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Tropical Depression Claudette Discussion Number   9
NWS National Hurricane Center Miami FL       AL032021
400 PM CDT Sat Jun 19 2021
 
Claudette continues to move inland with its center now located
over southwestern Alabama.  Surface observations indicate that the
system has weakened, and based on that information the initial
intensity is lowered to 30 kt.  This makes Claudette a tropical
depression.  The cyclone is still producing gusty winds and bands
of heavy rain across portions of Mississippi, Alabama, Georgia, and
the Florida Panhandle.
 
As expected, the tropical depression has turned to the northeast
and accelerated some, with the latest initial motion estimated to
be 040/14 kt.  A turn to the east-northeast is expected
tonight and Sunday as Claudette moves in the westerlies on the
north side of the subtropical ridge.  This motion should take the
system across portions of the southeast U.S. during the next couple
of days and then over the western Atlantic and toward Atlantic
Canada early next week.  The models remain in relatively good
agreement, and the NHC track forecast lies near the middle of the
guidance envelope.  This forecast is very similar to the previous
one, except again a little to the right at the longer range forecast
times.
 
Some additional weakening seems likely during the next day or so
while Claudette moves across the southeast U.S.  However, most of
the models show the system regaining some strength when it moves
across the Carolinas and over the western Atlantic waters Sunday
night and Monday.  This predicted strengthening is likely due in
part to baroclinic processes. The 12Z ECMWF is weaker than previous
runs, and overall the remainder of the intensity guidance is largely
unchanged from the previous cyclone.  Based on the latest models,
the NHC intensity forecast is just an update of previous one and
lies near the HCCA and IVCN consensus aids. Once the system moves
north of the Gulf Stream Current in a few days, it is forecast to
transition to an extratropical cyclone prior to reaching Atlantic
Canada.
 
Key Messages:
 
1. Claudette is expected to produce heavy rainfall and flash
flooding across portions of the Florida Panhandle, eastern Alabama,
and Georgia through tonight, and into the Carolinas on Sunday.
Considerable flash, urban, and small stream flooding impacts are
expected across these areas.
 
2. Tropical storm conditions are possible along portions of the
North Carolina coast Sunday night and Monday, where a Tropical Storm
Watch is in effect.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  19/2100Z 32.2N  87.9W   30 KT  35 MPH...INLAND
 12H  20/0600Z 32.9N  86.0W   25 KT  30 MPH...INLAND
 24H  20/1800Z 33.7N  82.7W   25 KT  30 MPH...INLAND
 36H  21/0600Z 34.6N  78.5W   35 KT  40 MPH...INLAND
 48H  21/1800Z 36.4N  73.8W   40 KT  45 MPH...OVER WATER
 60H  22/0600Z 39.1N  68.8W   40 KT  45 MPH
 72H  22/1800Z 42.3N  63.4W   40 KT  45 MPH...POST-TROP/EXTRATROP
 96H  23/1800Z 51.0N  52.4W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  24/1800Z...DISSIPATED
 
$$
Forecaster Cangialosi
 
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