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Tropical Storm Maria Discussion Number  43
NWS National Hurricane Center Miami FL       AL152017
500 PM EDT Tue Sep 26 2017

There has been little change to Maria's cloud pattern since the
previous advisory.  The center of the large circulation is located
near the northwestern edge of the deep convection due to
west-northwesterly shear and dry air intrusion.  Reconnaissance
aircraft have not found any SFMR winds higher than 60 kt for quite
some time, so the initial intensity has been reduced to that value.
Cool waters and moderate shear should cause some additional
decrease in wind speed over the next day or so, but little
change in strength is forecast later in the period as Maria
accelerates east-northeastward over the north Atlantic.  Maria
should complete extratropical transition in about 96 hours, and
could merge with a large extratropical low in about 5 days.

Maria is continuing its slow northward motion around the
western side of a subtropical ridge.  The mid-latitude westerlies
are forecast to dip southward as a large trough moves across eastern
North America later this week.  This should cause Maria to turn
east-northeastward by Thursday, and then accelerate ahead of the
trough by late in the week.  The track guidance has trended slightly
slower and the NHC forecast has been adjusted accordingly.  The new
official forecast is near the middle of the tightly clustered
guidance.


KEY MESSAGES:

1. Maria is forecast to continue moving northward, paralleling the
U.S. east coast for the next 36 hours, and will likely bring some
direct impacts to portions of the North Carolina coast through
Wednesday where a tropical storm warning is in effect.

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.  These swells are also affecting Bermuda, the
Turks and Caicos Islands, and the Bahamas.  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  26/2100Z 34.1N  73.0W   60 KT  70 MPH
 12H  27/0600Z 34.8N  73.0W   60 KT  70 MPH
 24H  27/1800Z 35.5N  72.7W   55 KT  65 MPH
 36H  28/0600Z 36.0N  71.9W   55 KT  65 MPH
 48H  28/1800Z 36.3N  69.9W   55 KT  65 MPH
 72H  29/1800Z 38.3N  60.6W   55 KT  65 MPH
 96H  30/1800Z 44.0N  44.5W   50 KT  60 MPH...POST-TROP/EXTRATROP
120H  01/1800Z 51.5N  25.0W   45 KT  50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brown

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