000
AXPZ20 KNHC 101007
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE AUG 10 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 
0830 UTC.

...SPECIAL FEATURE...

AT 10/0900 UTC...THE CENTER OF TROPICAL DEPRESSION ESTELLE IS 
LOCATED NEAR 17.4N 113.4W MOVING TOWARD THE SOUTHWEST OR 235 
DEGREES AT 2 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. 
MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT. ESTELLE 
HAS SHOWN ONLY ONE SMALL BURST OF DEEP CONVECTION IN THE 
SOUTHWEST QUADRANT OF THE CYCLONE DURING THE EVENING. STRONG 
SOUTHEASTERLY VERTICAL SHEAR CONTINUES AND FURTHER WEAKENING IS 
EXPECTED WITH ESTELLE BECOMING A POST TROPICAL REMNANT LOW 
TODAY. SEE THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...ITCZ...

THE ITCZ AXIS IS ALONG 09N79W TO 18N105W...THEN A BREAK IN THE 
ITCZ...RESUMING AGAIN AT 14N116W TO 10N140W. SCATTERED MODERATE 
ISOLATED STRONG WITHIN 120 NM N OF AXIS AND WITHIN 360 NM S OF 
AXIS BETWEEN 86W AND 105W.
 
...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS LOCATED NEAR 16N140W. VERY DRY AIR 
UNDER MODERATE TO STRONG SUBSIDENCE IS PRESENT ACROSS THE AREA N 
OF THE ITCZ AND W OF 121W AS SHOWN IN BOTH THE WATER VAPOR AND 
TOTAL PRECIPITABLE WATER SATELLITE IMAGERY. A BROAD UPPER LEVEL 
TROUGH ENTERS THE FORECAST AREA NEAR 32N127W AND CONTINUES SW TO 
NEAR 22N140W. THIS AREA OF TROUGHINESS SEPARATES THE UPPER 
ANTICYCLONE NOTED ABOVE FROM ANOTHER UPPER LEVEL ANTICYCLONE 
LOCATED OVER N CENTRAL MEXICO NEAR 25N105W WITH A RIDGE AXIS 
EXTENDING W INTO THE E PACIFIC TO NEAR 23N124W. TROPICAL 
DEPRESSION ESTELLE IS EMBEDDED IN THE FAIRLY STRONG UPPER LEVEL 
SOUTHEASTERLY FLOW TO THE SW OF THIS ANTICYCLONE...WHICH ALONG 
WITH THE MARGINAL THERMODYNAMICAL ENVIRONMENT HAS WEAKENED THE 
SYSTEM TO A MARGINAL TROPICAL CYCLONE.

AT THE SURFACE...A RIDGE DOMINATES THE NORTHERN WATERS 
ORIGINATING FROM 1030 MB HIGH PRES CENTERED WELL NW OF THE AREA 
NEAR 38N145W ENTERING THE DISCUSSION AREA NEAR 28N140W AND 
CONTINUING THROUGH 25N115W. A WEAK SURFACE TROUGH EXTENDING FROM 
30N130W TO 31N140W HAS NUDGED THE RIDGE MORE TO THE S...ALTHOUGH 
THE TROUGH IS EXPECTED TO DISSIPATE AS IT MOVES S OF 30N TODAY.  
THERE IS NO SIGNIFICANT DEEP CONVECTION ASSOCIATED WITH THIS 
TROUGH. DIURNALLY ENHANCED NW WINDS OF 20 KT WILL OCCUR WITHIN 
120 NM OF THE W COAST OF BAJA CALIFORNIA FROM 24N TO 28N... 
MAINLY DURING THE EVENING HOURS...THROUGH THE NEXT 48 HOURS.

THE MONSOON TROUGH CONTINUES TODAY TO BE WELL DEFINED AS THE 
CONVERGENCE LINE BETWEEN THE MODERATE SOUTHWESTERLIES AND EAST 
TO NORTHEASTERLIES.  IT IS RESPONSIBLE FOR NUMEROUS AREAS OF 
DEEP CONVECTION BETWEEN 90W AND 105W. SW WINDS OF 20 TO 25 KT 
CONTINUE S OF THE ITCZ TO 09N BETWEEN 100W AND 122W WITH 
COMBINED SEAS OF 8 TO 12 FT. THIS OVERALL WEATHER PATTERN WILL 
PERSIST DURING THE NEXT FEW DAYS. 

NO SIGNIFICANT SWELL EVENTS ARE OCCURRING CURRENTLY OR EXPECTED 
TO AFFECT THE AREA DURING THE NEXT TWO DAYS.  HOWEVER...BY LATE 
THURSDAY SOME 8 TO 9 FT SW SWELL SHOULD BEGIN CROSSING THE 
EQUATOR IN THE EASTERN PORTION OF THE REGION.

$$
LANDSEA/LEWITSKY