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TROPICAL STORM LANE DISCUSSION NUMBER 7
NATIONAL WEATHER SERVICE MIAMI FL
8 PM PDT WED SEP 06 2000
LANE IS DETERIORATING AS IT HAS BECOME ENTRAPPED IN AN ITCZ-LIKE
LARGE BAND OF LOW-LEVEL CYCLONIC FLOW AND CONVERGENCE THAT IS
PROVIDING COMPETITION AND LIMITING INFLOW. NO DOUBT THAT SOME
NORTHEASTERLY SHEAR HAS NOT BEEN HELPFUL EITHER...AS THE
CONVECTION NEAR THE CENTER HAS BECOME INCREASINGLY RAGGED. THE
INITIAL INTENSITY IS LOWERED TO 40 KT. ONE POSSIBLE SCENARIO NOW IS
FOR THE RELATIVELY SMALL TROPICAL CYCLONE TO LOSE ITS IDENTITY AND
DISSIPATE WITHIN THE ITCZ. ANOTHER POSSIBILITY IS THAT THE
CIRCULATION OF LANE WILL BE THE TRIGGER FOR THE CONSOLIDATION AND
DEVELOPMENT OF A LARGER CYCLONE. THE OFFICIAL FORECAST FAVORS THE
LATTER SCENARIO...CALLING FOR SOME ADDITIONAL WEAKENING OVER THE
NEXT 12 TO 24 HOURS BEFORE REDEVELOPMENT.
MOTION OVER THE PAST 12 HOURS HAS BEEN JUST EAST OF DUE SOUTH AT
ABOUT 5 KT. GUIDANCE SUGGESTS THAT LANE WILL SOON TURN BACK TO THE
NORTH AS A MID-LEVEL TROUGH TO THE EAST OF THE CYCLONE LIFTS AND
EASES THE SOUTHWARD STEERING. THE OFFICIAL FORECAST FOLLOWS THIS
LINE OF THINKING.
WIND RADII ON THE WEST SIDE HAVE BEEN SIGNIFICANTLY INCREASED AS THE
CIRCULATION OF LANE MERGES WITH THE LARGER SCALE FLOW.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 07/0300Z 13.4N 108.0W 40 KTS
12HR VT 07/1200Z 13.2N 107.8W 35 KTS
24HR VT 08/0000Z 13.3N 107.5W 35 KTS
36HR VT 08/1200Z 13.6N 107.0W 45 KTS
48HR VT 09/0000Z 14.5N 106.5W 55 KTS
72HR VT 10/0000Z 17.5N 107.0W 65 KTS
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