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IRMA NOW A CAT 4

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WTNT31 KNHC 042036

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BULLETIN

Hurricane Irma Advisory Number  22

NWS National Hurricane Center Miami FL       AL112017

500 PM AST Mon Sep 04 2017

…IRMA STRENGTHENS AS IT HEADS TOWARD THE LEEWARD ISLANDS…

…PREPARATIONS WITHIN THE WARNING AREA SHOULD BE RUSHED TO

COMPLETION…

SUMMARY OF 500 PM AST…2100 UTC…INFORMATION

———————————————-

LOCATION…16.7N 54.4W

ABOUT 490 MI…790 KM E OF THE LEEWARD ISLANDS

MAXIMUM SUSTAINED WINDS…130 MPH…215 KM/H

PRESENT MOVEMENT…W OR 265 DEGREES AT 13 MPH…20 KM/H

MINIMUM CENTRAL PRESSURE…944 MB…27.88 INCHES

WATCHES AND WARNINGS

——————–

CHANGES WITH THIS ADVISORY:

The government of France has issued a Tropical Storm Warning for

Guadeloupe.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for…

* Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, and Nevis

* Saba, St. Eustatius, and Sint Maarten

* Saint Martin and Saint Barthelemy

A Hurricane Watch is in effect for…

* Guadeloupe

* British Virgin Islands

* U.S. Virgin Islands

* Puerto Rico, Vieques, and Culebra

A Tropical Storm Warning is in effect for…

* Guadeloupe

A Tropical Storm Watch is in effect for…

* Dominica

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 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.

Interests in the Dominican Republic, Haiti, the Turks and Caicos

Islands, and the southeastern Bahamas 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 PM AST (2100 UTC), the center of Hurricane Irma was located

near latitude 16.7 North, longitude 54.4 West.  Irma is moving

toward the west near 13 mph (20 km/h) and this general motion is

expected to continue into Tuesday, followed by a turn toward the

west-northwestward late Tuesday.  On the forecast track, the center

of Irma will move near or over portions of the northern Leeward

Islands Tuesday night and early Wednesday.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate

that the maximum sustained winds have increased to near 130 mph

(215 km/h) with higher gusts.  Irma is a category 4 hurricane on the

Saffir-Simpson Hurricane Wind Scale.  Additional strengthening is

forecast during the next 48 hours.

Hurricane-force winds extend outward up to 40 miles (65 km) from the

center and tropical-storm-force winds extend outward up to 140 miles

(220 km).

The latest minimum central pressure reported by reconnaissance

aircraft is 944 mb (27.88 inches).

HAZARDS AFFECTING LAND

———————-

STORM SURGE:  The combination of a dangerous storm surge and large

breaking waves will raise water levels by as much as 6 to 9 feet

above normal tide levels along the coasts of the extreme northern

Leeward Islands 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.

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…

British and U.S. Virgin Islands except St. Croix…4 to 6 ft

Northern coast of Puerto Rico…2 to 4 ft

Southern coast of Puerto Rico and St. Croix…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.

WIND:  Hurricane conditions are expected within the hurricane

warning area by Tuesday night, with tropical storm conditions

expected by late Tuesday.  Hurricane conditions are possible within

the hurricane watch area in the Virgin Islands and Puerto Rico by

late Wednesday, with tropical storm conditions possible by early

Wednesday.  Tropical Storm conditions are expected within the

tropical storm warning area by late Tuesday.

RAINFALL:  Irma is expected to produce total rainfall accumulations

of 3 to 6 inches across the Leeward Islands, with isolated maximum

amounts of 10 inches across the northern Leeward Islands.  These

rainfall amounts may cause life-threatening flash floods and

mudslides.

SURF:  Swells generated by Irma will affect the northern Leeward

Islands during the next several 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 AST.

Next complete advisory at 1100 PM AST.

$$

Forecaster Brown

Gov. Rick Scott has declared a state of emergency for all 67 counties in preparation for Hurricane Irma.