000
AXPZ20 KNHC 242129
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUL 24 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.

...SPECIAL FEATURE...

TROPICAL STORM DALILA CENTERED NEAR 17.3N 110.2W...OR ABOUT 100 
NM SSE OF SOCORRO ISLAND...AT 24/2100 UTC MOVING NNW AT 6 KT.  
MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT.  
ESTIMATED MINIMUM CENTRAL PRES 997 MB. THE CONVECTIVE STRUCTURE 
OF DALILA IS FINALLY LOOKING LIKE A HEALTHIER TROPICAL 
CYCLONE...WITH VERTICAL SHEAR DOWN TO 10-15 KT. THE LOW-LEVEL 
CENTER APPEARS PARTIALLY EXPOSED JUST NE OF A LARGE CLUSTER OF 
DEEP CONVECTION...AND A QUASI-CONNECTED BAND WRAPS FROM THIS 
CLUSTER AROUND THE N AND NE SIDE OF THE SYSTEM. NUMEROUS STRONG 
CONVECTION IS WITHIN 240 NM SW SEMICIRCLE AND SCATTERED 
MODERATE/STRONG IS WITHIN 360 NM NE SEMICIRCLE. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC 
FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS S OF PANAMA ALONG 81W N OF 4N MOVING W 
15-20 KT. THE WAVE IS MOST PROMINENT OVER THE WRN CARIBBEAN WITH 
NO SIGNIFICANT CIRCULATION NOTED OVER THE PACIFIC WATERS. THE 
WAVE MAY BE ENHANCING LOW-LEVEL CONVERGENCE ALONG THE ITCZ S OF 
COSTA RICA.

TROPICAL WAVE EXTENDS S OF THE GULF OF TEHUANTEPEC ALONG 95W/96W 
N OF 7N MOVING W 15 KT. THE NRN PART OF THE WAVE IS WELL-DEFINED 
WITH SCATTERED TSTMS OCCURRING OVER THE BAY OF CAMPECHE...BUT 
THE SIGNATURE IS RATHER WEAK OVER THE PACIFIC WATERS. SCATTERED 
MODERATE CONVECTION DOES LIE FROM THE GULF OF TEHUANTEPEC SWWD N 
OF 12N BETWEEN 94W-100W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N77W 6N90W 14N106W THEN 13N113W 
10N140W. SCATTERED MODERATE FROM 3N-7N BETWEEN 83W-88W. 
SCATTERED SHOWERS/TSTMS WITHIN 45 NM OF AXIS BETWEEN 88W-105W. 
SCATTERED SHOWERS/TSTMS WITHIN 60 NM OF AXIS BETWEEN 115W-129W. 
SCATTERED MODERATE FROM 6N-11N W OF 136W.

...DISCUSSION...

E OF 110W...
A STAGNANT UPPER LEVEL PATTERN PERSISTS ACROSS THE CENTRAL PART 
OF THE AMERICAS WITH AN UPPER HIGH CENTERED JUST W OF THE CAYMAN 
ISLANDS AND A SHARP UPPER TROUGH STILL POSITIONED ACROSS THE NW 
GULF INTO CENTRAL MEXICO. A SRN EXTENSION OF THE TROUGH ALSO 
STRETCHES FROM NEAR VERACRUZ MEXICO SWD 12N98W OVER THE PACIFIC. 
E OF THE TROUGH...FAIRLY STRONG E/NE FLOW IS BEING DRIVEN BY THE 
UPPER HIGH OVER THE W CARIBBEAN RESULTING IN SHEAR THAT IS TOO 
HIGH FOR ANY TROPICAL DEVELOPMENT. W OF THE TROUGH...T.S. DALILA 
IS PRODUCING ITS OWN UPPER LEVEL ANTICYCLONE WITH AN AXIS ALONG 
15N.

TSTMS ARE ONCE AGAIN DEVELOPING OVER THE SIERRA MADRE 
OCCIDENTALS OF MEXICO. THE SHARP UPPER TROUGH JUST N OF MEXICO 
CITY WILL TEND TO DRIVE THE TSTMS FROM MANZANILLO SWD TOWARDS 
THE SE...INCLUDING TSTMS JUST OFFSHORE ASSOCIATED WITH THE OUTER 
BANDS OF DALILA. N OF MANZANILLO...THE TSTMS ARE BEING DRIVEN TO 
THE SW BY AN EXTENDED RIDGE FROM THE NE PACIFIC WATERS INTO THE 
U.S. ROCKIES. SOME OF THESE TSTMS COULD APPROACH COASTAL AREAS 
OF THE E SHORE OF THE GULF OF CALIFORNIA DURING THE EVENING 
HOURS.

W OF 110W...
A LARGE UPPER HIGH IS CENTERED W OF BAJA CALIFORNIA NEAR 26N121W 
WITH A RIDGE AXIS EXTENDING SW TO 12N140W. WIDESPREAD DRY AIR 
AND LARGE-SCALE SUBSIDENCE LIE GENERALLY N OF 18N W OF 115W. S 
OF THE RIDGE...BROAD NE/E FLOW EXTENDS FROM T.S. DALILA AND THE 
SURROUNDING WATERS ALL THE WAY TO 140W. AS A RESULT...THE ITCZ W 
OF DALILA IS QUITE LINEAR AT THE MOMENT WITH VERY FEW ORGANIZED 
CONVECTIVE CLUSTERS.
 
$$
BERG