Coastal flood warning

A coastal flood warning is an hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service in the United States which indicates coastal flooding is either imminent or occurring along the coast of the Atlantic Ocean, Pacific Ocean, or the Gulf of Mexico. The flooding must be due to water being forced from the nearby body of water onto the land, and not from rainfall. Nor'easters, hurricanes, tropical storms, and thunderstorms can all lead to the issuance of a coastal flood warning.

Example
The following is an example of a coastal flood warning issued by the National Weather Service office in Boston, Massachusetts.

000 WHUS41 KBOX 071920 CFWBOX

URGENT - IMMEDIATE BROADCAST REQUESTED COASTAL HAZARD MESSAGE NATIONAL WEATHER SERVICE TAUNTON MA 220 PM EST THU FEB 7 2013

...COASTAL FLOOD WARNING FOR THE MASSACHUSETTS EAST FACING COASTLINE AROUND THE TIME OF THE FRIDAY EVENING AND SATURDAY MORNING HIGH TIDES...

.A POWERFUL COASTAL STORM WILL PRODUCE MODERATE COASTAL FLOODING FRIDAY EVENING AND MODERATE TO MAJOR COASTAL FLOODING SATURDAY MORNING ALONG WITH POTENTIALLY SEVERE EROSION. LARGE WAVES COMBINED WITH A 2 TO 3 FOOT STORM SURGE MAY CAUSE A NUMBER OF VULNERABLE SHORE ROADS TO BECOME IMPASSABLE FOR A WHILE...AND MAY CAUSE DAMAGE TO HOMES ALONG THE IMMEDIATE SHORELINE DURING THE SATURDAY MORNING HIGH TIDE.

MAZ007-015-016-019-022>024-080330- /O.NEW.KBOX.CF.W.0001.130209T0100Z-130209T1700Z/ /O.EXT.KBOX.CF.A.0001.130209T1700Z-130209T1800Z/ EASTERN ESSEX MA-SUFFOLK MA-EASTERN NORFOLK MA- EASTERN PLYMOUTH MA-BARNSTABLE MA-DUKES MA-NANTUCKET MA- 220 PM EST THU FEB 7 2013

...COASTAL FLOOD WARNING IN EFFECT FROM 8 PM FRIDAY TO NOON EST SATURDAY...

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A COASTAL FLOOD WARNING...WHICH IS IN EFFECT FROM 8 PM FRIDAY TO NOON EST SATURDAY.


 * LOCATION...EAST FACING COASTLINE OF MASSACHUSETTS

FRIDAY EVENING HIGH TIDE AND MODERATE TO MAJOR COASTAL FLOODING IS LIKELY FOR THE SATURDAY MORNING HIGH TIDE...WITH THE MOST SEVERE IMPACT EXPECTED ALONG EAST AND NORTH FACING SHORELINES SOUTH OF BOSTON.
 * COASTAL FLOODING...MODERATE COASTAL FLOODING IS LIKELY FOR THE


 * TIMING...FRIDAY EVENING AND SATURDAY MORNING HIGH TIDES

FOR A TIME FRIDAY EVENING. COASTAL FLOODING AROUND THE SATURDAY MORNING HIGH TIDE WILL LIKELY CAUSE NUMEROUS SHORE ROADS TO BECOME IMPASSABLE AND PUT SOME STRUCTURES AT RISK ALONG THE IMMEDIATE SHORE...ESPECIALLY THOSE VULNERABLE LOCATIONS SOUTH OF BOSTON FROM HULL TO SANDWICH. SEVERE BEACH EROSION WILL ALSO OCCUR...ESPECIALLY DURING THE SATURDAY MORNING HIGH TIDE.
 * IMPACTS...A NUMBER OF SHORE ROADS WILL LIKELY BECOME IMPASSABLE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A COASTAL FLOOD WARNING MEANS THAT MODERATE OR MAJOR COASTAL FLOODING IS LIKELY. MODERATE COASTAL FLOODING PRODUCES WIDESPREAD FLOODING OF VULNERABLE SHORE ROADS AND/OR BASEMENTS DUE TO THE HEIGHT OF STORM TIDE AND/OR WAVE ACTION. NUMEROUS ROAD CLOSURES ARE NEEDED. LIVES MAY BE AT RISK FOR PEOPLE WHO PUT THEMSELVES IN HARMS WAY. ISOLATED STRUCTURAL DAMAGE MAY BE OBSERVED.

MAJOR COASTAL FLOODING IS CONSIDERED SEVERE ENOUGH TO CAUSE AT LEAST SCATTERED STRUCTURAL DAMAGE ALONG WITH WIDESPREAD FLOODING OF VULNERABLE SHORE ROADS AND/OR BASEMENTS. SOME VULNERABLE HOMES MAY BE SEVERELY DAMAGED OR DESTROYED. EVACUATION OF SOME NEIGHBORHOODS MAY BE NECESSARY.

&&

&&

ALL TIDE HEIGHTS ARE RELATIVE TO MEAN LOWER LOW WATER. TIME OF HIGH TOTAL TIDES ARE APPROXIMATE TO THE NEAREST HOUR.

NEWBURYPORT

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     8.3    07/09 PM     8.3      0.0       1        NONE 9.9   08/09 AM     9.7      0.2      2-3       NONE 11.1   08/10 PM     8.6      2.5      8-13     MINOR 12.1   09/10 AM     9.9      2.2       21     MDT-MAJOR 9.0   09/11 PM     9.0      0.0      8-10      NONE 10.0   10/11 AM    10.0      0.0       5        NONE

GLOUCESTER HARBOR

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     9.1    07/09 PM     9.1      0.0       1        NONE 11.0   08/09 AM    10.7      0.3      3-4       NONE 12.0   08/10 PM     9.5      2.5     12-18     MINOR 13.1   09/10 AM    10.9      2.2       21     MODERATE 9.8   09/11 PM     9.8      0.0       10       NONE 10.9   10/11 AM    10.9      0.0      6-7       NONE

REVERE

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     9.6    07/09 PM     9.6      0.0       1        NONE 11.4   08/09 AM    11.2      0.2      2-3       NONE 12.5   08/10 PM    10.0      2.5      8-12     MINOR 14.0   09/10 AM    11.5      2.5       13     MDT-MAJOR 10.3   09/11 PM    10.3      0.0      7-9       NONE 11.5   10/11 AM    11.5      0.0       5        NONE

BOSTON HARBOR

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     9.6    07/09 PM     9.6      0.0       1        NONE 11.4   08/09 AM    11.2      0.2       2        NONE 12.8   08/10 PM    10.0      2.8      3-4     MODERATE 14.0   09/10 AM    11.5      2.5       3      MODERATE 10.3   09/11 PM    10.3      0.0      2-3       NONE 11.5   10/11 AM    11.5      0.0       1        NONE

SCITUATE

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     9.4    07/09 PM     9.4      0.0       1        NONE 11.3   08/09 AM    11.0      0.3      3-4      MINOR 12.6   08/10 PM     9.8      2.8      8-17    MODERATE 14.2   09/10 AM    11.2      3.0       26      MAJOR 10.1   09/11 PM    10.1      0.0     10-13      NONE 11.3   10/11 AM    11.3      0.0      6-7      MINOR

SANDWICH HARBOR

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     9.0    07/09 PM     9.0      0.0      1-2       NONE 11.1   08/09 AM    10.5      0.6      2-3       NONE 12.5   08/10 PM     9.4      3.1      7-11    MODERATE 14.7   09/10 AM    10.7      4.0       20      MAJOR 9.7   09/11 PM     9.7      0.0      6-8       NONE 10.8   10/11 AM    10.8      0.0      3-4       NONE

PROVINCETOWN HARBOR

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     9.6    07/09 PM     9.6      0.0       1        NONE 11.4   08/09 AM    11.1      0.3      2-3       NONE 11.3   08/10 PM     9.9      1.4      7-12     MINOR 12.6   09/10 AM    11.3      1.3       15     MODERATE 10.2   09/11 PM    10.2      0.0      8-10      NONE 11.4   10/11 AM    11.4      0.0       5        NONE

CHATHAM - EAST COAST

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     4.2    07/09 PM     4.2      0.0      2-3       NONE 6.0   08/10 AM     5.3      0.7      4-6       NONE 7.4   08/10 PM     4.4      3.0     12-16      NONE 8.3   09/11 AM     5.3      3.0       32     MDT-MAJOR 4.6   09/11 PM     4.6      0.0     12-15      NONE

CHATHAM - SOUTH COAST

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     4.0    07/10 PM     4.0      0.0      1-2       NONE 5.6   08/10 AM     5.2      0.4      3-5       NONE 5.4   08/11 PM     4.2      1.2      8-9       NONE 5.7   09/11 AM     5.2      0.5       10       NONE 4.3   09/11 PM     4.3      0.0      6-7       NONE

BUZZARDS BAY - WOODS HOLE

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     2.1    07/06 PM     2.1      0.0       1        NONE 3.1   08/06 AM     2.9      0.2       2        NONE 2.9   08/06 PM     2.2      0.7      4-6       NONE 3.0   09/07 AM     2.9      0.1      7-8       NONE 2.4   10/07 PM     2.4      0.0      3-4       NONE 2.8   10/08 AM     2.8      0.0       2        NONE

VINEYARD HAVEN

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     2.2    07/09 PM     2.2      0.0       1        NONE 3.5   08/09 AM     3.0      0.5       3        NONE 5.1   08/10 PM     2.3      2.8      6-8      MINOR 3.2   09/10 AM     3.0      0.2       8        NONE 2.4   09/11 PM     2.4      0.0      3-4       NONE 2.9   10/11 AM     2.9      0.0      1-2       NONE

NANTUCKET HARBOR

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     3.2    07/10 PM     3.2      0.0       2        NONE 4.8   08/10 AM     4.2      0.6      3-5      MINOR 6.3   08/11 PM     3.3      3.0      8-10    MODERATE 6.1   09/11 AM     4.2      1.9       10     MODERATE 3.5   10/12 AM     3.4      0.1      5-6       NONE

NANTUCKET EAST COAST

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     3.3    07/09 PM     3.3      0.0      2-3       NONE 4.8   08/10 AM     4.4      0.4      4-6       NONE 6.4   08/10 PM     3.4      3.0     12-14    MODERATE 7.6   09/11 AM     4.4      3.2       29      MAJOR 3.6   09/11 PM     3.6      0.0     10-12      NONE

NANTUCKET SOUTH COAST

TOTAL               ASTRO TIDE   DAY/TIME     TIDE    SURGE    WAVES      FLOOD /FT/                /FT/     /FT/     /FT/    CATEGORY --- --  ---  ---  ---  --     3.1    07/10 PM     3.1      0.0      2-3       NONE 4.6   08/10 AM     4.2      0.4      4-6       NONE 4.3   08/10 PM     3.2      1.1     12-14      NONE 4.6   09/11 AM     4.2      0.4       17       NONE 3.4   10/12 AM     3.4      0.0      7-8       NONE

$$

THOMPSON