Alert archive / Massachusetts / Coastal Flood Statements in 2021

Coastal Flood Statement 8, NWS Boston/Norton, MA

July 23, 20216 counties in Massachusetts

NWS Boston/Norton, MA issued this coastal flood statement at Jul 23, 2021, 2:49 PM EDT for 6 counties in Massachusetts. It took effect at Jul 23, 2021, 10:00 PM EDT. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued: Jul 23, 2021, 2:49 PM EDT (18:49 UTC)
In effect from: Jul 23, 2021, 10:00 PM EDT
Expired: Jul 24, 2021, 2:00 AM EDT
In force: 4 hr
Issued by: NWS Boston/Norton, MA

Counties Barnstable County, MA, Essex County, MA, Nantucket County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 37 km from the middle of the area, began a volume at 18:52 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 6.8 hours before the alert went out and 211 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 16 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 1504 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -5 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

863 
WHUS41 KBOX 231849
CFWBOX

Coastal Hazard Message
National Weather Service Boston/Norton MA
249 PM EDT Fri Jul 23 2021

MAZ007-015-016-019-022-024-240600-
/O.NEW.KBOX.CF.S.0008.210724T0200Z-210724T0600Z/
Eastern Essex MA-Suffolk MA-Eastern Norfolk MA-
Eastern Plymouth MA-Barnstable MA-Nantucket MA-
249 PM EDT Fri Jul 23 2021

* WHAT...Up to one-half foot of inundation above 
  ground level expected in low-lying areas near shorelines and 
  tidal waterways (3.0 to 12.4 feet Mean Lower Low Water).

* WHERE...Eastern Plymouth MA, Suffolk MA, Eastern Essex MA, 
  Barnstable MA, Eastern Norfolk MA and Nantucket MA Counties.

* WHEN...From 10 PM this evening to 2 AM EDT Saturday.

* IMPACTS...Minor splashover on typically vulnerable shoreline roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

&&

Time of high total tides are approximate to the nearest hour.

Merrimack River near Newburyport MA
MLLW Categories - Minor 11.0 ft, Moderate 12.0 ft, Major 13.5 ft
MHHW Categories - Minor 1.5 ft, Moderate 2.5 ft, Major 4.0 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/12 AM   9.9/10.4   0.4/ 0.9   0.1/ 0.6     1       None    
 24/12 PM   8.3/ 8.8  -1.3/-0.8   0.1/ 0.6     1       None    
 25/01 AM  10.1/10.6   0.6/ 1.1   0.2/ 0.8     1       None

Gloucester Harbor
MLLW Categories - Minor 11.5 ft, Moderate 13.0 ft, Major 15.0 ft
MHHW Categories - Minor 2.0 ft, Moderate 3.5 ft, Major 5.5 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 23/11 PM  11.1/11.6   1.6/ 2.0   0.1/ 0.6     1      Minor    
 24/12 PM   9.4/ 9.9  -0.2/ 0.3   0.0/ 0.5     1       None    
 25/12 AM  11.0/11.5   1.5/ 2.0   0.1/ 0.6     2       None

Revere
MLLW Categories - Minor 12.5 ft, Moderate 14.5 ft, Major 16.0 ft
MHHW Categories - Minor 2.6 ft, Moderate 4.6 ft, Major 6.1 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 23/11 PM  11.5/12.0   1.6/ 2.0   0.2/ 0.7     1       None    
 24/12 PM   9.9/10.4   0.0/ 0.5   0.2/ 0.7     1       None    
 25/12 AM  11.5/12.0   1.6/ 2.0   0.2/ 0.7     1       None

Boston Harbor
MLLW Categories - Minor 12.5 ft, Moderate 14.5 ft, Major 16.0 ft
MHHW Categories - Minor 2.4 ft, Moderate 4.4 ft, Major 5.9 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 23/11 PM  11.7/12.2   1.6/ 2.0   0.2/ 0.7     1       None    
 24/12 PM  10.0/10.5  -0.2/ 0.3   0.2/ 0.7     1       None    
 25/12 AM  11.6/12.1   1.5/ 2.0   0.2/ 0.7     1       None

Scituate MA
MLLW Categories - Minor 11.5 ft, Moderate 13.5 ft, Major 15.5 ft
MHHW Categories - Minor 1.8 ft, Moderate 3.8 ft, Major 5.8 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/12 AM  11.1/11.6   1.4/ 1.9   0.1/ 0.6     1      Minor    
 24/12 PM   9.3/ 9.8  -0.5/ 0.0   0.0/ 0.5     1       None    
 25/12 AM  11.0/11.5   1.3/ 1.8   0.1/ 0.6     1       None

Chatham - South side
MLLW Categories - Minor 9.0 ft, Moderate 10.5 ft, Major 11.5 ft
MHHW Categories - Minor 4.5 ft, Moderate 6.0 ft, Major 7.0 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/01 AM   5.7/ 6.2   1.2/ 1.7   0.7/ 1.1     1       None    
 24/02 PM   4.2/ 4.7  -0.2/ 0.2   0.6/ 1.1     1       None    
 25/01 AM   5.5/ 6.0   1.0/ 1.5   0.6/ 1.1     1       None

Wings Neck
MLLW Categories - Minor 6.5 ft, Moderate 9.0 ft, Major 11.5 ft
MHHW Categories - Minor 2.1 ft, Moderate 4.6 ft, Major 7.1 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 23/08 PM   5.4/ 5.9   1.0/ 1.5   0.2/ 0.7     1       None    
 24/09 AM   4.6/ 5.1   0.2/ 0.7   0.1/ 0.6     1       None    
 24/09 PM   5.2/ 5.7   0.9/ 1.4   0.2/ 0.7     1       None    
 25/10 AM   4.9/ 5.4   0.5/ 1.0   0.4/ 0.9     1       None

Provincetown Harbor
MLLW Categories - Minor 13.0 ft, Moderate 14.0 ft, Major 15.0 ft
MHHW Categories - Minor 2.9 ft, Moderate 3.9 ft, Major 4.9 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/12 AM  11.5/12.0   1.4/ 1.9   0.1/ 0.6     1       None    
 24/12 PM   9.7/10.2  -0.5/ 0.0   0.0/ 0.5     1       None    
 25/12 AM  11.3/11.8   1.2/ 1.7   0.0/ 0.5     1       None

Buzzards Bay at Woods Hole
MLLW Categories - Minor 5.5 ft, Moderate 7.0 ft, Major 8.5 ft
MHHW Categories - Minor 3.5 ft, Moderate 5.0 ft, Major 6.5 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 23/08 PM   3.2/ 3.7   1.2/ 1.7   0.1/ 0.6     1       None    
 24/09 AM   2.7/ 3.2   0.7/ 1.1   0.1/ 0.6     1       None    
 24/09 PM   3.1/ 3.6   1.1/ 1.6   0.1/ 0.6     1       None    
 25/10 AM   2.8/ 3.4   0.9/ 1.4   0.2/ 0.7     1       None

Dennis - Sesuit Harbor
MLLW Categories - Minor 13.0 ft, Moderate 14.5 ft, Major 16.0 ft
MHHW Categories - Minor 2.5 ft, Moderate 4.0 ft, Major 5.5 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/12 AM  12.2/12.7   1.7/ 2.2   0.2/ 0.8     1       None    
 24/12 PM  10.4/10.9  -0.2/ 0.3   0.2/ 0.7     1       None    
 25/12 AM  11.9/12.4   1.4/ 1.9   0.1/ 0.6     1       None

Chatham MA - East Coast
MLLW Categories - Minor 9.0 ft, Moderate 11.5 ft, Major 13.0 ft
MHHW Categories - Minor 1.3 ft, Moderate 3.8 ft, Major 5.3 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/12 AM   6.2/ 6.8  -1.5/-1.0   0.4/ 0.9     1       None    
 24/01 PM   5.0/ 5.5  -2.7/-2.2   0.4/ 0.9     1       None    
 25/02 AM   6.2/ 6.8  -1.5/-1.0   0.6/ 1.1     2       None

Sandwich Harbor
MLLW Categories - Minor 12.0 ft, Moderate 14.0 ft, Major 15.0 ft
MHHW Categories - Minor 1.7 ft, Moderate 3.7 ft, Major 4.7 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 23/11 PM  10.4/10.9   0.1/ 0.6   0.1/ 0.6     1       None    
 24/12 PM   8.8/ 9.3  -1.6/-1.1   0.1/ 0.6     1       None    
 25/12 AM  10.3/10.8   0.0/ 0.5   0.1/ 0.6     1       None

Nantucket Harbor
MLLW Categories - Minor 5.0 ft, Moderate 6.5 ft, Major 8.0 ft
MHHW Categories - Minor 1.4 ft, Moderate 2.9 ft, Major 4.4 ft

             Total      Total    Departure                   
 Day/Time    Tide       Tide     from Norm   Waves    Flood  
            ft MLLW    ft MHHW       ft       ft      Impact 
 --------  ---------  ---------  ---------  -------  --------
 24/01 AM   4.5/ 5.0   0.9/ 1.4   0.5/ 1.0     1       None    
 24/01 PM   3.2/ 3.7  -0.3/ 0.2   0.4/ 0.9     1       None    
 25/01 AM   4.2/ 4.7   0.7/ 1.1   0.4/ 0.9     1       None

&&

$$

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 23, 2:28 PM EDT	Special Weather Statement	BOX	Middlesex	32 min
Jul 23, 3:04 PM EDT	Special Weather Statement	BOX	Essex	26 min
Jul 23, 3:28 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	47 min
Jul 23, 3:29 PM EDT	Special Marine Warning	BOX		61 min
Jul 23, 4:41 PM EDT	Special Weather Statement	BOX	Essex	34 min
Jul 23, 4:57 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	63 min
Jul 23, 5:23 PM EDT	Special Weather Statement	BOX	Bristol	52 min
Jul 23, 5:50 PM EDT	Special Marine Warning	BOX		55 min
Jul 23, 6:09 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Plymouth	26 min
Jul 23, 6:25 PM EDT	Special Weather Statement	BOX	Plymouth	50 min
Jul 23, 6:32 PM EDT	Special Weather Statement	BOX	Worcester	43 min
Jul 23, 6:42 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Plymouth	48 min
Jul 23, 7:28 PM EDT	Severe Thunderstorm Warning	BOX	Plymouth	34 min

Nearby

Coastal Flood Statements in Massachusetts, 2021 Every coastal flood statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.