000
AXPZ20 KNHC 300320
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON JUL 30 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 
0300 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 93W N OF 5N MOVING W NEAR 15 KT. WEAK 
CYCLONIC TURNING IS NOTED ALONG THE WAVE AT 8N. THE WAVE IS 
GENERATING SOME SHOWER/TSTMS ACTIVITY OVER THE ISTHMUS OF 
TEHUANTEPEC. A CLUSTER OF MODERATE CONVECTION IS JUST AHEAD OF 
THE WAVE AXIS NEAR 8N95W. 

LOW PRES 11N116W 1008 MB IS ASSOCIATED WITH A TROPICAL WAVE 
ALONG 116W FROM 4N TO 16N. THE SYSTEM IS MOVING W 10 TO 15 KT.
SCATTERED MODERATE TO STRONG CONVECTION IS FLARING W OF THE 
ESTIMATED CENTER...WITHIN 60 NM OF 12N118W. SCATTERED MODERATE 
CONVECTION IS NOTED ELSEWHERE FROM 9N TO 14N BETWEEN 117W AND 
121W. UPPER LEVEL WINDS ARE PRESENTLY UNFAVORABLE FOR 
DEVELOPMENT. 

...ITCZ...
ITCZ AXIS ALONG 8N80W 10N92W 13N105W 11N120W 10N140W. SCATTERED 
MODERATE ISOLATED STRONG FROM 10N TO 14N BETWEEN 104W AND 111W. 

...DISCUSSION...
W OF 120W...
ABUNDANT DRY AIR IN THE MID AND UPPER LEVELS CONTINUES TO 
DOMINATE THIS PORTION OF THE EPAC SUPPRESSING ANY CONVECTION... 
EVEN ALONG THE ITCZ. A SHORT WAVE TROUGH IS ALONG 130W N OF 27N. 
THE SFC PRES GRADIENT REMAINS MODEST BETWEEN A 1027 MB HIGH 
NEAR 35N146W AND THE REMNANT SWIRL OF DALILA...ANALYZED 1011 MB 
NEAR 24N122W AT 30/0000Z. THIS LOW-LEVEL SWIRL IS EXPECTED TO 
FURTHER WEAKEN TO AN OPEN TROUGH TONIGHT. ELSEWHERE...TRADES 
REMAIN MODERATE. NELY WINDS OF 20 KT AND SEAS T0 8 FT ARE JUST 
BEGINNING TO AFFECT THE EXTREME NW PORTION.  

E OF 120W...
AN UPPER ANTICYCLONE IS NEAR 24N119W. ELY WIND FLOW...TO THE S 
OF THIS LARGE SCALE RIDGE...IS TRANSPORTING A GOOD AMOUNT OF 
MOISTURE ACROSS THE TROPICAL BELT. THESE WINDS ARE STRONG ENOUGH 
TO INHIBIT THE DEVELOPMENT OF THE AFOREMENTIONED SFC LOW INTO A 
TROPICAL CYCLONE. AT THE SAME TIME...THESE WINDS ARE ENHANCING 
CONVECTION ALONG THE ITCZ.  

$$
GR