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Tropical Storm Michael Discussion Number  22
NWS National Hurricane Center Miami FL       AL142018
1100 PM EDT Thu Oct 11 2018

Michael has just about lost its tropical characteristics.  The
low-level circulation is becoming increasingly elongated as it
becomes embedded within a frontal zone, and the center is becoming
ill defined.  The center we have been tracking across North
Carolina appears to have moved into extreme southeastern Virginia,
although it should be noted that a second low center, one with even
lower pressure, has formed farther north along the western shore of
Chesapeake Bay, closer to the deepest convection.  Needless to say,
Michael has just about become post-tropical, and that
transformation should be complete overnight.  The estimated maximum
winds remain 45 kt based on recent observations from coastal North
Carolina.  Due to baroclinic forcing, some re-intensification of
the post-tropical low is expected during the next 24-36 hours,
following guidance from the Ocean Prediction Center.  The
post-tropical low should then begin to weaken again in 2-3 days and
will likely be absorbed by another weather system to the west of
Europe by day 4.

The initial motion based on the continuity-following low center is
northeastward, or 055/22 kt.  Michael is embedded within the
mid-latitude flow and is therefore expected to accelerate toward
the east-northeast over the western and northern Atlantic during the
next couple of days, even approaching speeds of about 50 kt in 48
hours.  The track guidance remains tightly clustered, and no
significant changes to the official track forecast were required.
Michael's center is expected to move off the coast of Virginia
within the next couple of hours, with tropical-storm- and
gale-force winds moving away from the coast during the day on
Friday.

Gale- to storm-force winds are expected over portions of the
Mid-Atlantic coast as Michael exits the U.S. east coast and becomes
post-tropical. Non-tropical high wind watches, warnings, and
advisories have been issued by local NWS offices for wind hazards in
these areas north of Duck, North Carolina.

Key Messages:

1. Life-threatening flash flooding is occurring over portions of
the southern Mid-Atlantic states and will continue overnight.

2. Strong, possibly damaging winds are expected over portions of
extreme eastern North Carolina, southeastern Virginia, and the
southern Delmarva peninsula overnight.  These winds have the
potential to cause tree and structural damage, plus power outages.

3. Dangerous storm surge is possible overnight along the sound side
of the North Carolina Outer Banks from Ocracoke Inlet to Duck, where
a Storm Surge Watch is in effect.


FORECAST POSITIONS AND MAX WINDS

INIT  12/0300Z 37.1N  76.1W   45 KT  50 MPH
 12H  12/1200Z 39.2N  71.2W   50 KT  60 MPH...POST-TROP/EXTRATROP
 24H  13/0000Z 42.5N  61.5W   60 KT  70 MPH...POST-TROP/EXTRATROP
 36H  13/1200Z 45.4N  49.0W   60 KT  70 MPH...POST-TROP/EXTRATROP
 48H  14/0000Z 47.1N  34.8W   55 KT  65 MPH...POST-TROP/EXTRATROP
 72H  15/0000Z 47.6N  14.6W   45 KT  50 MPH...POST-TROP/EXTRATROP
 96H  16/0000Z...DISSIPATED

$$
Forecaster Berg

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