DRIFTING SLOWLY EASTWARD THROUGH 48 
HOURS. SOUTHWESTERLY WINDS OF 20 TO 25 KT AT THE SURFACE IS 
FEEDING INTO THIS AREA WHICH IS RESULTING IN 8 TO 11 FT COMBINED 
SEAS. THE SAME CONDITIONS ARE EXPECTED TO PERSIST DURING THE 
NEXT 48 HOURS.

A NEW SET OF LONG PERIOD...17 TO 19 SECONDS...SW SWELL TO 8 FT 
WILL MOVE INTO THE FAR SOUTHERN WATERS E OF 110W LATER TODAY AND 
REACH THE COAST OF MEXICO AND CENTRAL AMERICA BY LATE THU AND 
THU NIGHT.

$$
COBB