000
WTNT45 KNHC 270836
TCDAT5

Tropical Storm Maria Discussion Number  45
NWS National Hurricane Center Miami FL       AL152017
500 AM EDT Wed Sep 27 2017

Maria has changed little in structure since the last advisory.  A
band of deep convection attempted to wrap around the western side
of the circulation, but that has since dissipated due to continued
shear and dry air.  The initial intensity remains 60 kt based on
surface winds measured by the SFMR on the previous reconnaissance
flight.  Maria will likely be moving over some warm and cold eddies
associated with the Gulf Stream during the next 2 to 3 days, and
with vertical shear expected to gradually decrease during that
time, only slow weakening is anticipated.  After day 3, vertical
shear increases significantly, and Maria is expected to complete
extratropical transition by day 4.  The global models then indicate
that the low will be absorbed by a larger extratropical low over
the northeastern Atlantic by day 5.

Earlier reconnaissance fixes indicated that Maria's center was
jumping around a bit, but its average motion is estimated to be
slowly northward, or 005 degrees at 4 kt.  Maria is moving around
the western periphery of a mid-level ridge located over the central
Atlantic, and it should enter the mid-latitude westerlies in about
36 hours, at which point it is expected to accelerate northeastward
across the north Atlantic.  Most of the model spread continues to
be in the along-track direction, highlighted by the faster GFS and
HWRF models and the slower ECMWF model.  As was the case before,
the updated NHC track forecast splits the difference between these
scenarios and remains close to the multi-model consensus aids.


KEY MESSAGES:

1. Maria is forecast to slowly move away from the U.S. east coast
during the next day or so.  However, tropical storm conditions are
expected to continue along portions of the North Carolina coast
through much of today.

2. Storm surge flooding, especially along the sound side of the
North Carolina Outer Banks, is expected, and a storm surge warning
and watch are in effect for portions of eastern North Carolina.

3. Swells generated by Maria are affecting much of the east coast of
the United States, Atlantic Canada, Bermuda, the Bahamas, and the
Turks and Caicos Islands.  These swells are likely to cause
life-threatening surf and rip current conditions.  Please consult
products from your local weather office for more information.


FORECAST POSITIONS AND MAX WINDS

INIT  27/0900Z 35.1N  72.9W   60 KT  70 MPH
 12H  27/1800Z 35.7N  72.7W   55 KT  65 MPH
 24H  28/0600Z 36.2N  71.7W   55 KT  65 MPH
 36H  28/1800Z 36.5N  69.3W   50 KT  60 MPH
 48H  29/0600Z 37.0N  65.3W   50 KT  60 MPH
 72H  30/0600Z 40.5N  52.5W   50 KT  60 MPH
 96H  01/0600Z 47.5N  32.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  02/0600Z...ABSORBED BY A LARGER EXTRATROPICAL LOW

$$
Forecaster Berg