Hurricane Dorian Forecast Discussion Number 30

Hurricane Dorian Storm Track
Issued at 500 PM EDT Sat Aug 31 2019
000
WTNT45 KNHC 020852
TCDAT5

Hurricane Dorian Discussion Number  36
NWS National Hurricane Center Miami FL       AL052019
500 AM EDT Mon Sep 02 2019

Satellite imagery continues to show that Dorian has an extremely
well-defined eye embedded within very cold cloud tops.  The
diameter of the eye appears to have expanded to near 20 n mi, and
radar data, especially from the Bahamas Department of Meteorology
radar, show that there are concentric eyewalls. The hurricane also
continues to exhibit strong upper-tropospheric outflow.  The initial
intensity estimate has been reduced to 145 kt, which lies between
earlier Hurricane Hunter estimates and satellite intensity estimates
from TAFB and SAB.  This lowering of intensity is consistent with
the development of a concentric eyewall. During the next few days,
Dorian should be encountering some increase in shear, which will
likely result in weakening.  However it is anticipated that the
system will remain a dangerous major hurricane for the next several
days.  The official intensity forecast lies between the
statistical-dynamical guidance and the corrected multi-model
consensus.

Steering currents have weakened, and Dorian has almost come to a
standstill over eastern Grand Bahama Island, with an initial motion
of 270/1 kt.  The mid-tropospheric high to the north of the
hurricane that had been steering Dorian westward has collapsed.
Global models indicate that, in a couple of days, a weakness in the
ridge will develop along 75W-80W.  This would likely cause Dorian to
move northwestward to northward toward and through this weakness.
Later in the forecast period, the system is expected to accelerate
northeastward on the southern side of a broad mid-tropospheric
trough. The official track forecast is very close to the previous
one and to the corrected dynamical model consensus, HCCA.  Although
the official forecast does not show Dorian making landfall along the
Florida east coast, it is still possible for the hurricane to
deviate from this forecast, and move very near or over the coast.
Users are reminded not to focus on the exact forecast track.


Key Messages:

1. A prolonged period of catastrophic winds and storm surge will
continue to affect Grand Bahama Island through today and tonight.
Everyone there should remain in shelter and not venture into the
eye.

2. Life-threatening storm surges and dangerous hurricane-force winds
are expected along portions of the Florida east coast through
mid-week, and storm surge and hurricane warnings are in effect. Only
a slight deviation to the left of the official forecast would bring
the core of Dorian near or over the Florida east coast.  Residents
should listen to advice given by local emergency officials.

3. There is an increasing likelihood of strong winds and dangerous
storm surge along the coasts of Georgia, South Carolina, and North
Carolina later this week.  Residents in these areas should continue
to monitor the progress of Dorian and listen to advice given by
local emergency officials.

4. Heavy rains, capable of producing life-threatening flash floods,
are expected over northern portions of the Bahamas and coastal
sections of the Southeast and lower Mid-Atlantic regions of the
United States into Friday.


FORECAST POSITIONS AND MAX WINDS

INIT  02/0900Z 26.6N  78.2W  145 KT 165 MPH
 12H  02/1800Z 26.7N  78.7W  140 KT 160 MPH
 24H  03/0600Z 26.9N  79.0W  130 KT 150 MPH
 36H  03/1800Z 27.6N  79.5W  120 KT 140 MPH
 48H  04/0600Z 28.7N  80.0W  110 KT 125 MPH
 72H  05/0600Z 31.3N  79.8W  100 KT 115 MPH
 96H  06/0600Z 34.5N  76.5W   85 KT 100 MPH
120H  07/0600Z 38.5N  70.0W   75 KT  85 MPH

$$
Forecaster Pasch

Official content courtesy of the National Hurricane Center, NOAA.gov