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HURRICANE DARBY DISCUSSION NUMBER   8
NATIONAL WEATHER SERVICE MIAMI FL
8 PM PDT FRI JUL 24 1998

DARBY HAS INTENSIFIED RAPIDLY DURING THE PAST FEW HOURS AND MAXIMUM
WINDS ARE 100 KNOTS.  THIS ESTIMATE IS BASED ON SUBJECTIVE T-NUMBERS
FROM SAB...TAFB AND RAW NUMBERS OBTAINED FROM THE NEW OBJECTIVE
DVORAK TECHNIQUE (ODT). THESE RAW NUMBERS HAVE BEEN OSCILLATING
AROUND 5.0 AND 6.0.  THE CLOUD PATTERN IS EXCELLENT AND CONSISTS OF
A DISTINCT EYE EMBEDDED WITHIN A CDO...WELL DEFINED CURVED BANDS AND
OUTFLOW IN ALL QUADRANTS. DARBY HAS AT LEAST 24 MORE HOURS OVER WARM
WATERS...SO ADDITIONAL STRENGTHENING IS POSSIBLE.  THEREAFTER... THE
HURRICANE IS FORECAST TO CROSS THE 25 DEGREE ISOTHERM AND WEAKENING
SHOULD BEGIN.  THE OFFICIAL FORECAST WEAKENS THE HURRICANE IN
AGREEMENT WITH SHIPS MODEL BUT SLOWER THAN SHIFOR AND MUCH SLOWER
THAN THE GFDL.  THE GFDL WEAKENS DARBY TO A 50-KNOT STORM IN ABOUT
36 HOURS. 
 
DARBY...LIKE MOST OF THE EASTERN PACIFIC HURRICANES IS MOVING AT
290/10.  SINCE THE RIDGE TO THE NORTH IS NOT EXPECTED TO CHANGE
...THIS MOTION SHOULD CONTINUE THROUGH 72 HOURS. THIS IS CONSISTENT
WITH GUIDANCE.        

AVILA
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     25/0300Z 15.0N 118.6W   100 KTS
12HR VT     25/1200Z 15.5N 120.1W   110 KTS
24HR VT     26/0000Z 16.0N 122.0W   120 KTS
36HR VT     26/1200Z 17.0N 124.5W   110 KTS
48HR VT     27/0000Z 18.0N 127.0W   100 KTS
72HR VT     28/0000Z 19.5N 132.5W    75 KTS
 
 
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