Hurricane Irma

Forecast Advisory 18

---

444
WTNT21 KNHC 032050
TCMAT1

HURRICANE IRMA FORECAST/ADVISORY NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112017
2100 UTC SUN SEP 03 2017

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE GOVERNMENT OF ANTIGUA HAS ISSUED A HURRICANE WATCH FOR THE
ISLANDS OF ANTIGUA... BARBUDA... ANGUILLA... MONTSERRAT... ST.
KITTS... AND NEVIS.

THE GOVERNMENT OF THE NETHERLANDS HAS ISSUED A HURRICANE WATCH FOR
THE ISLANDS OF SABA... ST. EUSTATIUS... AND SINT MAARTEN.

THE GOVERNMENT OF FRANCE HAS ISSUED A HURRICANE WATCH FOR ST.
MARTIN AND SAINT BARTHELEMY.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WATCH IS IN EFFECT FOR...
* ANTIGUA... BARBUDA... ANGUILLA... MONTSERRAT... ST. KITTS... AND
NEVIS
* SABA... ST. EUSTATIUS... AND SINT MAARTEN
* SAINT MARTIN AND SAINT BARTHELEMY

INTERESTS IN THE REMAINDER OF THE LEEWARD ISLANDS... THE BRITISH AND
U.S. VIRGIN ISLANDS... AND PUERTO RICO SHOULD MONITOR THE PROGRESS
OF IRMA. ADDITIONAL HURRICANE AND TROPICAL STORM WATCHES MAY BE
REQUIRED FOR PORTIONS OF THIS AREA ON MONDAY.

HURRICANE CENTER LOCATED NEAR 17.6N 49.8W AT 03/2100Z
POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE WEST OR 260 DEGREES AT 12 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 969 MB
EYE DIAMETER 10 NM
MAX SUSTAINED WINDS 100 KT WITH GUSTS TO 120 KT.
64 KT....... 30NE 20SE 15SW 30NW.
50 KT....... 60NE 40SE 30SW 50NW.
34 KT.......120NE 80SE 50SW 120NW.
12 FT SEAS..390NE 150SE 150SW 390NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 17.6N 49.8W AT 03/2100Z
AT 03/1800Z CENTER WAS LOCATED NEAR 17.8N 49.2W

FORECAST VALID 04/0600Z 17.2N 51.4W
MAX WIND 105 KT...GUSTS 130 KT.
64 KT... 30NE 20SE 15SW 30NW.
50 KT... 60NE 40SE 30SW 50NW.
34 KT...120NE 80SE 50SW 120NW.

FORECAST VALID 04/1800Z 16.8N 53.5W
MAX WIND 110 KT...GUSTS 135 KT.
64 KT... 30NE 20SE 20SW 30NW.
50 KT... 60NE 40SE 30SW 60NW.
34 KT...130NE 90SE 60SW 130NW.

FORECAST VALID 05/0600Z 16.8N 55.8W
MAX WIND 115 KT...GUSTS 140 KT.
64 KT... 30NE 25SE 20SW 30NW.
50 KT... 70NE 50SE 40SW 70NW.
34 KT...140NE 100SE 70SW 140NW.

FORECAST VALID 05/1800Z 17.3N 58.2W
MAX WIND 120 KT...GUSTS 145 KT.
50 KT... 70NE 50SE 40SW 70NW.
34 KT...150NE 120SE 80SW 140NW.

FORECAST VALID 06/1800Z 19.1N 63.5W
MAX WIND 120 KT...GUSTS 145 KT.
50 KT... 80NE 60SE 50SW 70NW.
34 KT...180NE 160SE 90SW 160NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY

OUTLOOK VALID 07/1800Z 21.2N 68.8W
MAX WIND 115 KT...GUSTS 140 KT.

OUTLOOK VALID 08/1800Z 23.0N 73.5W
MAX WIND 115 KT...GUSTS 140 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.6N 49.8W

NEXT ADVISORY AT 04/0300Z

$$
FORECASTER BROWN