000
AXPZ20 KNHC 250315
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED JUL 25 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.

...SPECIAL FEATURE...

TROPICAL STORM DALILA CENTERED NEAR 18.2N 110.6W...OR ABOUT 40 
NM SSE OF SOCORRO ISLAND...AT 25/0300 UTC MOVING NNW AT 6 KT.  
MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT.  
ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. JUST BEFORE NIGHT 
FELL ON DALILA...A SPECIAL SHORTWAVE IR SATELLITE ENHANCEMENT 
REVEALED THAT THE LOW-LEVEL CENTER WAS ABOUT 40-50 NM N OF THE 
DEEPEST CONVECTION...A LITTLE FARTHER THAN FIRST THOUGHT. THERE 
IS STILL JUST ENOUGH NORTHEASTERLY SHEAR TO KEEP THE MOST 
SIGNIFICANT CONVECTIVE BANDING OVER THE SRN SEMICIRCLE AND OTHER 
SCATTERED SHOWERS/TSTMS FARTHER N AND NEAR THE MEXICAN COAST. 
SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 240 NM S 
SEMICIRCLE. SCATTERED SHOWERS/TSTMS ELSEWHERE FROM 15N-21N 
BETWEEN 100W-113W. SEE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS S OF COSTA RICA ALONG 83W 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 OAXACA MEXICO ALONG 96W/97W N OF 7N 
MOVING W 15 KT. MOST OF THE ACTIVE WEATHER ASSOCIATED WITH THE 
WAVE IS LOCATED N OF THE AREA WITH SCATTERED SHOWERS/TSTMS 
SPREADING NW ACROSS THE SW GULF OF MEXICO. THE DEEP CONVECTION 
OVER THE PACIFIC WATERS EARLIER IN THE DAY HAS MOSTLY DISSIPATED.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N77W 6N90W 14N106W THEN 13N113W 
10N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF LINE 
4N83W 7N95W. SCATTERED MODERATE WITHIN 60 NM OF AXIS BETWEEN 
113W-128W. SCATTERED MODERATE FROM 7N-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 E OF COZUMEL 
MEXICO 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 
16N.

TSTMS HAVE ONCE AGAIN DEVELOPED OVER THE SIERRA MADRE 
OCCIDENTALS OF MEXICO. THE SHARP UPPER TROUGH JUST N OF MEXICO 
CITY HAS TENDED TO DRIVE THE TSTMS S OF 20N TO THE SE WITH ONLY 
A FEW BRUSHING THE COAST NEAR ACAPULCO. SOME OF THE ACTIVITY OFF 
THE COAST IS ALSO IN ASSOCIATION WITH THE OUTER BANDS OF T.S. 
DALILA. N OF 20N...THE TSTMS HAVE BEEN DRIVEN SW AND NOW LINE 
THE E SHORE OF THE GULF OF CALIFORNIA BETWEEN PUERTO VALLARTA 
AND HERMOSILLO. 

W OF 110W...
A LARGE UPPER HIGH IS CENTERED W OF BAJA CALIFORNIA NEAR 27N124W 
WITH A RIDGE AXIS EXTENDING SW TO 13N140W. 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