000
AXPZ20 KNHC 240916
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE JUL 24 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 
0900 UTC.

...SPECIAL FEATURE...

TROPICAL STORM DALILA CENTERED NEAR 16.7N 109.8W...OR ABOUT 185 
NM SSE OF SOCORRO ISLAND...AT 24/0900 UTC MOVING NNW AT 6 KT. 
MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. THE LARGE UPPER 
HIGH OVER THE BAJA PENINSULA AND UPPER TROUGH OVER THE GULF OF 
MEXICO CONTINUE TO PRODUCE 20 KT OF ENE SHEAR OVER DALILA YET 
THE SYSTEM IS STILL PRODUCING SIGNIFICANT CONVECTION ON ITS SW 
PERIPHERY. A LARGE BLOW-UP OF CONVECTION BEGAN JUST BEFORE 00 
UTC AND HAS BEEN MAINTAINED FOR THE PAST FEW HOURS EVEN WITH THE 
SHEAR SCALPING IT OFF TO THE SW. NUMEROUS STRONG CONVECTION IS 
WITHIN 180 NM SW QUADRANT...AND SCATTERED MODERATE IS ELSEWHERE 
FROM 12N-18N BETWEEN 110W-115W. SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS S OF GUATEMALA ALONG 92W N OF 5N MOVING W 
15 KT. EXCEPT FOR A BROAD CIRCULATION LYING ALONG THE ITCZ 
...THERE IS NO SIGNIFICANT REFLECTION OF THE WAVE OVER THE 
PACIFIC WATERS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG THE LINE...7N77W 7N90W 14N105W THEN 
13N110W 12N128W 8N135W 8N140W.
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 NM OF THE 
POINT 12.1N88.6W. SCATTERED MODERATE TO STRONG CONVECTION IS 
WITHIN 120 NM OF 12.8N104.9W.

...DISCUSSION...

MEXICO...
A DEEP UPPER LEVEL TROUGH OVER THE GULF OF MEXICO...WITH ITS 
AXIS STRETCHING W ACROSS MEXICO FROM NEAR MEXICO CITY TO THE 
GULF OF CALIFORNIA...CONTINUES TO PRODUCE STRONG NORTHERLY FLOW 
OVER MUCH OF THE COUNTRY WEST OF 97W. TSTM ACTIVITY DURING THE 
DAY AND EVENING HAS DIMINISHED TONIGHT.

E OF 110W...
THE SHARP AND DEEP MID TO UPPER LEVEL TROUGH EXTENDING SW ACROSS 
THE GULF OF MEXICO HAS SOMEWHAT BRIDGED THE ISTHMUS OF 
TEHUANTEPEC AND MERGED WITH AN INVERTED TROUGH LOCATED S OF 
MEXICO ALONG 100W. THE TROUGH IS EMBEDDED IN THE DEEP EASTERLIES 
AND IS MOVING W AT ABOUT 10 KT. AN UPPER RIDGE EXTENDING FROM A 
HIGH NEAR THE CAYMAN ISLANDS SW ACROSS GUATEMALA TO 12N98W IS 
PRODUCING WEAK DIFFLUENCE WHERE THE FLOW DIVERGES FROM THE 
EASTERLIES...AND THIS IS HELPING TO PRODUCE SCATTERED TSTMS OVER 
SRN MEXICO...GUATEMALA...BELIZE AND EL SALVADOR.  

W OF 110W...
A LONG UPPER LEVEL RIDGE AXIS EXTENDS FROM FAR NW MEXICO SW TO 
NEAR 20N135W...SEPARATING DEEP TROPICAL MOISTURE TO ITS SE FROM 
STRONG SUBSIDENCE NEAR IT AND TO ITS NW. THE FLOW TO ITS SE IS 
PRIMARILY EASTERLY AND IS RESPONSIBLE FOR PRODUCING THE STRONG 
SHEAR OVER T.S. DALILA. THIS FLOW IS ALSO ADVECTING MUCH OF THE 
MOISTURE OVER THE ERN PARTS WWD TO ABOUT 130W. HOWEVER... 
LOW-LEVEL CONVERGENCE ALONG THE ITCZ IS STRONGEST E OF 120W AND 
THAT IS WHERE MOST OF THE DEEP CONVECTION LIES. A SHARP UPPER 
TROUGH AND ASSOCIATED FRONTAL BOUNDARY HAVE STALLED JUST NW OF 
THE REGION WITH THE SUBTROPICAL RIDGE SUPPRESSED...KEEPING THE 
EASTERLY TRADES LARGELY BELOW 20 KT.
 
$$
LL