000
AXPZ20 KNHC 090952
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON AUG 09 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 09/0900 UTC...THE CENTER OF TROPICAL STORM ESTELLE WAS 
LOCATED NEAR 17.7N 112.1W MOVING TOWARD THE WEST OR 270 DEGREES 
AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1001 MB. MAXIMUM 
SUSTAINED WINDS REMAIN AT 40 KT WITH GUSTS TO 50 KT. ESTELLE'S 
CONVECTION CONTINUES TO PULSE THIS EVENING...AS MODERATE 
SOUTHEASTERLY VERTICAL SHEAR IS CAUSING THE LOW-LEVEL CENTER TO 
BE ON THE SOUTHEAST SIDE OF THE DEEP CONVECTION.  FURTHER 
WEAKENING IS EXPECTED AND ESTELLE IS FORECAST TO BECOME A 
TROPICAL DEPRESSION WITHIN THE NEXT DAY. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC 
FOR MORE DETAILS.

...TROPICAL WAVE...

THE SOUTHERN EXTENT OF A TROPICAL WAVE IS N OF 14N ALONG 
96W...PRIMARILY OVER SOUTHERN MEXICO. THIS MAY BE ENHANCING SOME 
OF THE DEEP CONVECTION OCCURING ALONG THE MONSOON TROUGH JUST 
SOUTH OF THE MEXICO AND CENTRAL AMERICA COAST.  VARIOUS MODEL 
SOLUTIONS TRY TO DEVELOP AN AREA OF LOW PRES ALONG THIS WAVE 
DURING THE NEXT FEW DAYS ALTHOUGH ANY DEVELOPMENT SHOULD BE SLOW 
TO OCCUR DUE TO STRONG UPPER-LEVEL WINDS. THEREFORE THERE IS A 
LOW CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE WHILE IT 
MOVES LITTLE DURING THE NEXT 48 HOURS.

...ITCZ...

THE ITCZ AXIS IS LOCATED ALONG AN AXIS EXTENDING FROM 11N86W TO 
14N95W TO 17N103W TO 12N120W TO 10N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 60 NM N OF AXIS 
AND WITHIN 180 NM S OF AXIS E OF 120W.
 
...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS LOCATED NEAR 17N134W. VERY DRY AIR 
UNDER MODERATE TO STRONG SUBSIDENCE IS PRESENT ACROSS THE AREA N 
OF THE ITCZ AND W OF 117W AS SHOWN IN THE WATER VAPOR CHANNEL IN 
THE GEOSTATIONARY IMAGERY AS WELL AS THE TOTAL PRECIPITABLE 
WATER IMAGERY FROM THE POLAR ORBITING SATELLITES.  A SHARP UPPER 
LEVEL TROUGH ENTERS THE FORECAST AREA NEAR 32N120W AND CONTINUES 
ALMOST DUE S TO NEAR 15N123W. THE AREA OF TROUGHINESS SEPARATES 
THE UPPER ANTICYCLONE NOTED ABOVE FROM ANOTHER UPPER LEVEL 
ANTICYCLONE LOCATED OVER THE EASTERN MEXICAN BORDER NEAR 22N97W 
WITH A RIDGE AXIS EXTENDING WNW INTO THE E PACIFIC TO NEAR 
21N118W. TROPICAL STORM ESTELLE IS EMBEDDED IN THE FAIRLY STRONG 
UPPER LEVEL SOUTHEASTERLY FLOW TO THE SW OF THIS ANTICYCLONE AND 
E OF THE AFOREMENTIONED TROUGH...BOTH OF WHICH HAVE TAKEN THEIR 
TOLL ON THE TROPICAL CYCLONE.

AT THE SURFACE...A RIDGE DOMINATES THE NORTHERN WATERS 
ORIGINATING FROM 1030 MB HIGH PRES CENTERED WELL NW OF THE AREA 
NEAR 36N145W ENTERING THE DISCUSSION AREA AT 32N138W AND 
CONTINUING THROUGH 19N116W. AN AREA OF NE 20 KT TRADES IS 
BELIEVED TO HAVE DEVELOPED FROM 14N TO 18N W OF 135W...WHICH 
WILL LIKELY PERSIST IN THE SAME GENERAL AREA THROUGH 48 HOURS. 
ALSO...DIURNALLY ENHANCED NW WINDS TO 20 KT WILL OCCUR WITHIN 
120 NM W OF THE W COAST OF BAJA CALIFORNIA FROM 24N TO 
27N...MAINLY DURING THE EVENING HOURS...THROUGH THE NEXT TWO 
DAYS.

A WELL-DEVELOPED MONSOON TROUGH IS RESPONSIBLE FOR THE 
WIDESPREAD AREA OF DEEP CONVECTION FROM AROUND 115W EASTWARD TO 
CENTRAL AMERICA.  SOUTH OF THE ITCZ...SW WINDS OF 20 TO 25 KT 
BETWEEN 100W AND 125W AS CAPTURED BY THE EARLIER ASCAT 
SCATTEROMETER PASS AT 0514 UTC. COMBINED SEAS ARE 8 TO 11 FT 
ACROSS THIS SAME AREA DUE TO THE COMBINATION OF LONG PERIOD SW 
SWELL AND FRESHLY GENERATED WIND SEAS. THIS OVERALL WEATHER 
PATTERN WILL PERSIST DURING THE NEXT FEW DAYS. 

CROSS EQUATORIAL SW SWELLS DOMINATING THE MAJORITY OF THE 
SOUTHERN AND EASTERN PORTIONS OF THE FORECAST WATERS WILL 
GRADUALLY DECAY THROUGH EARLY ON WED. A NEW SWELL TRAIN WITH 
PERIODS OF 14 TO 16 SECONDS IS EXPECTED TO CROSS THE EQUATOR 
BETWEEN 105W AND 125W LATER TODAY...THEN WILL SPREAD OVER MOST 
OF THE BASIN S OF 13N TO 15N BY LATE TUE.

$$
LANDSEA/LEWITSKY