000
WTPZ44 KNHC 040832
TCDEP4
 
TROPICAL STORM DALILA DISCUSSION NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042013
200 AM PDT THU JUL 04 2013

DALILA CONTINUES TO GRADUALLY WEAKEN DUE TO ONGOING MODERATE
EASTERLY VERTICAL WIND SHEAR AND DRY AIR ENTRAINMENT...WITH THE
CENTER NOW ON THE EASTERN EDGE OF THE REMAINING CONVECTION.  BASED
MAINLY ON CONTINUITY FROM THE PREVIOUS ADVISORY...THE INITIAL
INTENSITY IS REDUCED TO AN UNCERTAIN 45 KT.

THE INITIAL MOTION IS NOW 265/4.  A LOW/MID-LEVEL RIDGE TO THE NORTH
OF THE CYCLONE SHOULD STEER DALILA GENERALLY WESTWARD FOR THE NEXT
SEVERAL DAYS...AND THE NEW FORECAST TRACK FOLLOWS THIS SCENARIO
VERY CLOSE TO THE PREVIOUS FORECAST.  SOME OF THE GLOBAL MODELS
SUGGEST AN ALTERNATIVE SCENARIO...THAT DALILA OR ITS REMNANTS COULD
INTERACT WITH THE TROPICAL DISTURBANCE APPROACHING FROM THE
SOUTHEAST.  SHOULD THIS INTERACTION OCCUR...DALILA COULD MOVE MORE
TOWARD THE SOUTHWEST THAN CURRENTLY FORECAST.
 
THE CURRENT SHEAR AND DRY AIR ENTRAINMENT SHOULD CONTINUE THROUGH
THE FORECAST PERIOD...CAUSING DALILA TO STEADILY WEAKEN.  IN
ADDITION...THE CYCLONE IS FORECAST TO MOVE OVER COLDER SEA SURFACE
TEMPERATURES AFTER 48 HOURS.  THE NEW INTENSITY FORECAST CALLS FOR
DALILA TO WEAKEN TO A TROPICAL DEPRESSION IN ABOUT 36 HOURS...AND
TO DEGENERATE TO A REMNANT LOW IN ABOUT 72 HOURS.  IT IS POSSIBLE
THAT BOTH OF THESE EVENTS COULD OCCUR EARLIER THAN FORECAST.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/0900Z 17.5N 108.9W   45 KT  50 MPH
 12H  04/1800Z 17.4N 109.8W   40 KT  45 MPH
 24H  05/0600Z 17.4N 110.9W   35 KT  40 MPH
 36H  05/1800Z 17.5N 111.9W   30 KT  35 MPH
 48H  06/0600Z 17.9N 113.1W   30 KT  35 MPH
 72H  07/0600Z 18.5N 115.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  08/0600Z 19.0N 118.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  09/0600Z 19.0N 122.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BEVEN