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Hurricane Maria Discussion Number  40
NWS National Hurricane Center Miami FL       AL152017
1100 PM EDT Mon Sep 25 2017

Maria's deep convection continues to slowly diminish, especially
over the western semicircle of the circulation, where only a few
cold tops are seen.  The Air Force Hurricane Hunters reported an
SFMR-observed surface wind of 67 kt over the northeast quadrant, so
the current intensity is maintained at 70 kt for the time being.
Although vertical shear is not forecast by the dynamical guidance to
increase significantly over the next few days, cooler waters and
drier air are likely to cause Maria to weaken to a tropical storm by
late Tuesday or Wednesday.  By the end of the forecast period,
global models indicate that the system will have transformed into a
frontal cyclone over the northern Atlantic, and this is also
reflected in the official forecast.

Maria continues to move northward quite slowly, or 360/6 kt, on the
western side of a subtropical high pressure area.  A mid-level ridge
over the northeastern United States should continue to retard the
system's forward progress for another day or two.  Afterward, this
ridge is predicted to weaken, and Maria should begin to accelerate
northeastward to east-northeastward away from the United States east
coast, ahead of a broad mid-tropospheric trough.  The official track
forecast is very similar to the previous one and is in line with the
multi-model consensus.  This is also between the faster GFS and
slower ECMWF tracks.

KEY MESSAGES:

1. Maria is forecast to continue moving northward, paralleling the
U.S. east coast, and it is likely that some direct impacts will
occur along portions of the North Carolina coast beginning Tuesday,
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 beginning on Tuesday, and a
Storm Surge Watch has been issued for portions of eastern North
Carolina.

3. Swells generated by Maria are affecting much of the
east coast of the United States from Florida through southern New
England.  These swells are also affecting Bermuda, Puerto Rico, the
northern coast of Hispaniola, 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  26/0300Z 32.3N  73.1W   70 KT  80 MPH
 12H  26/1200Z 33.2N  73.2W   65 KT  75 MPH
 24H  27/0000Z 34.1N  73.2W   65 KT  75 MPH
 36H  27/1200Z 35.0N  73.0W   60 KT  70 MPH
 48H  28/0000Z 35.5N  72.4W   60 KT  70 MPH
 72H  29/0000Z 36.5N  68.4W   60 KT  70 MPH
 96H  30/0000Z 40.0N  57.5W   60 KT  70 MPH
120H  01/0000Z 47.0N  40.0W   60 KT  70 MPH...POST-TROP/EXTRATROP

$$
Forecaster Pasch

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