Hurricane Harvey

Forecast Advisory 12

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117
WTNT24 KNHC 231448
TCMAT4

TROPICAL DEPRESSION HARVEY FORECAST/ADVISORY NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092017
1500 UTC WED AUG 23 2017

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A STORM SURGE WATCH HAS BEEN ISSUED FOR THE COAST OF TEXAS FROM
PORT MANSFIELD TO HIGH ISLAND.

A HURRICANE WATCH HAS BEEN ISSUED FOR THE COAST OF TEXAS FROM NORTH
OF PORT MANSFIELD TO SAN LUIS PASS.

A TROPICAL STORM WATCH HAS BEEN ISSUED FOR THE COAST OF TEXAS FROM
THE MOUTH OF THE RIO GRANDE TO PORT MANSFIELD AND FROM NORTH OF
SAN LUIS PASS TO HIGH ISLAND.

THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WATCH FOR THE
COAST OF MEXICO FROM BOCA DE CATAN TO THE MOUTH OF THE RIO GRANDE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A STORM SURGE WATCH IS IN EFFECT FOR...
* PORT MANSFIELD TO HIGH ISLAND

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH OF PORT MANSFIELD TO SAN LUIS PASS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* BOCA DE CATAN MEXICO TO PORT MANSFIELD TEXAS
* NORTH OF SAN LUIS PASS TO HIGH ISLAND

A STORM SURGE WATCH MEANS THERE IS A POSSIBILILTY 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 WEATHER
SERVICE STORM SURGE WATCH/WARNING GRAPHIC...AVAILABLE AT
HURRICANES.GOV.

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 WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

INTERESTS IN SOUTHWESTERN LOUISIANA SHOULD MONITOR THE PROGRESS OF
THIS SYSTEM FOR POSSIBLE WATCHES THIS AFTERNOON.

TROPICAL DEPRESSION CENTER LOCATED NEAR 21.5N 92.5W AT 23/1500Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 8 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
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 21.5N 92.5W AT 23/1500Z
AT 23/1200Z CENTER WAS LOCATED NEAR 21.4N 92.5W

FORECAST VALID 24/0000Z 22.3N 93.2W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 60NE 0SE 0SW 0NW.

FORECAST VALID 24/1200Z 23.8N 93.9W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 70NE 50SE 30SW 50NW.

FORECAST VALID 25/0000Z 25.2N 94.9W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 40NE 0SE 0SW 0NW.
34 KT... 90NE 70SE 40SW 60NW.

FORECAST VALID 25/1200Z 26.7N 96.3W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 50NE 40SE 20SW 30NW.
34 KT...120NE 90SE 50SW 80NW.

FORECAST VALID 26/1200Z 29.0N 97.3W...INLAND
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 60NE 90SE 30SW 30NW.

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 27/1200Z 29.8N 96.9W...INLAND
MAX WIND 35 KT...GUSTS 45 KT.

OUTLOOK VALID 28/1200Z 30.0N 95.0W...INLAND
MAX WIND 35 KT...GUSTS 45 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.5N 92.5W

NEXT ADVISORY AT 23/2100Z

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FORECASTER BLAKE