000
AXPZ20 KNHC 262152
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU JUL 26 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 
2130 UTC.

...SPECIAL FEATURE...
TROPICAL STORM DALILA AT 22.2N 115.2W AT 26/2100 UTC MOVING W NW 
AT 8 KT. MAXIMUM SUSTAINED WIND SPEED 40 GUSTS TO 50 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE 1002 MB. DALILA IS RAPIDLY 
BECOMING A TIGHT SWIRL OF LOW CLOUDS AS IT MOVES OVER COOLER 
WATER. THERE ARE STILL SOME PATCHES OF DEEP CONVECTION BUT THE 
TOPS ARE WARMING FAST. DALILA'S CIRCULATION IS EXPECTED TO BE 
OVER 22 TO 23 DEGREE CELSIUS WATERS SOON...SO A CONTINUED 
WEAKENING TREND IS ANTICIPATED. IT COULD BECOME A REMNANT LOW AS 
EARLY AS TOMORROW. SCATTERED MODERATE FROM 21N TO 25N BETWEEN 
112W AND 116W. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 98W N OF 5N MOVING W 10 T0 15 KT. SCATTERED 
MODERATE CONVECTION FROM 7N TO 14N BETWEEN 92W AND 100W. 

...ITCZ...
ITCZ AXIS ALONG 8N78W 12N95W 13N112W 11N130W 11N140W. SCATTERED 
MODERATE CONVECTION WITHIN 140 NM S OF AXIS E OF 85W. SIMILAR 
CONVECTION IS FOUND FROM 7N TO 14N BETWEEN 92W AND 100W. A 
DIFFLUENT PATTERN ALOFT IS ENHANCING THIS CONVECTIVE ACTIVITY.

...DISCUSSION...
AN ELONGATED UPPER RIDGE AXIS FROM 32N120W TO 11N140W IS 
BLOCKING THE MOVEMENT OF STRONG UPPER LEVEL TROUGH DRAGGING SW 
FROM A CYCLONIC VORTEX AT 30N140W. THIS RIDGE IS PRODUCING 
ABUNDANT DRY STABLE AIR ALOFT W OF 120W. THIS STABLE AIRMASS IS 
LIMITING ANY DEEP CLOUD FORMATION...EVEN ALONG THE ITCZ. 
INCREASING SWLY FLOW AHEAD OF THE AFOREMENTIONED UPPER TROUGH IS 
BRINGING SOME UPPER LEVEL MOISTURE INTO THE AREA N OF 15N W OF 
135W.  

LARGE ANTICYCLONE REMAINS OVER THE YUCATAN PENINSULA PRODUCING 
AN EXTENSIVE ELY UPPER FLOW OVER CENTRAL AMERICA AND THE EPAC 
E OF 110W. UPPER DIFFLUENCE BETWEEN A TROUGH OVER COAHUILA IN 
MEXICO AND RIDGING OVER THE SW U.S. IS HELPING TO GENERATE 
SCATTERED MODERATE CONVECTION ALONG THE SIERRA MADRE MOUNTAINS 
ON THE WEST SIDE OF MEXICO.  

AT THE SURFACE...
DALILA REMAINS THE MAIN FEATURE IN TODAYS MAP. MINOR INTRUSION 
OF MODERATE N WIND ALONG BAJA CALIFORNIA W COAST WITH 8 FT SEAS 
INTRUDING AS FAR S AS 25N. EVENT LASTING LESS THAN 12 HRS. 
BROKEN TO OVERCAST STRATOCUMULUS CLOUDS COVER THE AREA N OF 20N 
WEST OF 120W UNDER THE INFLUENCE OF A SURFACE RIDGE. 

$$
GR