000
AXPZ20 KNHC 292157
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JUL 29 2007

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 92W N OF 5N MOVING W NEAR 15 KT. WEAK 
CYCLONIC TURNING IS NOTED ALONG THE WAVE AT 8N WHERE THERE IS A 
CLUSTER OD MODERATE CONVECTION. THE WAVE IS GENERATING SOME 
SHOWER ACTIVITY ALONG THE GUATEMALA/MEXICO BORDER. 

LOW PRES 11N116W 1008 MB IS ASSOCIATED WITH A TROPICAL WAVE 
ALONG 116W FROM 4N TO 16N. THE SYSTEM HAS MOVED W NEAR 15 KT 
OVER THE PAST 24 HOURS. SCATTERED MODERATE TO STRONG CONVECTION 
IS FLARING W OF THE ESTIMATED CENTER...WITHIN 45 NM OF 11N117W. 
SCATTERED MODERATE CONVECTION IS NOTED ELSEWHERE FROM 7N TO 14N 
BETWEEN 114W AND 119W. THIS LOW HAS THE POSSIBILITY OF BECOMING 
A TROPICAL CYCLONE OVER THE NEXT FEW DAYS AS IT CONTINUES TO 
MOVE WESTWARD AROUND 10 TO 15 KT. 

...ITCZ...
ITCZ AXIS ALONG 9N78W 10N90W 12N105W 9N120W 10N140W. SCATTERED 
MODERATE ISOLATED STRONG FROM 7N TO 14N BETWEEN 90W AND 110W. 
SCATTERED MODERATE TO STRONG WITHIN 45 NM OF 11N117W ASSOCIATED 
WITH A 1008 MB LOW NEAR 11N116W AT 29/1800 UTC. SCATTERED 
MODERATE ELSEWHERE FROM 7N TO 14N BETWEEN 114W AND 119W. 

...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. THE SFC PRES GRADIENT REMAINS MODEST 
BETWEEN A 1026 MB HIGH NEAR 35N146W AND THE REMNANT SWIRL OF 
DELILA...ANALYZED 1012 MB NEAR 24N122W. ONCE AGAIN...AN EARLIER 
QUIKSCAT PASS SHOWED WINDS OF 20 KT TO THE W SIDE OF THE 
LOW-LEVEL SWIRL THAT IS EXPECTED TO FURTHER WEAKEN TO AN OPEN 
TROUGH TONIGHT. ELSEWHERE...TRADES REMAIN MODERATE...MOSTLY 
BELOW 20 KT...AND LITTLE CHANGE IS EXPECTED OVER THE NEXT COUPLE 
OF DAYS. 

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 ANY DEVELOPMENT OF THE AFOREMENTIONED SFC LOW INTO A 
TROPICAL CYCLONE. AT THE SAME TIME...THESE WINDS ARE ENHANCING 
CONVECTION ALONG THE ITCZ.  

$$
GR