000
AXPZ20 KNHC 080318
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED AUG 08 2007

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...SPECIAL FEATURE...

A 1009 MB LOW NEAR 14N123W IS EMBEDDED ON A TROPICAL WAVE ALONG 
123W S OF 20N. THIS LOW HAS BEEN PRODUCING LIMITED SHOWER 
ACTIVITY TONIGHT. IT IS STILL POSSIBLE...HOWEVER...THAT THIS 
SYSTEM COULD DEVELOP INTO A TROPICAL DEPRESSION WITHIN THE NEXT 
COUPLE OF DAYS AS IT MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 40 NM OF 
14N124W.

...TROPICAL WAVES...

LARGE TROPICAL WAVE IS ALONG 104W EXTENDING FROM 4N TO 20N. A 
1010 MB LOW PRES IS ALONG THE WAVE AXIS NEAR 17N. MOST OF THE 
CONVECTIVE ACTIVITY ASSOCIATED WITH THE LOW PRES/TROPICAL WAVE 
HAS MOVED NORTH AND AWAY FROM THE LOW LEVEL CENTER TONIGHT. 
SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE MEXICAN 
COAST FROM 19N TO 23N E OF 107W. PUERTO VALLARTA REPORTED HEAVY 
THUNDERSTORMS WITH SUSTAINED WINDS OF NEAR 20 KT. STRONG SELY 
UPPER LEVEL WIND FLOW OVER THE AREA ARE KEEPING THE CONVECTION 
SHEARED FROM THE LOW LEVEL CENTER. THIS SYSTEM IS FORECAST TO 
REACH COOLER SEA SURFACE TEMPERATURES IN ABOUT 24 HOURS. 
THEREFORE...TROPICAL DEVELOPMENT IS NOT ANTICIPATED AS IT MOVES 
WESTWARD AT 10 TO 15 KT.   T

WEAK TROPICAL WAVE IS ALONG 112W FROM 13N TO 4N MOVING W NEAR 
12 KT. CONVECTION IS CONFINED TO THE ITCZ. SCATTERED MODERATE 
CONVECTION IS NOTED ALONG THE ITCZ FROM 10N TO 13N BETWEEN 106W 
AND 112W. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N80W 9N90W 13N100W 10N110W 13N120W 
10N130W 11N140W. SCATTERED MODERATE CONVECTION IS FROM 8N TO 11N 
BETWEEN 95W AND 99W...AND FROM 10N TO 13N BETWEEN 106W AND 112W. 

...DISCUSSION...
AT THE SURFACE...1035 MB HIGH PRES WELL NW OF AREA EXTENDS RIDGE 
SE TO 18N115W. MOSTLY BROKEN TO OVERCAST LOW CLOUDS WITH NO 
CONVECTION COVERS AREA. PRES GRADIENT TIGHTENS BETWEEN RIDGE AND 
LOW PRES NEAR THE MEXICAN COAST AT 17N104W. AS A RESULT...NW 
WINDS OF 20 KT ARE ALREADY BLOWING N OF 20N E OF 115W. THIS 
WEATHER PATTERN WILL PERSIST AL LEAST 24 HOURS. A SFC TROUGH... 
REMNANTS OF A PRIOR TROPICAL DEPRESSION REMAINS ALONG 134W/135W 
FROM 18N TO 26N. 

IN THE UPPER LEVELS...AN UPPER LOW IS JUST ENTERING THE EXTREME 
NW PORTION OF THE AREA WITH AN UPPER TROUGH EXTENDING SW. A FRY 
AIR MASS IS AHEAD OF THE TROUGH AXIS COVERING N OF 15N WEST OF 
130W. BROAD ANTICYCLONIC FLOW CENTERED OVER WESTERN MEXICO 
COVERS THE E EPAC E OF 130W. STRONG ELY FLOW IS FOUND ON SRN 
PERIPHERY OF RIDGE ADVECTING ABUNDANT UPPER LEVEL MOISTURE N OF 
10N. AN UPPER LOW IS NEAR THE GUATEMALA/MEXICO BORDER GENERATING 
A CLUSTER OF MODERATE TO STRONG CONVECTION OVER PARTS OF 
NICARAGUA...HONDURAS AND EL SALVADOR. 

$$
GR