11 PM public advisory from NOA and 1 A.M Spaghetti models for Dorian.

Mindy D · ‎05-23-2010

000
WTNT35 KNHC 010252
TCPAT5

BULLETIN
Hurricane Dorian Advisory Number  31
NWS National Hurricane Center Miami FL       AL052019
1100 PM EDT Sat Aug 31 2019

...EXTREMELY DANGEROUS HURRICANE DORIAN MOVING CLOSER TO THE
NORTHWESTERN BAHAMAS...
...LIFE-THREATENING STORM SURGE...HURRICANE-FORCE WINDS...AND HEAVY
RAINFALL EXPECTED OVER THE NORTHWESTERNMOST BAHAMAS...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...26.3N 75.1W
ABOUT 125 MI...200 KM E OF GREAT ABACO ISLAND
ABOUT 310 MI...500 KM E OF WEST PALM BEACH FLORIDA
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...940 MB...27.76 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Northwestern Bahamas excluding Andros Island

A Hurricane Watch is in effect for...
* Andros Island

A Tropical Storm Watch is in effect for...
* Deerfield Beach to Sebastian Inlet

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life and
property should be rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in southern and central Florida should continue
to monitor the progress of Dorian.  Additional watches may be
required for portions of the east coast of Florida on Sunday.


For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM EDT (0300 UTC), the center of Hurricane Dorian was
located near latitude 26.3 North, longitude 75.1 West.  Dorian is
moving toward the west near 8 mph (13 km/h), and a slower westward
motion should continue for the next day or two, followed by
a gradual turn toward the northwest.  On this track, the core of
Dorian should be near or over portions of the northwestern Bahamas
on Sunday, and move closer to the Florida east coast late Monday
through Tuesday.

Data from NOAA and Air Force reconnaissance aircraft indicate that
the maximum sustained winds remain near 150 mph (240 km/h) with
higher gusts.  Dorian is a category 4 hurricane on the
Saffir-Simpson Hurricane Wind Scale.  Some fluctuations in intensity
are likely, but Dorian is expected to remain a powerful hurricane
during the next few days.

Hurricane-force winds extend outward up to 30 miles (45 km) from the
center and tropical-storm-force winds extend outward up to 105 miles
(165 km).

The latest minimum central pressure estimated from reconnaissance
aircraft data is 940 mb (27.76 inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Hurricane conditions are expected in the hurricane warning
area across the northwestern Bahamas by Sunday, with tropical storm
winds beginning overnight.

Tropical storm conditions are possible within the tropical storm
watch area on Monday.

STORM SURGE:  A life-threatening storm surge will raise water levels
by as much as 15 to 20 feet above normal tide levels in areas of
onshore winds on the Abaco Islands and Grand Bahama Island.  Near
the coast, the surge will be accompanied by large and destructive
waves.

RAINFALL:  Dorian is expected to produce the following rainfall
accumulations this weekend into the middle of next week:

Northwestern Bahamas...10 to 15 inches, isolated 25 inches.
Coastal sections of the southeast United States from central
Florida northward through the Carolinas...4 to 8 inches, isolated
12 inches.
Central Bahamas and South Florida...2 to 4 inches, isolated 6
inches.

This rainfall may cause life-threatening flash floods.

SURF:  Large swells will affect the east-facing shores of the
Bahamas, the Florida east coast, and the southeastern United States
coast during the next few days.  These swells are likely to cause
life-threatening surf and rip current conditions.  Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM EDT.
Next complete advisory at 500 AM EDT.

$$
Forecaster Brown

000
WTNT45 KNHC 010256
TCDAT5

Hurricane Dorian Discussion Number  31
NWS National Hurricane Center Miami FL       AL052019
1100 PM EDT Sat Aug 31 2019

Data from both Air Force and NOAA Hurricane Hunter aircraft indicate
that Dorian remains a very powerful hurricane, and the satellite
presentation is still quite impressive with a very stable,
well-defined eye.  There has been no evidence of concentric eyewalls
in aircraft or microwave data, which is somewhat surprising given
that the intensity has been at category 4 strength for 24 hours.
Both aircraft measured peak flight-level winds that support an
initial intensity of 130 kt.  There have been some higher surface
wind estimates from the SFMR, but these data are questionable based
on our experience of very high SFMR-measured wind speeds in recent
strong hurricanes that didn't match standard flight-level wind
reductions.

Dorian is forecast to continue moving over very warm waters and
into a low-shear environment during the next 12-24 hours, so some
additional strengthening is possible.  Difficult-to-predict
eyewall cycles, however, are likely to begin at some point within
the next day or so and could cause fluctuations in intensity.  After
72 hours, increasing southerly shear is likely to produce gradual
weakening, but Dorian is foreast to remain a dangerous hurricane
through the forecast period.

The hurricane is moving westward or 280/7 kt. A high pressure ridge
to the north of Dorian is predicted to remain intact into early
Sunday, and the hurricane should continue westward.  By late Sunday,
the dynamical models erode the western portion of the ridge, which
should cause the hurricane to slow down and become nearly stationary
over the northwestern Bahamas in 36 to 48 hours.  After that time,
the weakness in the ridge becomes more pronounced, and Dorian is
expected to turn northwestward, and eventually northeastward near
the southeastern United States coast.  Although there is general
agreement on this overall scenario, there is still considerable
spread on how close the storm will track to the east coast of
Florida and the southeastern coast of the United States.  The latest
HWRF run has shifted westward and takes Dorian across the coast of
central Florida.  The 18Z GFS also shifted a little left closer to
the Florida coast.  The latest multi-model consensus aids shifted
west closer to the previous NHC track, so very little change to
that forecast was made.  Although the exact NHC track forecast lies
east of the Florida peninsula, a track closer to the coast or even
a landfall remain a possibility.  Since the updated track was
slightly slower than the previous advisory, no additional watches
are needed for Florida at this time.

Key Messages:

1. A prolonged period of life-threatening storm surge, devastating
hurricane-force winds, and heavy rains capable of life-threatening
flash floods are expected on the Abaco Islands and Grand Bahama
Sunday through Monday, and a hurricane warning is in effect for
these areas.

2. A tropical storm watch is in effect for a portion of the Florida
east coast. Since Dorian is forecast to slow down and turn northward
as it approaches the coast, life-threatening storm surge and
dangerous hurricane-force winds are still possible along portions of
the Florida east coast by the early to middle part of next week.
Residents should have their hurricane plan in place, know if they
are in a hurricane evacuation zone, and listen to advice given by
local emergency officials.

3. There is an increasing risk of strong winds and dangerous storm
surge along the coasts of Georgia, South Carolina, and North
Carolina during the middle of next week. Residents in these areas
should continue to monitor the progress of Dorian.

4. Heavy rains, capable of life-threatening flash floods, are
possible over coastal sections of the southeastern United States
from Monday through Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 26.3N  75.1W  130 KT 150 MPH
 12H  01/1200Z 26.4N  76.3W  135 KT 155 MPH
 24H  02/0000Z 26.6N  77.4W  130 KT 150 MPH
 36H  02/1200Z 26.8N  78.1W  125 KT 145 MPH
 48H  03/0000Z 27.0N  78.5W  120 KT 140 MPH
 72H  04/0000Z 28.5N  79.3W  110 KT 125 MPH
 96H  05/0000Z 31.1N  80.0W   95 KT 110 MPH
120H  06/0000Z 34.0N  77.0W   85 KT 100 MPH

$$
Forecaster Brown