HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM ARLENE DISCUSSION NUMBER  15
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT TUE JUN 15 1999

THE LOW LEVEL CENTER OF ARLENE IS DIFFICULT TO LOCATE IN IR IMAGERY.
THE BEST ESTIMATE OF THE POSITION IS A LITTLE SOUTH OF THE PREVIOUS
ESTIMATES. SOME FURTHER RE-LOCATION MAY BE NECESSARY WHEN VISIBLE
IMAGERY AND RECONNAISSANCE REPORTS ARRIVE.

THE INITIAL MOTION IS ESTIMATED AT 285/04...A LITTLE TO THE LEFT OF
THE PREVIOUS PACKAGE. MODEL GUIDANCE CONTINUES TO INDICATE A GRADUAL
TURN TO THE NORTHWEST AND NORTH...WITH CONTINUED DISAGREEMENT AS
TO WHETHER ARLENE WILL PASS EAST OR WEST OF BERMUDA. THE OFFICIAL
FORECAST IS SHIFTED TO THE LEFT OF THE PREVIOUS PACKAGE AND TAKES
THE CENTER OVER BERMUDA. IT SHOULD BE NOTED THAT THE 00Z GFDL IS
MUCH FASTER TURNING ARLENE NORTHWARD THAN THE 18Z RUN AND THUS LOOKS
A LITTLE SUSPECT. 
 
EVEN WITH THE DIFFICULTY IN LOCATING THE CENTER...IT REMAINS EXPOSED
WEST OF THE DEEP CONVECTION. THE SHEAR HAS LESSENED TO THE POINT
WHERE ANTICYCLONIC OUTFLOW HAS DEVELOPED OVER THE DEEP CONVECTION. 
HOWEVER...THERE IS STILL ENOUGH SHEAR TO HAMPER INTENSIFICATION.
THE INTENSITY FORECAST CONTINUES TO CALL FOR SLIGHT STRENGTHENING
ALTHOUGH IT IS NOT INCLUDED IN THE OFFICIAL FORECAST...THERE IS A
POSSIBILITY THAT ARLENE MAY MEET STRONG SHEAR BEYOND 48 HOURS AND
WEAKEN.
 
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS ENROUTE AND
IS SCHEDULED TO REACH ARLENE AROUND 11Z. 

A TROPICAL STORM WATCH REMAINS IN EFFECT FOR BERMUDA. THE AIRCRAFT
DATA SHOULD HELP DETERMINE THE EXTENT OF TROPICAL STORM FORCE WINDS
AROUND THE CENTER...AND THUS WHEN WARNINGS MAY BE REQUIRED.

BEVEN/GUINEY
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     15/0900Z 29.7N  61.7W    40 KTS
12HR VT     15/1800Z 29.9N  62.4W    40 KTS
24HR VT     16/0600Z 30.4N  63.3W    45 KTS
36HR VT     16/1800Z 31.4N  64.3W    45 KTS
48HR VT     17/0600Z 33.0N  65.0W    45 KTS
72HR VT     18/0600Z 36.0N  65.5W    45 KTS
 
NNNN