000
AXPZ20 KNHC 260922
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JUL 26 2007

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 DALILA IS CENTERED NEAR 20.9N 113.1W AT 26/0900 
UTC MOVING WNW AT 8 KT. MAXIMUM SUSTAINED WIND SPEED HAS 
INCREASED TO 45 KT WITH GUSTS TO 55 KT. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 1000 MB. SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. 
DALILA HAS TAKEN THE SHAPE OF A CLASSIC CURVED BAND THIS EARLY 
MORNING WITH EVEN SOME WRAPPING NEAR ITS EARLIER EXPOSED 
LOW-LEVEL CENTER. SCATTERED MODERATE CONVECTION APPEARS CONFINED 
TO THIS MAIN BAND GENERALLY FROM 18N-22N BETWEEN 111W-114W. 
DESPITE THE SLIGHT STRENGTHENING...THE OVERALL WEAKENING PROCESS 
IS EXPECTED TO RESUME AS IT ENCOUNTERS COOLER SST'S AND A MORE 
STABLE AIRMASS WITH DEGENERATION TO A REMNANT LOW FORECAST IN 
ABOUT 2 DAYS. 

...TROPICAL WAVES...
TROPICAL WAVE HAS BEEN ADJUSTED ALONG 96W/97W N OF 6N MOVING W 
15-20 KT. EARLIER...THIS WAVE WAS BE TRACKED AS THE LEADING EDGE 
OF A MOISTURE SURGE. HOWEVER...THE WAVE AXIS HAS BECOME BETTER 
DEFINED OVER THE PAST FEW HOURS WITH SATELLITE IMAGERY DEPICTING 
A BROAD AREA OF LOW-LEVEL TURNING. SCATTERED SHOWERS AND TSTMS 
HAVE DEVELOPED AND BEEN EXPANDING WITHIN 120 NM EITHER SIDE OF 
THE WAVE AXIS. SHIP DATA AND A 02Z QSCAT PASS CONFIRM THAT THIS 
TURNING IS AT THE SFC...ALL LEADING TO THE UPDATED PSN.  

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N83W 11N109W 13N119W 11N130W 
12N140W. SCATTERED MODERATE FROM 6N-8N BETWEEN 90W-97W AND FROM 
12N-13N BETWEEN 121W-123W. 

...DISCUSSION...

W OF 120W...
UPPER CONFLUENT FLOW...ASSOCIATED WITH AN UPPER HIGH CENTERED 
NEAR 27N128W AND SWLY FLOW TO THE E OF A SHARP TROUGH AXIS...IS 
PRODUCING ABUNDANT DRY STABLE AIR ALOFT. THIS STABLE AIRMASS IS 
LIMITING ANY DEEP CLOUD FORMATION...EVEN ALONG THE ITCZ. A QSCAT 
PASS AROUND 02Z SHOWED LIGHT TO MODERATE N-NELY TRADES...WITH 
WINDS TO 20 KT CONFINED ROUGHLY N OF 27N BETWEEN 124W AND 130W 
OR SO. THE TRADES ARE EXPECTED TO WEAKEN EVEN FURTHER OVER THE 
NEXT COUPLE OF DAYS AS THE GRADIENT SLACKENS BETWEEN DALILA AND 
HIGH PRES TO THE NW OF THE REGION.

E OF 120W... 
THIS PART OF THE EPAC IS CONSIDERABLY MORE MOIST...WHICH IS 
RATHER TYPICAL. EXTENSIVE ELY UPPER FLOW...ON THE SRN PERIPHERY 
OF AN UPPER HIGH IN THE SE GULF...AND UPPER DIFFLUENCE...BETWEEN 
A TROUGH TO THE NE OF DALILA ABOVE MEXICO AND RIDGING OVER THE 
SW U.S...ARE THE MAIN CONTRIBUTIONS TO THE OVERALL MOISTENED 
ATMOSPHERE. IN ADDITION TO THE UPPER MOISTURE IN PLACE... 
LOW-LEVEL LIFT NEAR TROPICAL STORM DALILA...THE ITCZ...AND 
TROPICAL WAVE IN THE REGION ARE PRODUCING POCKETS OF CONVECTION. 
DEBRIS MOISTURE FROM THESE AREAS ARE ENHANCING THE UPPER 
MOISTURE POOL. 

$$
CANGIALOSI