000
WTNT45 KNHC 192046
TCDAT5

Hurricane Maria Discussion Number  15
NWS National Hurricane Center Miami FL       AL152017
500 PM AST Tue Sep 19 2017

Maria has continued to strengthen this afternoon, with surface and
flight-level winds from an Air Force Reserve Hurricane Hunter
aircraft supporting an intensity of 145 kt, and the central
pressure inside the 5 n mi wide eye falling to 916 mb.  The
aircraft data also indicates that an outer wind maximum is present
about 20-30 n mi from the center, but this has not yet developed
into enough of an outer eyewall to stop the intensification in the
inner eyewall.

The initial motion remains 300/9.  The forecast track philosophy
remains the same, with the eye of Maria expected to move near the
U. S. Virgin Islands tonight and across Puerto Rico on Wednesday,
followed by a motion just north of the eastern Dominican Republic
Wednesday night and Thursday.  Subsequently, a break in the
subtropical ridge caused in part by Hurricane Jose should allow
Maria to turn north-northwestward and northward by the end of the
forecast period.  Only minor changes have occurred in the track
guidance since the last advisory, and the new track has only minor
adjustments from the previous track.

Some additional strengthening is possible this evening before the
outer eyewall becomes better defined or the cyclone reaches its
maximum potential intensity. It now appears likely that Maria will
be at category 5 intensity when it moves over the U. S. Virgin
Islands and Puerto Rico, although there is a chance that the start
of the eyewall replacement cycle might reduce the intensity a little
bit.  The hurricane should weaken as it crosses Puerto Rico, and
after that proximity to Hispaniola and less favorable upper-level
winds are likely to lead to continued slow weakening.  The new
intensity forecast remains at the upper edge of the intensity
guidance.


KEY MESSAGES:

1. Maria's core is expected to move near or over St. Croix and
Puerto Rico tonight and Wednesday, bringing life-threatening wind,
storm surge, and rainfall impacts to portions of those islands.
Everyone in these areas should follow advice from local officials to
avoid life-threatening flooding from storm surge and rainfall.

2. Wind speeds atop and on the windward sides of hills and mountains
and on high-rise buildings could be much stronger than the
near-surface winds indicated in this advisory.

3. A hurricane warning also in effect for the remainder of the
Virgin Islands and the northern coast of the Dominican Republic,
where Maria is expected to bring dangerous wind, storm surge, and
heavy rainfall.

4. A hurricane watch is in effect for the southeastern Bahamas and
the Turks and Caicos, where Maria could bring hurricane conditions
on Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  19/2100Z 16.8N  64.0W  145 KT 165 MPH
 12H  20/0600Z 17.5N  65.2W  145 KT 165 MPH
 24H  20/1800Z 18.4N  66.7W  130 KT 150 MPH...OVER PUERTO RICO
 36H  21/0600Z 19.3N  68.1W  125 KT 145 MPH...OVER WATER
 48H  21/1800Z 20.2N  69.4W  120 KT 140 MPH
 72H  22/1800Z 22.5N  71.0W  115 KT 130 MPH
 96H  23/1800Z 25.5N  72.0W  110 KT 125 MPH
120H  24/1800Z 28.5N  72.5W   95 KT 110 MPH

$$
Forecaster Beven