Community Chat

[Mindy D]

000
WTNT45 KNHC 012056
TCDAT5

Hurricane Dorian Discussion Number  34
NWS National Hurricane Center Miami FL       AL052019
500 PM EDT Sun Sep 01 2019

The distinct eye of powerful Hurricane Dorian is moving over
Great Abaco.  The latest wind and pressure data from an Air Force
reconnaissance plane just before the eye hit the island indicated
that the winds reached 160 kt, which is the initial intensity for
this advisory. It is not very often that we measure such strong
winds. The minimum pressure measured by the plane was 910 mb.

The eye has been shrinking, and an eyewall replacement cycle is
possibly occurring.  The effect of the island terrain and the
eyewall replacement cycle should result in some slight fluctuations
in intensity during the next 24 to 36 hours, but the hurricane will
continue to be extremely dangerous one during that time. After 3
days, a more definite weakening trend should begin as the hurricane
encounters stronger shear. Dorian however, it is forecast to remain
a hurricane for the next 5 days.

Dorian has slowed down even more and is now moving toward the west
or 270 degrees at 4 kt. The steering currents are collapsing and
Dorian is expected to slow down a little more, prolonging its
catastrophic effects in the northwestern Bahamas. The NHC forecast
calls for a slow west to west-northwest motion during the next 48
hours. A turn to the north and northeast with a gradual increase in
forward speed is expected thereafter, as the mid-level trough over
the eastern United States deepens.  The current forecast is not very
different from the previous one, and it is very close to the
multi-model consensus TVCA. Both the deterministic and consensus
tracks have shown the usual variability to the right or to the left
from run to run, but the overall trend is for the hurricane to turn
northward offshore but dangerously close to the Florida peninsula.

Given the uncertainty in the track forecast and the anticipated
increase in size of the hurricane, a Hurricane Warning and Storm
Surge Warning have been issued for a portion of the Florida east
coast. It is once again emphasized that although the official track
forecast does not show landfall, users should not focus on the exact
track. A small deviation to the left of the track could bring the
intense core of the hurricane its dangerous winds closer to or onto
the Florida coast.

Key Messages:

1. A prolonged period of catastrophic winds and storm surge will
affect the Abaco Islands and Grand Bahama Island tonight. Everyone
there should take immediate shelter and not venture into the eye.

2. Life-threatening storm surge 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, 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 through late this week.

FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 26.6N  77.3W  160 KT 185 MPH
 12H  02/0600Z 26.7N  78.1W  155 KT 180 MPH
 24H  02/1800Z 26.8N  78.7W  145 KT 165 MPH
 36H  03/0600Z 27.0N  79.0W  135 KT 155 MPH
 48H  03/1800Z 27.7N  79.5W  125 KT 145 MPH
 72H  04/1800Z 30.0N  80.3W  105 KT 120 MPH
 96H  05/1800Z 33.0N  78.5W   90 KT 105 MPH
120H  06/1800Z 36.5N  73.5W   80 KT  90 MPH

$$
Forecaster Avila

000
WTNT35 KNHC 012123
TCPAT5

BULLETIN
Hurricane Dorian Advisory Number  34...Corrected
NWS National Hurricane Center Miami FL       AL052019
500 PM EDT Sun Sep 01 2019

Corrected to modify Storm Surge section

...EYE OF CATASTROPHIC HURRICANE DORIAN CRAWLING OVER THE ABACOS
ISLANDS IN THE BAHAMAS...
...DORIAN'S FURY NOW AIMING TOWARD GRAND BAHAMA...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...26.6N 77.3W
ABOUT 95 MI...150 KM E OF FREEPORT GRAND BAHAMA ISLAND
ABOUT 175 MI...280 KM E OF WEST PALM BEACH FLORIDA
MAXIMUM SUSTAINED WINDS...185 MPH...295 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...910 MB...26.88 INCHES


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

A Storm Surge Warning has been issued from Lantana to the
Volusia/Brevard County Line.

A Storm Surge Watch has been issued from the Volusia/Brevard County
Line to the Flagler/Volusia County Line.

A Hurricane Warning has been issued from Jupiter Inlet to the
Volusia/Brevard County Line.

A Hurricane Watch has been issued from the Volusia/Brevard County
Line to the Flagler/Volusia County Line

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Lantana to the Volusia/Brevard County Line

A Storm Surge Watch is in effect for...
* North of Deerfield Beach to Lantana
* Volusia/Brevard County Line to the Flagler/Volusia County Line

A Hurricane Warning is in effect for...
* Northwestern Bahamas excluding Andros Island
* Jupiter Inlet to the Volusia/Brevard County Line

A Hurricane Watch is in effect for...
* Andros Island
* North of Deerfield Beach to Jupiter Inlet
* Volusia/Brevard County Line to the Flagler/Volusia County Line

A Tropical Storm Warning is in effect for...
* North of Deerfield Beach to Jupiter Inlet

A Tropical Storm Watch is in effect for...
* North of Golden Beach to Deerfield Beach
* Lake Okeechobee

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.  This is a life-threatening situation.  Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions.  Promptly follow evacuation and other
instructions from local officials.

A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.

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 watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected within the warning area within 36 hours.

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

Interests elsewhere along the east coast of Florida should continue
to monitor the progress of Dorian, as additional watches or
warnings may be required later today.

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 500 PM EDT (2100 UTC), the distinct eye of Hurricane Dorian was
located near latitude 26.6 North, longitude 77.3 West. Dorian is
moving toward the west near 5 mph (7 km/h). A slower westward
to west-northwestward motions should continue for the next day or
two, followed by a gradual turn toward the northwest.  On this
track, the core of extremely dangerous Hurricane Dorian will
continue to pound Great Abaco this evening and move near or
over Grand Bahama Island tonight and Monday. The hurricane will
move dangerously close to the Florida east coast late Monday through
Tuesday night.

Maximum sustained winds are near 185 mph (295 km/h) with higher
gusts.  Dorian is a category 5 hurricane on the Saffir-Simpson
Hurricane Wind Scale.  Some fluctuations in intensity are likely,
and Dorian is expected to remain a catastrophic hurricane during the
next few days.

Hurricane-force winds extend outward up to 45 miles (75 km) from the
center and tropical-storm-force winds extend outward up to 140 miles
(220 km).

The last minimum central pressure measured by an Air Force
reconnaissance plane a couple of hours ago was 910 mb (26.88
inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Catastrophic hurricane conditions are occurring in the Abacos
Islands and will spread across Grand Bahama Island tonight. Do not
venture out into the eye, as winds will suddenly increase as the eye
passes.

Hurricane conditions are expected within the hurricane warning area
in Florida by late Monday or Tuesday.

Tropical storm conditions are expected within the tropical storm
warning area on Monday and Tuesday and are possible in the tropical
storm watch area by Monday night.

STORM SURGE:  A life-threatening storm surge will raise water levels
by as much as 18 to 23 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.

The combination of a dangerous storm surge and the tide will cause
normally dry areas near the coast to be flooded by rising waters
moving inland from the shoreline. The water could reach the
following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Flagler/Volusia County Line to Lantana FL...4 to 7 ft
North of Deerfield Beach to Lantana FL...2 to 4 ft

The surge will be accompanied by large and destructive waves.
Surge-related flooding depends on the how close the center of
Dorian comes to the Florida east coast, and can vary greatly over
short distances.  For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

RAINFALL:  Dorian is expected to produce the following rainfall
totals through late this week:

Northwestern Bahamas...12 to 24 inches, isolated 30 inches.
Coastal Carolinas...5 to 10 inches, isolated 15 inches.
The Atlantic Coast from the Florida peninsula through Georgia...3 to
6 inches, isolated 9 inches.
Southeastern Virginia...2 to 4 inches, isolated 6 inches.
Central Bahamas...2 to 4 inches, isolated 6 inches.

This rainfall may cause life-threatening flash floods.

SURF:  Large swells are already affecting east-facing shores of the
Bahamas, the Florida east coast, and will spread northward along 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 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Avila/Cangialosi