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TROPICAL STORM MITCH DISCUSSION NUMBER  37
NATIONAL WEATHER SERVICE MIAMI FL
4 PM EST FRI OCT 30 1998
 
THE INITIAL MOTION ESTIMATE IS 240/03.  THE 12Z AVIATION MODEL SHOWS
THE HIGH IN THE GULF OF MEXICO BEING ERODED BY A SHORT WAVE TROUGH
IN THE NEXT 3 DAYS.  THIS IS THE BASIS FOR A SLOW NORTHWARD
COMPONENT OF MOTION SHOWN BY THE GFDL...NOGAPS...AND AVIATION
MODELS.  THE UKMET SHOWS MORE OF A NORTHWESTWARD MOTION.  THE
OFFICAL TRACK FORECAST IS SIMILAR TO...AND AN UPDATE OF...THE
PREVIOUS ADVISORY.
 
THE CONVECTION IN THE MAIN BANDING FEATURE HAS BEEN DECREASING.
HOWEVER A RECENT REPORT OF 49 KNOTS FROM ROATAN REQUIRES THAT THE
WIND SPEED BE INCREASED BACK UP TO 50 KNOTS.  THIS DOES NOT MEAN
THAT A STRENGTENING TREND IS OCCURRING...BUT IT MEANS THAT OUR
PREVIOUS ESTIMATES WERE TOO LOW??  AN EVEN HIGHER OBSERVATION OF
70 KNOTS FROM PUERTO BARRIOS IS BELIEVED TO BE A RESULT OF A
FUNNELING EFFECT FROM NEARBY MOUNTAINS.  EXCEPT FOR THIS ADJUSTMENT
OF WIND SPEED...MITCH IS EXPECTED TO CONTINUE WEAKENING AS MOST OF
THE CIRCULATION IS FORECAST TO REMAIN OVER LAND.
 
HEAVY RAINFALL OVER HONDURAS...NICARAGUA...GUATEMALA...BELIZE...AND
PORTIONS OF THE YUCATAN PENINSULA CONTINUES TO BE THE PRIMARY
THREAT FROM MITCH.  WESTERN NICARAGUA...IN PARTICULAR...IS CURRENTLY
UNDER A CLOUD SYSTEM WITH VERY DEEP AND PERSISTENT CONVECTION.
 
LAWRENCE
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     30/2100Z 15.1N  86.8W    50 KTS...INLAND
12HR VT     31/0600Z 15.1N  87.6W    40 KTS...INLAND
24HR VT     31/1800Z 15.4N  88.6W    30 KTS...INLAND
36HR VT     01/0600Z 16.1N  89.4W    30 KTS...INLAND
48HR VT     01/1800Z 17.1N  90.0W    30 KTS...INLAND
72HR VT     02/1800Z 19.0N  90.5W    30 KTS...INLAND
 
 
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