BULLETIN
Hurricane Irma Advisory Number 45
NWS National Hurricane Center Miami FL AL112017
500 AM EDT Sun Sep 10 2017
…EYE OF IRMA ABOUT TO MOVE ACROSS THE LOWER FLORIDA KEYS…
SUMMARY OF 500 AM EDT…0900 UTC…INFORMATION
———————————————-
LOCATION…24.1N 81.5W
ABOUT 40 MI…65 KM SSE OF KEY WEST FLORIDA
ABOUT 140 MI…225 KM S OF NAPLES FLORIDA
MAXIMUM SUSTAINED WINDS…130 MPH…215 KM/H
PRESENT MOVEMENT…NW OR 325 DEGREES AT 8 MPH…13 KM/H
MINIMUM CENTRAL PRESSURE…928 MB…27.41 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:
The Government of the Bahamas has replaced the Hurricane Warning
for the Northwestern Bahamas with a Tropical Storm Watch for the
Northwestern Bahamas islands of Bimini and Grand Bahama.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for…
* South Santee River southward to Jupiter Inlet
* North Miami Beach southward around the Florida peninsula to the
Ochlockonee River
* Florida Keys
* Tampa Bay
A Hurricane Warning is in effect for…
* Fernandina Beach southward around the Florida peninsula to Indian
Pass
* Florida Keys
* Lake Okeechobee
* Florida Bay
* Cuban provinces of Ciego de Avila, Sancti Spiritus, Villa Clara,
Matanzas, and La Habana
A Hurricane Watch is in effect for…
* North of Fernandina Beach to Edisto Beach
A Tropical Storm Warning is in effect for…
* West of Indian Pass to the Okaloosa/Walton County Line
* North of Fernandina Beach to South Santee River
A Tropical Storm Watch is in effect for…
* Bimini and Grand Bahama
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 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 somewhere within the warning area.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests elsewhere in Cuba and the southeastern United States
should monitor the progress of Irma.
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
the United States, please monitor products issued by your national
meteorological service.
DISCUSSION AND 48-HOUR OUTLOOK
——————————
At 500 AM EDT (0900 UTC), the center of Hurricane Irma was located
near latitude 24.1 North, longitude 81.5 West. Irma is moving toward
the northwest near 8 mph (13 km/h). A turn toward the north-
northwest and an increase in forward speed are expected later today,
with that motion continuing through Monday. On the forecast track,
the eye of Irma should move over the Lower Florida Keys in the next
few hours, then move near or over the southwestern coast of the
Florida Peninsula later today through tonight. Irma should then
move inland over the Florida panhandle and southwestern Georgia
Monday afternoon.
Maximum sustained winds are near 130 mph (215 km/h) with higher
gusts. Irma is a category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale. While weakening is forecast, Irma is
expected to remain a powerful hurricane as it moves through the
Florida Keys and and near the west coast of Florida.
Hurricane-force winds extend outward up to 80 miles (130 km) from
the center and tropical-storm-force winds extend outward up to 220
miles (350 km). The National Ocean Service station at Vaca Key
Florida recently reported sustained winds of 48 mph (78 km/h) and a
gust of 78 mph (126 km/h). A private anemometer at Alligator Reef
Light, Florida recently reported a wind gust of 88 mph (141 km/h).
The latest minimum central pressure reported by an Air Force
Reserve Hurricane Hunter aircraft is 928 mb (27.41 inches).
HAZARDS AFFECTING LAND
———————-
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 is
expected to reach the following HEIGHTS ABOVE GROUND if the peak
surge occurs at the time of high tide…
Cape Sable to Captiva…10 to 15 ft
Captiva to Ana Maria Island…6 to 10 ft
Card Sound Bridge through Cape Sable, including the Florida Keys…
5 to 10 ft
Ana Maria Island to Clearwater Beach, including Tampa Bay…
5 to 8 ft
North Miami Beach to Card Sound Bridge, including Biscayne Bay…
3 to 5 ft
South Santee River to Fernandina Beach…4 to 6 ft
Clearwater Beach to Ochlockonee River…4 to 6 ft
Fernandina Beach to Jupiter Inlet…2 to 4 ft
North of North Miami Beach to Jupiter Inlet…1 to 2 ft
The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
destructive 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.
The combination of a life-threatening storm surge and large breaking
waves will raise water levels ABOVE NORMAL TIDE LEVELS by the
following amounts within the hurricane warning area near and to the
north of the center of Irma. Near the coast, the surge will be
accompanied by large and destructive waves.
Northern coast of Cuba in the warning area…5 to 10 ft
WIND: Hurricane conditions are expected to continue within the
hurricane warning area along the north coast of Cuba through
this morning. Hurricane conditions are spreading across portions of
the Florida Keys, and should spread northward over the remainder of
the Keys and the southern Florida peninsula during the next several
hours. Tropical storm and hurricane conditions are expected to
spread northward across the remainder of the warning areas through
Monday. Tropical storm conditions are possible in the watch area in
the Northwestern Bahamas today.
RAINFALL: Irma is expected to produce the following rain
accumulations through Wednesday:
Western Cuba…Additional 3 to 6 inches, isolated 10 inches.
Western Bahamas…Additional 2 to 4 inches, isolated 6 inches.
The Florida Keys…15 to 20 inches, isolated 25 inches.
The southern Florida peninsula…10 to 15 inches, isolated 20
inches.
The remainder of the Florida peninsula and southeast Georgia…8 to
12 inches, isolated 16 inches.
The rest of Georgia, eastern Florida Panhandle, southern and western
South Carolina, and western North Carolina…3 to 6 inches, isolated
10 inches.
Eastern Alabama and southern Tennessee…2 to 5 inches.
In all areas this rainfall may cause life-threatening flash floods
and, in some areas, mudslides.
TORNADOES: Tornadoes are possible through tonight, mainly across
southern, central, and eastern portions of the Florida Peninsula.
THE EYE: Do not venture outside when the calm eye of the hurricane
passes over, as dangerous winds will return very quickly when the
eye moves away.
SURF: Swells generated by Irma are affecting the southeast coast of
the United States. 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 AM EDT.
Next complete advisory at 1100 AM EDT.
$$
Forecaster Beven
