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Hurricane Maria Discussion Number  42
NWS National Hurricane Center Miami FL       AL152017
1100 AM EDT Tue Sep 26 2017

The satellite presentation of Maria has continued to slowly degrade
over the past 24 hours, as deep convection is now confined to the
southeastern portion of the circulation.  Peak surface wind
estimates from the Stepped Frequency Microwave Radiometer on the
reconnaissance aircraft have been around 60 kt both overnight and
this morning, but due to sampling considerations for such a large
wind field the initial wind speed is held at 65 kt for this
advisory.  Cool waters and moderate west-northwesterly shear are
expected to cause a gradual decrease in intensity over the next
couple of days, and Maria is forecast to weaken to a tropical storm
later today or tonight.  Little change in strength is expected later
in the period while Maria accelerates east-northeastward and begins
to interact with a frontal boundary over the north Atlantic.

Maria continues to move slowly northward around the western side of
a subtropical ridge.  A mid- to upper-level ridge over the
northeastern United States to the north of Maria is likely to
keep the cyclone's forward motion slow for the next 24-36 h.  After
that time, a mid-latitude trough moving across the Great Lakes
region is expected to lift Maria east-northeastward or northeastward
at an increasing forward speed.  The track guidance remains in good
agreement on the scenario but there continue to be large speed
differences after 48 hours.  The new official forecast is a little
slower than the previous one at days 3-5 to be more in line with the
various consensus aids.


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  26/1500Z 33.6N  73.1W   65 KT  75 MPH
 12H  27/0000Z 34.3N  73.1W   60 KT  70 MPH
 24H  27/1200Z 35.1N  73.0W   60 KT  70 MPH
 36H  28/0000Z 35.7N  72.4W   55 KT  65 MPH
 48H  28/1200Z 36.1N  70.9W   55 KT  65 MPH
 72H  29/1200Z 37.6N  63.6W   55 KT  65 MPH
 96H  30/1200Z 42.5N  49.5W   55 KT  65 MPH
120H  01/1200Z 50.5N  30.0W   50 KT  60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brown

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