Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane MARIA


Hurricane Maria Discussion Number  31
NWS National Hurricane Center Miami FL       AL152017
500 PM EDT Sat Sep 23 2017

Maria's eye became cloud filled again today, although convective
cloud tops have been cooling within the eyewall during the past
couple of hours.  A NOAA Hurricane Hunter plane conducting a
research mission has not yet sampled the entire circulation, but
they did report that the central pressure had fallen by a couple of
millibars.  In addition, a Coyote unmanned aerial vehicle launched
by the plane has been measuring winds of 120-125 kt at altitudes
of 1200-1300 ft, which supports maximum surface winds of 100 kt.

The initial motion remains north-northwestward, or 345/8 kt, but
Maria is expected to turn northward by this evening or overnight
while moving between a mid-level high near Bermuda and a cut-off low
over the northeastern Gulf coast.  A blocking ridge sliding eastward
over the northeastern U.S. should cause Maria to slow down to a
forward motion of 5 kt or less beginning in about 36 hours, lasting
through the end of the forecast period.  The track models appear to
have stabilized for the moment, with this being the first cycle in
about a day where they have not shown a significant westward shift.
Therefore, the updated NHC track forecast is relatively unchanged
from the previous forecast during the first 3 days.  The day 4 point
was shifted a little closer to the North Carolina coast to be closer
to the consensus aids and the Florida State Superensemble, and all
the models indicate that a northeastward motion away from the coast
should begin by day 5.

Vertical shear will remain relatively low over Maria for the next
several days, and the hurricane will be moving over warm waters at
least for the next 3 days.  However, the depth of the thermocline
does become more shallow, with oceanic heat content values steadily
decreasing over the next 36 hours.  With Maria expected to slow
down, upwelling of colder water becomes a greater factor, and that
could modulate the hurricane's intensity during the next several
days.  Maria also could still move over Jose's cold wake in 4-5
days, which would likely cause additional weakening.  The NHC
intensity forecast remains just above the intensity consensus,
however it should be noted that the normally skillful HCCA model is
toward the lower end of the guidance suite.  It therefore wouldn't
be surprising if Maria weakened more than shown in the official


1. Maria's forecast track has shifted closer to the U.S. east coast,
and it is becoming increasingly likely that some direct impacts will
occur along portions of the coast next week.  Interests along the
coast of the Carolinas and the Mid-Atlantic should monitor the
progress of Maria, as tropical storm or hurricane watches may be
needed for part of this area on Sunday.

2. Swells from Maria are increasing along the coast of the
southeastern United States and are expected to reach the
Mid-Atlantic coast tonight and on Sunday.  These swells will likely
cause dangerous surf and rip currents at the beach through much of
next week.  For more information, please monitor information from
your local National Weather Service office at


INIT  23/2100Z 26.3N  72.5W  100 KT 115 MPH
 12H  24/0600Z 27.6N  72.8W  100 KT 115 MPH
 24H  24/1800Z 29.1N  73.1W  100 KT 115 MPH
 36H  25/0600Z 30.1N  73.3W   95 KT 110 MPH
 48H  25/1800Z 31.1N  73.3W   90 KT 105 MPH
 72H  26/1800Z 32.9N  73.3W   80 KT  90 MPH
 96H  27/1800Z 34.5N  73.5W   70 KT  80 MPH
120H  28/1800Z 35.0N  72.0W   65 KT  75 MPH

Forecaster Berg