Issued at 1100 AM AST FRI SEP 13 2013
000
WTNT42 KNHC 131440
TCDAT2
TROPICAL DEPRESSION GABRIELLE DISCUSSION NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072013
1100 AM AST FRI SEP 13 2013
AMBIGUITIES FROM AN 0200 UTC ASCAT PASS SUGGEST THAT THERE ARE VERY
LITTLE...IF ANY...NORTHERLY WINDS ON THE WEST SIDE OF THE
CIRCULATION. GABRIELLE HAS ACCELERATED TOWARD THE NORTH-NORTHEAST
SINCE THAT TIME...REDUCING THE LIKELIHOOD THAT NORTH WINDS ARE
PRESENT. HOWEVER...A LARGE BURST OF CONVECTION DURING THE PAST 6
HOURS AT LEAST MAKES IT PLAUSIBLE THAT THE CIRCULATION REMAINS
CLOSED...AND SO GABRIELLE IS BEING HELD AS A 30 KT TROPICAL
DEPRESSION FOR THIS ADVISORY. A SLIGHT INCREASE IN THE MAXIMUM
WINDS IS POSSIBLE TODAY DUE TO BAROCLINIC PROCESSES.
THE FORWARD SPEED OF GABRIELLE HAS INCREASED DURING THE PAST FEW
HOURS...AND THE INITIAL MOTION ESTIMATE IS NOW 020/20. ALL OF THE
DYNAMICAL MODELS SUGGEST THAT THE DEPRESSION WILL CONTINUE TO
ACCELERATE TOWARD THE NORTH-NORTHEAST WHILE IT INTERACTS WITH A
DEEP-LAYER TROUGH LOCATED OVER THE EASTERN UNITED STATES
AND CANADA. THE GUIDANCE SUGGESTS THAT GABRIELLE WILL OPEN UP INTO
A TROUGH LATER TODAY...ALTHOUGH THE OFFICIAL FORECAST
CONSERVATIVELY SHOWS A 12-HOUR FORECAST POINT. AFTER
THAT...GABRIELLE OR ITS REMNANTS SHOULD GET ABSORBED BY AN
APPROACHING COLD FRONT.
FORECAST POSITIONS AND MAX WINDS
INIT 13/1500Z 39.1N 66.5W 30 KT 35 MPH
12H 14/0000Z 43.2N 64.6W 35 KT 40 MPH...POST-TROPICAL
24H 14/1200Z...DISSIPATED
$$
FORECASTER FRANKLIN/ZELINSKY
Continue reading...
000
WTNT42 KNHC 131440
TCDAT2
TROPICAL DEPRESSION GABRIELLE DISCUSSION NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072013
1100 AM AST FRI SEP 13 2013
AMBIGUITIES FROM AN 0200 UTC ASCAT PASS SUGGEST THAT THERE ARE VERY
LITTLE...IF ANY...NORTHERLY WINDS ON THE WEST SIDE OF THE
CIRCULATION. GABRIELLE HAS ACCELERATED TOWARD THE NORTH-NORTHEAST
SINCE THAT TIME...REDUCING THE LIKELIHOOD THAT NORTH WINDS ARE
PRESENT. HOWEVER...A LARGE BURST OF CONVECTION DURING THE PAST 6
HOURS AT LEAST MAKES IT PLAUSIBLE THAT THE CIRCULATION REMAINS
CLOSED...AND SO GABRIELLE IS BEING HELD AS A 30 KT TROPICAL
DEPRESSION FOR THIS ADVISORY. A SLIGHT INCREASE IN THE MAXIMUM
WINDS IS POSSIBLE TODAY DUE TO BAROCLINIC PROCESSES.
THE FORWARD SPEED OF GABRIELLE HAS INCREASED DURING THE PAST FEW
HOURS...AND THE INITIAL MOTION ESTIMATE IS NOW 020/20. ALL OF THE
DYNAMICAL MODELS SUGGEST THAT THE DEPRESSION WILL CONTINUE TO
ACCELERATE TOWARD THE NORTH-NORTHEAST WHILE IT INTERACTS WITH A
DEEP-LAYER TROUGH LOCATED OVER THE EASTERN UNITED STATES
AND CANADA. THE GUIDANCE SUGGESTS THAT GABRIELLE WILL OPEN UP INTO
A TROUGH LATER TODAY...ALTHOUGH THE OFFICIAL FORECAST
CONSERVATIVELY SHOWS A 12-HOUR FORECAST POINT. AFTER
THAT...GABRIELLE OR ITS REMNANTS SHOULD GET ABSORBED BY AN
APPROACHING COLD FRONT.
FORECAST POSITIONS AND MAX WINDS
INIT 13/1500Z 39.1N 66.5W 30 KT 35 MPH
12H 14/0000Z 43.2N 64.6W 35 KT 40 MPH...POST-TROPICAL
24H 14/1200Z...DISSIPATED
$$
FORECASTER FRANKLIN/ZELINSKY
Continue reading...