Tropical Weather Outlook

NWS National Hurricane Center Miami FL

800 PM EDT Fri Jul 31 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Hurricane Isaias, located over the central Bahamas, and on newly developed Tropical Depression Ten, located over the far eastern Atlantic between Africa and the Cabo Verde Islands.

A westward-moving tropical wave located about 700 miles east of the Lesser Antilles continues to produce a few disorganized showers. Some slow development of this system is possible while it turns northwestward, and then northward over the western Atlantic through the middle of next week.

* Formation chance through 48 hours...low...near 0 percent.

* Formation chance through 5 days...low...30 percent.

$$

Forecaster Zelinsky

Hurricane Isaias Advisory Number  15
NWS National Hurricane Center Miami FL       AL092020
500 PM EDT Fri Jul 31 2020

...HURRICANE WARNING ISSUED FOR PORTIONS OF THE FLORIDA EAST COAST...
...TROPICAL STORM CONDITIONS AND HEAVY RAINS CONTINUE TO SPREAD ACROSS THE CENTRAL BAHAMAS...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...22.6N 75.7W
ABOUT 195 MI...320 KM SSE OF NASSAU
ABOUT 330 MI...535 KM SE OF FREEPORT GRAND BAHAMA ISLAND
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES

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

A Hurricane Warning is in effect for the east coast of Florida from Boca Raton to the Volusia/Brevard County Line.

A Hurricane Watch is in effect from the Volusia/Brevard County Line to the Flagler/Volusia County Line and from south of Boca Raton to Hallendale Beach.

A Storm Surge Watch is in effect for the east coast of Florida from Jupiter Inlet to Ponte Vedre Beach.

A Tropical Storm Watch is in effect from the Flagler/Volusia CountyLine to Ponte Vedre Beach.

A Tropical Storm Warning is in effect for Lake Okeechobee.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Boca Raton to the Volusia/Brevard County Line Florida
* Northwestern Bahamas
* Southeastern Bahamas
* Central Bahamas

A Hurricane Watch is in effect for...
* Hallendale Beach to south of Boca Raton Florida
* Volusia-Brevard County Line to the Flagler/Volusia County Line

A Storm Surge Watch is in effect for...
* Jupiter Inlet to Ponte Vedre Beach Florida

A Tropical Storm Warning is in effect for...
* Turks and Caicos Islands
* North of Ocean Reef to south of Boca Raton Florida
* Lake Okeechobee

A Tropical Storm Watch is in effect for...
* Flagler/Volusia County Line to Ponte Vedre Beach Florida

Interests elsewhere along the southeast coast of the United States should monitor the progress of Isaias.  Additional watches or warnings may be required later tonight and Saturday.

A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.  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 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. For a depiction of areas at risk, please see the National WeatherService Storm Surge Watch/Warning Graphic, available athurricanes.gov.

A Tropical Storm Warning means that tropical storm conditions are expected somewhere 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.

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 center of Hurricane Isaias was located
by satellite imagery and Bahamas radar data near latitude 22.6
North, longitude 75.7 West. Isaias is moving toward the northwest
near 15 mph (24 km/h), and a general northwestward motion with some
decrease in forward speed is expected for the next day or so,
followed by a turn toward the north-northwest by late Sunday.  On
the forecast track, the center of Isaias will continue to move near
or over the Southeastern Bahamas this afternoon and evening. Isaias
is forecast to be near the Central Bahamas tonight, and move near or
over the Northwestern Bahamas Saturday and near the east coast of
the Florida peninsula Saturday afternoon through Sunday.

Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts.  Strengthening is expected later tonight and early Saturday,
and Isaias is forecast to remain a hurricane for the next couple of
days.

Hurricane-force winds extend outward up to 35 miles (55 km) from the
center and tropical-storm-force winds extend outward up to 175 miles
(280 km).  A private weather observing station at Pitts Town Point,
Bahamas, recently reported a sustained wind of 37 mph (59 km/h).

The estimated minimum central pressure is 991 mb (29.27 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Isaias can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC, and
on the web at www.hurricanes.gov/text/MIATCDAT4.shtml.

STORM SURGE:  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...

Jupiter Inlet to Ponte Vedra Beach FL...2-4 ft
North Miami Beach to Jupiter Inlet FL...1-3 ft

The deepest water will occur along the immediate coast near and to
the right of the center, where the surge will be accompanied by
large waves.  Surge-related flooding depends on the relative timing
of the surge and the tidal cycle, 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.

A dangerous storm surge will raise water levels by as
much as 3 to 5 feet above normal tide levels in areas of onshore
winds in the Bahamas.

WIND:  Hurricane conditions will continue to spread northwestward
into the central and northwestern Bahamas tonight and Saturday.

Hurricane conditions are expected to reach the coast within the
hurricane warning area in Florida late Saturday and Saturday night.
Winds are expected to first reach tropical storm strength on  
Saturday, making outside preparations difficult or dangerous.  
Preparations to protect life and property should be rushed to
completion.

RAINFALL: Isaias is expected to produce the following rain
accumulations:

Bahamas, Turks and Caicos: 4 to 8 inches.

Cuba: 1 to 2 inches, with isolated maximum totals of 4 inches.

These rainfall amounts could lead to life-threatening flash  and
urban flooding, especially in low-lying and poorly drained areas.

From Friday night through Tuesday:

South Florida into east-Central Florida: 2 to 4 inches, with
isolated maximum totals of 6 inches.

Northeast Florida into coastal Georgia: 1 to 2 inches.

Carolinas into the mid Atlantic, including the southern and central
Appalachians: 2 to 4 inches, with isolated maximum totals of 6
inches.

Heavy rainfall from Isaias could result in isolated flash and urban
flooding, especially in low-lying and poorly drained areas. Isolated
minor river flooding is possible across the eastern Carolinas and
into Virginia.

SURF:  Swells generated by Isaias are affecting portions of
Hispaniola, eastern Cuba, the Turks and Caicos, and the southeastern
and central Bahamas. These swells will spread along the east coast
of Florida and the southeastern United States coast on Saturday.
These swells are likely to cause life-threatening surf and rip
current conditions. Please consult products from your local
weather office.

Probabilistic Storm Surge Graphics last updated Fri, 31 Jul 2020 21:53:55 GMT

3.15pm: From Long Island MP Adrian Gibson - "Per BPL, as of 2 p.m. today, power in Long Island has been shut off. BPL advises that Long Island - along with a few neighboring islands - will remain off until the storm passes or it is safe to re-energize."