000
AXPZ20 KNHC 271617
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JUL 27 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION DALILA AT 22.9N 117.2W MOVING W-NW AT 9 KT. 
MAXIMUM SUSTAINED WIND SPEED 25 GUSTS TO 35 KT.  ESTIMATED 
MINIMUM CENTRAL PRESSURE 1006 MB.  SEE LATEST NHC FORECAST/ 
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE 
DETAILS.  WITH AN IMMINENT DEMISE QUICKLY APPROACHING...THE LAST 
ADVISORY ON DALILA WAS ISSUED AT 1500 UTC.  ALL DEEP CONVECTION 
HAS DISAPPEARED AND REGENERATION HIGHLY UNLIKELY.  A REMNANT LOW 
PRES WILL BE HANDLED IN EAST PACIFIC HIGH SEAS FORECAST...FZPN03.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 105W N OF 3N MOVING W 15 KT APPROACHING AN 
UPPER ENVIRONMENT MORE FAVORABLE FOR DEVELOPMENT.  GLOBAL MODELS
SUGGEST CIRCULATION WITHIN 24-36 HRS WITH IMPROVED ORGANIZATION 
THEREAFTER.  THIS SOLUTION IS ACCEPTED AS SCATTERED TSTMS WITHIN 
180 NM E OF WAVE AXIS ARE PRESENTLY INCREASING IN COVERAGE. 

...ITCZ...
ITCZ AXIS ALONG 9N84W  11N103W  17N115W  10N132W  12N140W.  
SCATTERED MODERATE CONVECTION WITHIN 90 NM OF AXIS E OF 90W.  
ISOLATED MODERATE CONVECTION WITHIN 45 NM OF AXIS FROM 90W-101W.

...DISCUSSION...
UPPER LEVEL CYCLONIC VORTEX STILL UNABLE TO BREAK INTO E PAC 
BASIN DUE TO WELL ANCHORED RIDGE FROM 32N125W TO ANTICYCLONIC 
CIRCULATION AT 15N140W.  WITH THE EXCEPTION OF DALILA MOISTURE 
DEBRIS...AIR MASS IN ENTIRE REGION W OF 115W REMAINS DRY UNDER 
STRONG RIDGE SUBSIDENCE.   

UPPER LEVEL RIDGE ANCHORED OVER CENTRAL MEXICO BRINGS THE ONLY 
SWATH OF MOISTURE INTO E PAC ON ITS SRN PERIPHERY COMBINED WITH 
CYCLONIC VORTEX OVER WRN CARIBBEAN.  ABUNDANT MOISTURE CROSSES 
YUCATAN AND CENTRAL AMERICA BUT ONLY A TROPICAL WAVE ALONG 105W 
IS CAPABLE OF UPLIFT MECHANICS TO PRODUCE CONVECTION...DISCUSSED 
ABOVE. 

AT THE SURFACE...
WITH THE DEMISE OF DALILA...THE TROPICAL WAVE AT 105W BECOMES 
THE MAIN FEATURE IN TODAYS DISCUSSION.  GLOBAL MODELS SPIN 
SOUTHERN TIP OF WAVE INTO ROTATION AS UPPER ENVIRONMENT BECOMES 
MORE FAVORABLE FOR DEVELOPMENT.  THIS CAUSES SOUTHERN PERIPHERY 
TO  INCREASE WIND AND SEAS AND TRAIL CIRCULATION W ALONG 10N.  
OTHERWISE E PAC REMAINS TAME.   

$$
WALLY BARNES