ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM

Hurricane Maria Discussion Number  14
NWS National Hurricane Center Miami FL       AL152017
1100 AM AST Tue Sep 19 2017

Reports from an Air Force Reserve Hurricane Hunter Aircraft indicate
that Maria regained category 5 status shortly after the last
advisory, and that it is currently maintaining an intensity near 140
kt with a central pressure near 927 mb.  The aircraft data suggests
an outer wind maximum that could be the start of an eyewall
replacement cycle, but this feature does not yet have a good
signature in radar data or microwave imagery.

The eye of Maria has been wobbling quite a bit, but a smoother
long-term motion is 300/9.  There is little change to the track
forecast reasoning or the forecast track since the previous
advisory.  A weak ridge situated over the western Atlantic is
expected to steer Maria west-northwestward through 48 hours, and on
this track the center of the hurricane is forecast to pass near or
over the Virgin Islands and Puerto Rico on Wednesday.  After that
time, the western portion of the ridge is forecast to weaken,
partially due to the influence of the large circulation of Hurricane
Jose off the U.S. east coast.  This pattern should cause Maria to
turn northwestward and then north-northwestward by days 4-5.  The
track guidance is tightly clustered through 72 h and fairly well
clustered at 120 h, and the new track is to the left of center of
the cluster mainly between the GFS and ECMWF models.

Maria should remain in a generally favorable environment through 48
h, and based on this and the latest guidance the new intensity
forecast keeps Maria at 135-140 kt up to the time of landfall in
Puerto Rico.  After crossing Puerto Rico, the upper-level winds are
expected to become less favorable, and the intensity forecast shows
a slow weakening that follows the upper edge of the guidance.  A
complication to the intensity forecast is that there will likely be
fluctuations caused by eyewall replacement cycles superimposed on
top of the general trends shown in the official forecast.

KEY MESSAGES:

1. Maria will continue to affect portions of the Leeward Islands
today and the core of the hurricane is expected to move near or over
Puerto Rico and the Virgin Islands tonight and Wednesday. 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.

FORECAST POSITIONS AND MAX WINDS

INIT  19/1500Z 16.3N  63.1W  140 KT 160 MPH
 12H  20/0000Z 17.0N  64.1W  140 KT 160 MPH
 24H  20/1200Z 18.0N  65.7W  135 KT 155 MPH
 36H  21/0000Z 18.8N  67.1W  125 KT 145 MPH
 48H  21/1200Z 19.6N  68.4W  125 KT 145 MPH
 72H  22/1200Z 21.5N  70.5W  120 KT 140 MPH
 96H  23/1200Z 24.5N  72.0W  105 KT 120 MPH
120H  24/1200Z 27.5N  72.5W   95 KT 110 MPH

$$
Forecaster Beven

NNNN