000
AXPZ20 KNHC 140950
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU AUG 14 2008

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 
0915 UTC.

...SPECIAL FEATURE...
TROPICAL STORM ISELLE AT 17.6N 108.6W 1003 MB AT 0900 UTC MOVING 
W NW OR 290 DEG AT 09 KT. MAXIMUM SUSTAINED WINDS 40 GUSTS TO 50 
KT. NUMEROUS STRONG CONVECTION IS NOTED WITHIN 60 NM OF 
17N108.5W. ISELLE IS FORECAST TO REMAIN A TROPICAL STORM FOR 
ABOUT 3 DAYS AND THEN WEAKEN AS IT MOVES OVER COOLER WATERS. SEE 
THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADER 
MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS.

...TROPICAL LOWS...

LOW PRES IS ANALYZED AT 14N120W AT 1007 MB. THIS LOW HAS BEEN 
MOVING W AT 08 KT OVER THE PAST TWO DAYS AND IS EXPECTED TO 
CONTINUE MOVING W AT ABOUT 08 KT. THE LOW LEVEL CENTER IS 
SOMEWHAT EXPOSED NE OF A BURST OF NUMEROUS STRONG CONVECTION 
NOTED WITHIN 30 NM OF 13N121W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION SURROUNDS THE CONVECTIVE BURST ELSEWHERE 
WITHIN 60 NM OF LINE FROM 15N123W TO 12N121W. THIS LOW HAS THE 
POTENTIAL TO DEVELOP INTO A TROPICAL CYCLONE OVER THE NEXT FEW 
DAYS.

REMNANT LOW PRES OF HERNAN IS CENTERED NEAR 17N139W AND 
ESTIMATED AT 1011. SSMI DATA INDICATES WINDS ARE STILL 20 TO 30 
KT WITHIN 360 NM OF CENTER OVER THE NE SEMICIRCLE. THE 
CONDITIONS ASSOCIATED WITH THIS REMNANT LOW ARE EXPECTED TO MOVE 
W OF THE AREA BY 48 HOURS. 

...TROPICAL WAVES... 

A TROPICAL WAVE IS ALONG 100W AT THE MOMENT AND HAS BEEN MOVING 
W AT ABOUT 15 KT THE PAST 24 HOURS. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS NOTED WITHIN 150 NM OF THE WAVE AXIS FROM 
08N TO 13N.

A TROPICAL WAVE IS ALONG 89W AND HAS BEEN MOVING W AT ABOUT 17 
KT THE PAST 24 HOURS. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED WITHIN 15 NM OF 11N91W BUT CONVECTION WAS 
ENHANCED EARLIER WELL INLAND OVER THE HONDURAS AND GUATEMALA 
BORDER.

...ITCZ...

THE ITCZ AXIS IS ALONG 07N78W TO 07N94W TO 12N110W TO 13N133W TO 
11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 30 NM OF 06N78W AND ALSO WITHIN 90 NM EITHER SIDE OF LINE 
FROM 11N91W TO 11N101W AND ALSO FROM 11N106W TO 12N114W. 

...DISCUSSION...

AN UPPER TROUGH EXTENDS SW INTO THE DISCUSSION AREA ALONG 
32N134W TO 23N140W. A SMALL UPPER ANTICYCLONE IS IMMEDIATELY NW 
OF THE TROUGH NEAR 35N138W AND MOVING E WITH TIME WHICH 
SURROUNDED BY UPPER LEVEL MOISTURE WITHIN 240 NM OF CENTER.
ANOTHER UPPER LEVEL ANTICYCLONE IS CENTERED NEAR CALIFORNIA NEAR 
35N118W WITH A RIDGE EXTENDING SSW ALONG 32N124W TO 26N126W.
A SMALL UPPER CYCLONE HAS FORMED NEAR 27N120W AND ANOTHER NEAR 
23N132W. AN UPPER RIDGE EXTENDS SW ACROSS OLD MEXICO TO 
22N117W...THEN BECOMES SOMEWHAT ILL-DEFINED BUT APPEARS TO 
CONTINUE SW TO NEAR 13N126W AND ENHANCES CONVECTION ASSOCIATED 
WITH THE LOW PRES AT 14N120W.

DIFFLUENCE UNDER THIS RIDGE ENHANCED CONVECTION OVER NORTHERN 
OLD MEXICO WITH SOME OF THE DEBRIS MOISTURE ADVECTED W OVER THE 
DISCUSSION AREA N OF 20N BETWEEN 105W AND 115W. THE UPPER LEVELS 
APPEAR VERY DRY W OF 131W. AT THE LOW LEVELS A RIDGE EXTENDS 
FROM 32N138W TO 22N115W. LOCALLY OVERCAST STRATOCUMULUS IS NOTED 
N OF 18N W OF 117W.  

NE FLOW ALOFT IS NOTED OVER THE DISCUSSION AREA S OF 13N PUSHING 
DEBRIS MOISTURE SW TO THE EQUATOR E OF 125W.

$$
NELSON