Alert archive / Massachusetts / Coastal Flood Statements in 2020

Coastal Flood Statement 2, NWS Boston/Norton, MA

March 10, 2020Essex County, Massachusetts

NWS Boston/Norton, MA issued this coastal flood statement at Mar 10, 2020, 4:20 AM EDT for Essex County, Massachusetts. It took effect at Mar 10, 2020, 10:00 AM EDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Mar 10, 2020, 4:20 AM EDT (08:20 UTC)
In effect from
Mar 10, 2020, 10:00 AM EDT
Expired
Mar 10, 2020, 3:00 PM EDT
In force
5 hr
Issued by
NWS Boston/Norton, MA

County Essex County, MA

The radar

The Boston radar (KBOX), 79 km from the middle of the area, began a volume at 08:20 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

Chatham, MA (KCHH), launched 00:00Z, 8.3 hours before the alert went out and 131 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-pSkew-T log-p diagram, Chatham, MA at 00:00Z on 2020-03-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Chatham, MA at 00:00Z on 2020-03-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 178 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2701 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
178 m²/s²
0-3 km storm-relative helicity
250 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

805 
WHUS41 KBOX 100820
CFWBOX

Coastal Hazard Message
National Weather Service Boston/Norton MA
420 AM EDT Tue Mar 10 2020

MAZ022-101700-
/O.NEW.KBOX.CF.Y.0002.200310T1400Z-200310T1900Z/
Barnstable MA-
420 AM EDT Tue Mar 10 2020

...COASTAL FLOOD ADVISORY IN EFFECT FROM 10 AM THIS MORNING TO
3 PM EDT THIS AFTERNOON...

* WHAT...Up to one foot of inundation above ground level 
  expected in low-lying areas near shorelines and tidal 
  waterways (3.7 to 13.2 feet Mean Lower Low Water).

* WHERE...Barnstable MA County.

* WHEN...From 10 AM this morning to 3 PM EDT this afternoon.

* IMPACTS...Minor coastal flooding is forecast for Cape Cod Bay at 
  Sesuit Harbor around the time of high tide early this afternoon. 
  Minor flooding of lowest-lying areas nearest the shoreline is 
  anticipated.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

&&

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

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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM   4.5/ 5.0   0.0/ 0.5   0.2/ 0.7    2-3      None    
 11/02 AM   4.0/ 4.5  -0.5/ 0.0   0.0/ 0.5    2-3      None    
 11/02 PM   4.2/ 4.7  -0.2/ 0.2   0.0/ 0.5     1       None    
 12/03 AM   4.4/ 4.9  -0.2/ 0.3   0.1/ 0.6     1       None    
 12/03 PM   4.2/ 4.7  -0.3/ 0.2   0.1/ 0.6    1-2      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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM   5.4/ 5.9  -2.3/-1.9  -0.2/ 0.2    3-4      None    
 11/02 AM   5.0/ 5.5  -2.7/-2.2  -0.3/ 0.2    3-4      None    
 11/02 PM   5.2/ 5.7  -2.6/-2.1  -0.3/ 0.2    3-4      None    
 12/03 AM   5.2/ 5.7  -2.5/-2.0  -0.2/ 0.2     2       None    
 12/03 PM   5.0/ 5.5  -2.7/-2.2  -0.3/ 0.2     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 
 --------  ---------  ---------  ---------  -------  --------
 10/12 PM  11.4/11.9   1.1/ 1.6   1.0/ 1.5    1-2      None    
 11/01 AM  10.8/11.3   0.5/ 1.0   0.7/ 1.1    1-2      None    
 11/01 PM  11.1/11.6   0.8/ 1.3   0.7/ 1.1    2-3      None    
 12/02 AM  11.2/11.7   0.9/ 1.4   0.9/ 1.4     1       None    
 12/02 PM  10.9/11.4   0.6/ 1.1   0.8/ 1.3     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 
 --------  ---------  ---------  ---------  -------  --------
 10/09 AM   5.4/ 5.9   1.0/ 1.5   0.5/ 1.0     1       None    
 10/10 PM   5.7/ 6.2   1.4/ 1.9   0.7/ 1.1     2       None    
 11/10 AM   5.0/ 5.5   0.6/ 1.1   0.2/ 0.7     1       None    
 11/10 PM   5.2/ 5.7   0.9/ 1.4   0.2/ 0.7     1       None    
 12/11 AM   4.9/ 5.4   0.5/ 1.0   0.2/ 0.8     1       None    
 12/11 PM   5.4/ 5.9   1.0/ 1.5   0.4/ 0.9     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 
 --------  ---------  ---------  ---------  -------  --------
 10/09 AM   3.6/ 4.1   1.6/ 2.0   0.8/ 1.3    1-2      None    
 10/10 PM   3.9/ 4.4   1.9/ 2.3   0.9/ 1.4    2-3      None    
 11/10 AM   3.5/ 4.0   1.5/ 2.0   0.7/ 1.1     1       None    
 11/11 PM   3.7/ 4.2   1.7/ 2.2   0.7/ 1.1     1       None    
 12/11 AM   3.4/ 3.9   1.4/ 1.9   0.8/ 1.3     1       None    
 13/12 AM   3.9/ 4.4   1.9/ 2.3   1.1/ 1.6    1-2      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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM  13.0/13.5   2.5/ 3.0   1.0/ 1.5    1-2     Minor    
 11/01 AM  12.5/13.0   2.0/ 2.5   0.8/ 1.3    1-2      None    
 11/01 PM  12.8/13.3   2.2/ 2.7   0.8/ 1.3    1-2     Minor    
 12/02 AM  12.9/13.4   2.3/ 2.8   0.9/ 1.4     1      Minor    
 12/02 PM  12.6/13.1   2.1/ 2.6   0.8/ 1.3     1      Minor

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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM  12.3/12.8   2.2/ 2.7   0.9/ 1.4    2-4      None    
 11/01 AM  11.7/12.2   1.6/ 2.0   0.7/ 1.1    2-4      None    
 11/01 PM  12.0/12.5   1.9/ 2.3   0.7/ 1.1     1       None    
 12/02 AM  12.0/12.5   1.9/ 2.3   0.8/ 1.3     1       None    
 12/02 PM  11.7/12.2   1.6/ 2.0   0.7/ 1.1     1       None

&&

$$

MAZ007-101700-
/O.NEW.KBOX.CF.S.0002.200310T1400Z-200310T1900Z/
Eastern Essex MA-
420 AM EDT Tue Mar 10 2020

* WHAT...Minor splashover with up to one-half foot of inundation 
  above ground level expected in low-lying areas near shorelines 
  and tidal waterways (9.7 to 11.5 feet Mean Lower Low Water).

* WHERE...Eastern Essex MA County.

* WHEN...From 10 AM this morning to 3 PM EDT this afternoon.

* IMPACTS...Minor splashover is expected along the North 
  Shore from Gloucester to Newburyport around the early-afternoon 
  high tide. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

&&

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

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 
 --------  ---------  ---------  ---------  -------  --------
 10/12 PM  11.3/11.8   1.8/ 2.2   0.1/ 0.6    1-2     Minor    
 11/01 AM  10.6/11.1   1.1/ 1.6  -0.2/ 0.2     3       None    
 11/01 PM  11.0/11.5   1.5/ 2.0  -0.2/ 0.2    1-2      None    
 12/02 AM  10.9/11.4   1.4/ 1.9  -0.2/ 0.3     1       None    
 12/02 PM  10.8/11.3   1.3/ 1.8  -0.2/ 0.3     2       None

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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM   9.5/10.0   0.0/ 0.5  -0.2/ 0.2     1       None    
 11/01 AM   9.2/ 9.7  -0.3/ 0.2  -0.2/ 0.2     1       None    
 11/02 PM   9.5/10.0   0.0/ 0.5  -0.2/ 0.2     1       None    
 12/02 AM   9.5/10.0   0.0/ 0.5  -0.2/ 0.2     1       None    
 12/02 PM   9.3/ 9.8  -0.2/ 0.2  -0.2/ 0.2     1       None

&&

$$
1 follow-up statement
827 
WHUS41 KBOX 101420
CFWBOX

Coastal Hazard Message
National Weather Service Boston/Norton MA
1020 AM EDT Tue Mar 10 2020

MAZ022-101900-
/O.CON.KBOX.CF.Y.0002.000000T0000Z-200310T1900Z/
Barnstable MA-
1020 AM EDT Tue Mar 10 2020

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 3 PM EDT THIS
AFTERNOON...

* WHAT...Up to one foot of inundation above ground level 
  expected in low-lying areas near shorelines and tidal 
  waterways (3.7 to 13.2 feet Mean Lower Low Water).

* WHERE...Barnstable MA County.

* WHEN...From 10 AM this morning to 3 PM EDT this afternoon.

* IMPACTS...Minor coastal flooding is forecast for Cape Cod Bay 
  at Sesuit Harbor around the time of high tide early this 
  afternoon. Minor flooding of lowest-lying areas nearest the 
  shoreline is anticipated.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

&&

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

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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM   4.5/ 5.0   0.0/ 0.5   0.2/ 0.7    2-3      None    
 11/02 AM   4.0/ 4.5  -0.5/ 0.0   0.0/ 0.5    2-3      None    
 11/02 PM   4.2/ 4.7  -0.2/ 0.2   0.0/ 0.5     1       None    
 12/03 AM   4.4/ 4.9  -0.2/ 0.3   0.1/ 0.6     1       None    
 12/03 PM   4.2/ 4.7  -0.3/ 0.2   0.1/ 0.6    1-2      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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM   5.4/ 5.9  -2.3/-1.9  -0.2/ 0.2    3-4      None    
 11/02 AM   5.0/ 5.5  -2.7/-2.2  -0.3/ 0.2    3-4      None    
 11/02 PM   5.2/ 5.7  -2.6/-2.1  -0.3/ 0.2    3-4      None    
 12/03 AM   5.2/ 5.7  -2.5/-2.0  -0.2/ 0.2     2       None    
 12/03 PM   5.0/ 5.5  -2.7/-2.2  -0.3/ 0.2     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 
 --------  ---------  ---------  ---------  -------  --------
 10/12 PM  11.4/11.9   1.1/ 1.6   1.0/ 1.5    1-2      None    
 11/01 AM  10.8/11.3   0.5/ 1.0   0.7/ 1.1    1-2      None    
 11/01 PM  11.1/11.6   0.8/ 1.3   0.7/ 1.1    2-3      None    
 12/02 AM  11.2/11.7   0.9/ 1.4   0.9/ 1.4     1       None    
 12/02 PM  10.9/11.4   0.6/ 1.1   0.8/ 1.3     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 
 --------  ---------  ---------  ---------  -------  --------
 10/09 AM   5.4/ 5.9   1.0/ 1.5   0.5/ 1.0     1       None    
 10/10 PM   5.7/ 6.2   1.4/ 1.9   0.7/ 1.1     2       None    
 11/10 AM   5.0/ 5.5   0.6/ 1.1   0.2/ 0.7     1       None    
 11/10 PM   5.2/ 5.7   0.9/ 1.4   0.2/ 0.7     1       None    
 12/11 AM   4.9/ 5.4   0.5/ 1.0   0.2/ 0.8     1       None    
 12/11 PM   5.4/ 5.9   1.0/ 1.5   0.4/ 0.9     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 
 --------  ---------  ---------  ---------  -------  --------
 10/09 AM   3.6/ 4.1   1.6/ 2.0   0.8/ 1.3    1-2      None    
 10/10 PM   3.9/ 4.4   1.9/ 2.3   0.9/ 1.4    2-3      None    
 11/10 AM   3.5/ 4.0   1.5/ 2.0   0.7/ 1.1     1       None    
 11/11 PM   3.7/ 4.2   1.7/ 2.2   0.7/ 1.1     1       None    
 12/11 AM   3.4/ 3.9   1.4/ 1.9   0.8/ 1.3     1       None    
 13/12 AM   3.9/ 4.4   1.9/ 2.3   1.1/ 1.6    1-2      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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM  13.0/13.5   2.5/ 3.0   1.0/ 1.5    1-2     Minor    
 11/01 AM  12.5/13.0   2.0/ 2.5   0.8/ 1.3    1-2      None    
 11/01 PM  12.8/13.3   2.2/ 2.7   0.8/ 1.3    1-2     Minor    
 12/02 AM  12.9/13.4   2.3/ 2.8   0.9/ 1.4     1      Minor    
 12/02 PM  12.6/13.1   2.1/ 2.6   0.8/ 1.3     1      Minor

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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM  12.3/12.8   2.2/ 2.7   0.9/ 1.4    2-4      None    
 11/01 AM  11.7/12.2   1.6/ 2.0   0.7/ 1.1    2-4      None    
 11/01 PM  12.0/12.5   1.9/ 2.3   0.7/ 1.1     1       None    
 12/02 AM  12.0/12.5   1.9/ 2.3   0.8/ 1.3     1       None    
 12/02 PM  11.7/12.2   1.6/ 2.0   0.7/ 1.1     1       None

&&

$$

MAZ007-101900-
/O.CON.KBOX.CF.S.0002.000000T0000Z-200310T1900Z/
Eastern Essex MA-
1020 AM EDT Tue Mar 10 2020

* WHAT...Minor splashover with up to one-half foot of inundation 
  above ground level expected in low-lying areas near shorelines 
  and tidal waterways (9.7 to 11.5 feet Mean Lower Low Water).

* WHERE...Eastern Essex MA County.

* WHEN...From 10 AM this morning to 3 PM EDT this afternoon.

* IMPACTS...Minor splashover is expected along the North Shore 
  from Gloucester to Newburyport around the early-afternoon high 
  tide.

* ADDITIONAL DETAILS...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

&&

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

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 
 --------  ---------  ---------  ---------  -------  --------
 10/12 PM  11.3/11.8   1.8/ 2.2   0.1/ 0.6    1-2     Minor    
 11/01 AM  10.6/11.1   1.1/ 1.6  -0.2/ 0.2     3       None    
 11/01 PM  11.0/11.5   1.5/ 2.0  -0.2/ 0.2    1-2      None    
 12/02 AM  10.9/11.4   1.4/ 1.9  -0.2/ 0.3     1       None    
 12/02 PM  10.8/11.3   1.3/ 1.8  -0.2/ 0.3     2       None

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 
 --------  ---------  ---------  ---------  -------  --------
 10/01 PM   9.5/10.0   0.0/ 0.5  -0.2/ 0.2     1       None    
 11/01 AM   9.2/ 9.7  -0.3/ 0.2  -0.2/ 0.2     1       None    
 11/02 PM   9.5/10.0   0.0/ 0.5  -0.2/ 0.2     1       None    
 12/02 AM   9.5/10.0   0.0/ 0.5  -0.2/ 0.2     1       None    
 12/02 PM   9.3/ 9.8  -0.2/ 0.2  -0.2/ 0.2     1       None

&&

$$

What forecasters said that day

The local office's own words before this coastal flood statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Boston/Norton, MA wrote its last area forecast discussion before this coastal flood statement went out at Mar 10, 1:40 AM EDT, 2 hours 40 minutes earlier.

Area forecast discussion, Mar 10, 1:40 AM EDT, 2 hours 40 minutes before
Area Forecast Discussion
National Weather Service Boston/Norton MA
140 AM EDT Tue Mar 10 2020

.SYNOPSIS...
High pressure off the Mid Atlantic coast will result in a
southwest flow of unseasonably mild conditions tonight. A
cold front will push across the region Tuesday night into
Wednesday morning. High pressure moves in behind the front
Wednesday afternoon, bringing dry conditions and mild
temperatures through Thursday, though cooler than on Tuesday.
Another weather system pushes across Thursday night into
Friday with unsettled conditions. Dry and cool weather is
forecast for next weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1030 PM Update...

Forecast is generally holding up well, though significant local
variation in temperatures are evident due largely to
differences in mixing/wind speed. One need only look at Jaffrey
and Keene, NH currently in the mid-40s, while nearby sites such
as Fitchburg and Orange are in the 50s to low 60s with slightly
stronger S/SW winds. In general, temperatures are cooler (40s
to near 50) towards the South Coast and the Cape, and some 10
degrees warmer across the interior. Will see high to mid clouds
filter in as the overnight hrs progress, though skies should
stay mostly clear to partly cloudy for the balance of the
overnight with continued S/SW. Lows still look on pace.

Previous Discussion...

High pressure ridging in control today brought dry and warm
weather as SW flow continues around the sfc high to our
southeast. This warm, moist flow has led to exceptionally
warm temperatures today, breaking the record of 70 F in
Providence (they have reached 72 F as of 2PM). The only ones
missing out on the extreme mild temps are immediate south
coast where a cool flow off the water is keeping temperatures
in the mid 50s.

As we go into the overnight hours things remain quiet and warm.
Given warm and moist SW flow together with increasing clouds
after midnight and decent mixing, temperatures won't dip below
the mid 40s tonight; the urban center around Boston could hover
around the 50 degree mark. High clouds filter in toward midnight
ahead of the incoming system, while low/mid clouds don't show
up until mid morning Tuesday.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
Tuesday and especially Tuesday evening/night brings our main
chance of rain for the first half of the week. At the synoptic
scale we see a shortwave trough over the Great Lakes early
Tuesday which crosses New England Tuesday night. At the surface
the low center moves from the eastern Great Lakes into Maine,
placing us in the warm sector during the day before the cold
front moves through Tuesday night. A decent plume of moisture
precedes the front (PWATs >1" and dewpoints in the upper 40s)
and weak isentropic lift together with divergence aloft and a
good LLJ will bring scattered showers in the afternoon followed
by the cold front/one last push of showers Tuesday night between
8pm and midnight.

Temperatures will remain well above normal Tuesday, but cooler
than today given the cloud cover and rain. As the front draws
nearer we will mix rather well in the low level WAA which brings
gusty winds from the LLJ down to the surface. Some model
soundings indicate the potential for a very short period of wind
gusts up to or above 40kts, but given the very short nature of
this higher gust potential and model spread, will stick with a
forecast of winds gusting 25 to 35 mph in the afternoon, locally
up to 45 mph.

The cold front exits after midnight taking the rain and clouds
with it and ushering in a drier airmass. Winds switch from the
SW to NW bringing a period of colder temperatures back to the
region. Lows overnight dip into the upper 30s and low 40s (save
for the high elevations of the Berkshires which could be sub
freezing).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Highlights...

* Cold front pushes offshore early Wednesday, bringing dry
  conditions and cooler temperatures
* High pressure crosses region with continued dry conditions
  Wednesday night and Thursday
* Next system brings rain showers Thu night/Fri, a few snow
  showers possible across higher terrain
* Dry conditions with cooler temperatures next weekend

Details...

Wednesday through Thursday...

Broad high pressure extending from Quebec across the northeast
U.S. will keep dry conditions in place. 12Z model suite suggests
gusty NW winds across E coastal Mass early Wed, but will
diminish as the ridge crosses during the day. Will see high
temps ranging from the mid 40s to around 50 across the higher
terrain and along the coast, up to the lower 50s across the
coastal plain and the CT valley.

With a nearly zonal mid level steering flow across the northern
tier states, this high will expand as it crosses New England
Wednesday night and Thursday. Dry conditions will dominate
during this timeframe with light and variable winds Wed night
that will shift to E-SE during Thu. Will also see some clouds
from time to time especially across central and western areas as
well. Temps will be a few degrees cooler than on Wed with the
onshore component.

Thursday night and Friday...

High pres shifts eastward to the Maritimes and western Atlc by
Thu evening, with winds veering from SE to S-SW as the next
system approaches. Surface low pressure and associated front
begins to shift E out of the Great Lakes and Ohio valley. Also
noting cutoff H5 low pressure across western Ontario with a
digging mid level trough into the northern Plains Thu night.

Beyond Thu night, noting increasing model solution spread,
namely with the timing and track of the approaching cold front.
Used a blend of model solutions, which turned out pretty close
to the previous forecast. Noting a rather deep low pres S of
Hudson Bay overnight into Fri morning, with a E-SE wind between
this low and the Maritimes high in place. This will help advect
low level moisture which will enhance the precip especially
across the interior mainly between 09Z to 15Z Fri. Could see up
to 0.25 to 0.50 inches of precip across inland areas by late
Fri, highest across the E slopes of the Berkshires.

Some question whether there could be a little bit of mixed
rain/snow showers across the higher terrain for a time overnight
Thu night. With a non-diurnal temp trend, this chance, if it
does occur, should not last too long.

The precip should start to taper off across N central CT by
late afternoon, while a few showers may linger elsewhere.

Temps will range from the mid 40s to lower 50s on Thu with the
easterly wind flow. However, looks a few degrees milder on Fri
with a more southerly component in place with readings in the
50s as the cold front swings across.

Friday night through Monday...

The cold front will clear the E coast Fri evening as drier air
works in. Will see some leftover showers across the region, but
should push E off the coast by around 05Z. Winds shift to W with
some gusts up to around 20 kt across the higher terrain and
possibly as high as 25-30 kt along the coast mainly after
midnight.

Rather low confidence from Saturday through next Monday due to
wide model solution spread in place as the low exits the
Maritimes.

At this point, should be a dry weekend. Will be blustery on
Saturday with W winds gusting up to around 25 kt, making it feel
cooler than the highs which will range from the lower-mid 40s
across the higher terrain to around 50 across the coastal plain.
Should see dry conditions but cooler temps, running up to 5
degrees below normal on Sunday as a large high extends from
Quebec across New England.

A lot of questions on the sensible weather for Monday as the
high exits the east coast. At this point, winds should veer to
SE, but the timing and track of the next system very much in
question. Have brought in slight chance POPs for now, but low
confidence.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

06z TAF Update:

Rest of the Overnight: High confidence.

VFR. Will need to watch for backdoor front, currently snaking
its way along coastal ME into the ME/NH border. High- res
models indicate NE/E wind shift into NE MA into BOS around
09-11z. Otherwise, areas of low- level wind shear to continue
given strong SW jet above shallow inversion.

Today: High confidence.

VFR with lowering/thickening trend to clouds today, though will
be mainly mid to high clouds for most of the day. Light frontal
showers then arrive late, around 22-01z W-E, with OVC VFR-MVFR
ceilings to prevail as showers intrude. Visbys should be in
the VFR range, though may briefly drop to MVFR levels in the
interior (near and W of ORH).

Winds mainly SW around 9-12 kt with gusts to 20-27 kt. Lone
exception is potentially at BOS which may see E/SE winds thru
the AM hrs, but will eventually become SW by aftn. Low-level
wind shear to continue eastern/SE TAF sites until SWly gusts get
going.

Tonight: High confidence.

VFR/MVFR early with -SHRA to improve to VFR across
central/western MA 02-04z, then 04-06z across eastern MA. SW
winds gusting to 25-30 kt (highest South Coast/Cape Cod) early,
then become NW around 10-12 kt with gusts 20-25 kt after
midnight post-frontal.

Wednesday: High confidence.

VFR SKC, though mid to high clouds begin to intrude late Wed
across the CT Valley into central MA. NW winds 8-14 kt gusts
21-28 kt with a decreasing trend to gust speeds thru aftn.

KBOS Terminal...High confidence in TAF/trends, moderate
confidence on wind directions. E to SE winds psbl ~11-16z with
areas LLWS, before wind directions flip to SW ~16-18z.

KBDL Terminal...High confidence in TAF.

Outlook /Wednesday Night through Saturday/...

Wednesday: VFR. Breezy.

Wednesday Night through Thursday: VFR.

Thursday Night: Mainly VFR, with areas MVFR possible. Breezy.
Chance SHRA, chance FZRA.

Friday: Mainly MVFR, with local IFR possible. Windy with local
gusts up to 30 kt. SHRA likely.

Friday Night: Mainly VFR, with local MVFR possible. Windy with
local gusts up to 30 kt. Slight chance SHRA.

Saturday: VFR. Windy with local gusts up to 30 kt.

&&

.MARINE...
Tonight...SW winds 15-20 kt continues along with seas 5-7 ft on
south coastal waters. Dry weather and good vsby.

Tuesday...SW winds 15-20kt gusting to 25 kt ahead of cold
front. Scattered showers likely late in the day across RI
waters.

Tuesday night...SW winds 15-20kt becoming NW 10-15 kts. Seas
7-9 ft on the south waters and 3-5 ft on eastern waters.

Outlook /Wednesday Night through Saturday/...

Wednesday: Winds less than 25 kt. Local rough seas.

Wednesday Night: Winds less than 25 kt. Seas locally
approaching 5 ft.

Thursday: Winds less than 25 kt. Areas of seas approaching
5 ft.

Thursday Night: Winds less than 25 kt. Seas up to 5 ft. Chance
of rain showers.

Friday: Moderate risk for Small Craft Advisory winds with local
gusts up to 30 kt. Areas of rough seas. Chance of rain showers.

Friday Night: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Areas of rough seas. Slight chance of
rain showers.

Saturday: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Areas of rough seas.

&&

.CLIMATE...
Here at the record highs for today...

BOS...77/2016
PVD...70/2016 ** Record high of 72 set today **
BDL...81/2016
ORH...74/2016

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 AM EDT Wednesday for ANZ232>234.
     Small Craft Advisory from 5 PM this afternoon to 2 AM EDT
     Wednesday for ANZ230.
     Small Craft Advisory from 8 AM this morning to 2 AM EDT
     Wednesday for ANZ231-251.
     Small Craft Advisory from 11 AM this morning to 8 AM EDT
     Wednesday for ANZ236.
     Small Craft Advisory until 2 PM EDT Wednesday for ANZ235-237.
     Small Craft Advisory from 8 AM this morning to 2 PM EDT
     Wednesday for ANZ250.
     Small Craft Advisory until 8 PM EDT Wednesday for ANZ254>256.

&&

SYNOPSIS...EVT/BW
NEAR TERM...Loconto/EVT/BW
SHORT TERM...BW
LONG TERM...EVT
AVIATION...Loconto
MARINE...Loconto
CLIMATE...
Hazardous weather outlook, Mar 9, 4:23 PM EDT, 11 hours 57 minutes before
Hazardous Weather Outlook
National Weather Service Boston/Norton MA
423 PM EDT Mon Mar 9 2020

CTZ002>004-MAZ002>024-026-RIZ001>008-102030-
Hartford CT-Tolland CT-Windham CT-Western Franklin MA-
Eastern Franklin MA-Northern Worcester MA-Central Middlesex MA-
Western Essex MA-Eastern Essex MA-Western Hampshire MA-
Western Hampden MA-Eastern Hampshire MA-Eastern Hampden MA-
Southern Worcester MA-Western Norfolk MA-Southeast Middlesex MA-
Suffolk MA-Eastern Norfolk MA-Northern Bristol MA-
Western Plymouth MA-Eastern Plymouth MA-Southern Bristol MA-
Southern Plymouth MA-Barnstable MA-Dukes MA-Nantucket MA-
Northern Middlesex MA-Northwest Providence RI-
Southeast Providence RI-Western Kent RI-Eastern Kent RI-Bristol RI-
Washington RI-Newport RI-Block Island RI-
423 PM EDT Mon Mar 9 2020

This Hazardous Weather Outlook is for northern Connecticut, all of
Massachusetts east of Berkshire County, and Rhode Island.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ230>237-250-251-254>256-102030-
Boston Harbor-Cape Cod Bay-Nantucket Sound-Vineyard Sound-
Buzzards Bay-Rhode Island Sound-Narragansett Bay-Block Island Sound-
Coastal waters east of Ipswich Bay and the Stellwagen Bank National
Marine Sanctuary-Massachusetts Bay and Ipswich Bay-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
Coastal Waters extending out to 25 nm South of Marthas Vineyard and
Nantucket-
Coastal Waters from Montauk NY to Marthas Vineyard extending out to
20 nm South of Block Island-
423 PM EDT Mon Mar 9 2020

This Hazardous Weather Outlook is for Massachusetts and Rhode
Island coastal waters.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

For more information on upcoming hazardous weather, please see the
Area Forecast Discussion on our webpage for the latest forecast
thinking. There is also our Enhanced Hazardous Weather Outlook at
www.weather.gov/box/ehwo

For the latest updates...please visit our webpage at
www.weather.gov/boston

You can follow us on Facebook at
www.facebook.com/us.nationalweatherservice.boston.gov

You can follow us on Twitter at
@NWSBoston

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 10, 4:20 AM EDTCoastal Flood AdvisoryBOXBarnstable11 hr

Nearby

Coastal Flood Statements in Massachusetts, 2020Every coastal flood statement in 2020

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.