Alert archive / Massachusetts / Winter Storm Warnings in 2021

Winter Storm Warning 4, NWS Boston/Norton, MA

February 9, 20216 counties in Massachusetts

NWS Boston/Norton, MA issued this winter storm warning at Feb 9, 2021, 1:59 AM EST for 6 counties in Massachusetts. It took effect at Feb 9, 2021, 4:00 AM EST. It was in force for 10 hr. 16 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Feb 9, 2021, 1:59 AM EST (06:59 UTC)
In effect from
Feb 9, 2021, 4:00 AM EST
Expired
Feb 9, 2021, 1:48 PM EST
In force
10 hr
Issued by
NWS Boston/Norton, MA

Counties Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 89 km from the middle of the area, began a volume at 07:03 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.

What was reported inside it

TimeReportWhereRemark
Feb 9, 10:46 AM ESTSNOW 1Longmeadow, MA
Feb 9, 12:20 PM ESTSNOW 1.5Russell, MA
Feb 9, 12:38 PM ESTSNOW 1.2Hampden, MA
Feb 9, 12:48 PM ESTSNOW 1North Grafton, MA
Feb 9, 12:59 PM ESTSNOW 1Holden, MA
Feb 9, 1:00 PM ESTSNOW 1Holden, MA
Feb 9, 1:00 PM ESTSNOW 1.9Springfield, MAINDIAN ORCHARD
Feb 9, 1:08 PM ESTSNOW 1.9Springfield, MA
Feb 9, 1:16 PM ESTSNOW 1.3Auburn, MA
Feb 9, 1:25 PM ESTSNOW 1.2Northbridge, MA
Feb 9, 1:30 PM ESTSNOW 1.3Northborough, MA
Feb 9, 1:35 PM ESTSNOW 1.3Northborough, MA
Feb 9, 1:35 PM ESTSNOW 1.6South Acton, MA
Feb 9, 1:44 PM ESTSNOW 1.3Leominster, MA
Feb 9, 1:48 PM ESTSNOW 1Cambridge, MA
Feb 9, 1:56 PM ESTSNOW 1.4Lexington, MA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 7.0 hours before the alert went out and 152 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, Albany, NY at 00:00Z on 2021-02-09Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 00:00Z on 2021-02-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 square meters per square second.1939587897117136Sfc1 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
1506 m above ground
0-6 km bulk shear
116 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

455 
WWUS41 KBOX 090659
WSWBOX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Boston/Norton MA
159 AM EST Tue Feb 9 2021

MAZ002>012-014-026-091700-
/O.UPG.KBOX.WW.Y.0009.210209T0900Z-210210T0300Z/
/O.NEW.KBOX.WS.W.0004.210209T0900Z-210210T0300Z/
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-Southeast Middlesex MA-
Northern Middlesex MA-
Including the cities of Charlemont, Greenfield, Orange, Barre, 
Fitchburg, Framingham, Lowell, Lawrence, Gloucester, 
Chesterfield, Blandford, Amherst, Northampton, Springfield, 
Milford, Worcester, Cambridge, and Ayer
159 AM EST Tue Feb 9 2021

...WINTER STORM WARNING IN EFFECT UNTIL 10 PM EST THIS EVENING...

* WHAT...Heavy snow expected. Total snow accumulations of 5 to 7 
  inches.

* WHERE...Western and Central Massachusetts, the Merrimack Valley
  and North Shore in Massachusetts.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute. The
  worst conditions are expected with the evening commute.

* ADDITIONAL DETAILS...Snowfall rates up to 1 inch per hour at 
  times with reduced visibilities are expected to develop by mid- 
  afternoon. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

&&

$$

MAZ017>019-RIZ003>005-091700-
/O.EXA.KBOX.WW.Y.0009.210209T0900Z-210210T0300Z/
Northern Bristol MA-Western Plymouth MA-Eastern Plymouth MA-
Western Kent RI-Eastern Kent RI-Bristol RI-
Including the cities of Taunton, Brockton, Plymouth, Coventry, 
West Greenwich, East Greenwich, Warwick, West Warwick, 
and Bristol
159 AM EST Tue Feb 9 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 PM EST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 
  inches.

* WHERE...Much of southeastern Massachusetts and central Rhode 
  Island.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the morning or evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

&&

$$

CTZ002>004-MAZ013-015-016-RIZ001-002-091700-
/O.CON.KBOX.WW.Y.0009.210209T0900Z-210210T0300Z/
Hartford CT-Tolland CT-Windham CT-Western Norfolk MA-Suffolk MA-
Eastern Norfolk MA-Northwest Providence RI-
Southeast Providence RI-
Including the cities of Hartford, Windsor Locks, Union, Vernon, 
Putnam, Willimantic, Foxborough, Norwood, Boston, Quincy, Foster,
Smithfield, and Providence
159 AM EST Tue Feb 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM EST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 3 to 5 
  inches.

* WHERE...Northern Connecticut, Northern Rhode Island into Norfolk
  and Suffolk Counties in Massachusetts.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning or evening commute. The
  worst conditions are expected during the evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

&&

$$

Loconto
2 follow-up statements
723 
WWUS41 KBOX 091632
WSWBOX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Boston/Norton MA
1132 AM EST Tue Feb 9 2021

MAZ002>012-014-026-100045-
/O.CON.KBOX.WS.W.0004.000000T0000Z-210210T0300Z/
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-Southeast Middlesex MA-
Northern Middlesex MA-
Including the cities of Charlemont, Greenfield, Orange, Barre, 
Fitchburg, Framingham, Lowell, Lawrence, Gloucester, 
Chesterfield, Blandford, Amherst, Northampton, Springfield, 
Milford, Worcester, Cambridge, and Ayer
1132 AM EST Tue Feb 9 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 PM EST THIS
EVENING...

* WHAT...Heavy snow expected. Total snow accumulations of 3 to 6 
  inches.

* WHERE...Western and Central Massachusetts, the Merrimack 
  Valley and North Shore in Massachusetts.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Travel could be very difficult. The hazardous 
  conditions could impact the morning or evening commute. The 
  worst conditions are expected with the evening commute.

* ADDITIONAL DETAILS...Snowfall rates up to 1 inch per hour at 
  times with reduced visibilities are expected to develop by mid-
   afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

&&

$$

CTZ002>004-MAZ013-015>019-RIZ001>005-100045-
/O.CON.KBOX.WW.Y.0009.000000T0000Z-210210T0300Z/
Hartford CT-Tolland CT-Windham CT-Western Norfolk MA-Suffolk MA-
Eastern Norfolk MA-Northern Bristol MA-Western Plymouth MA-
Eastern Plymouth MA-Northwest Providence RI-
Southeast Providence RI-Western Kent RI-Eastern Kent RI-
Bristol RI-
Including the cities of Hartford, Windsor Locks, Union, Vernon, 
Putnam, Willimantic, Foxborough, Norwood, Boston, Quincy, 
Taunton, Brockton, Plymouth, Foster, Smithfield, Providence, 
Coventry, West Greenwich, East Greenwich, Warwick, West Warwick, 
and Bristol
1132 AM EST Tue Feb 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM EST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 
  inches.

* WHERE...Much of southeastern Massachusetts and central Rhode 
  Island.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning or evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

&&

$$
302 
WWUS41 KBOX 091848
WSWBOX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Boston/Norton MA
148 PM EST Tue Feb 9 2021

MAZ002>012-014-026-100300-
/O.CAN.KBOX.WS.W.0004.000000T0000Z-210210T0300Z/
/O.EXA.KBOX.WW.Y.0009.000000T0000Z-210210T0300Z/
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-Southeast Middlesex MA-
Northern Middlesex MA-
Including the cities of Charlemont, Greenfield, Orange, Barre, 
Fitchburg, Framingham, Lowell, Lawrence, Gloucester, 
Chesterfield, Blandford, Amherst, Northampton, Springfield, 
Milford, Worcester, Cambridge, and Ayer
148 PM EST Tue Feb 9 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 PM EST THIS
EVENING...
...WINTER STORM WARNING IS CANCELLED...

* WHAT...Snow. Additional snow accumulations of up to two inches.

* WHERE...Portions of central, eastern, northeastern and western 
  Massachusetts.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the morning or evening commute.

* ADDITIONAL DETAILS...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

&&

$$

CTZ002>004-MAZ013-015>019-RIZ001>005-100300-
/O.CON.KBOX.WW.Y.0009.000000T0000Z-210210T0300Z/
Hartford CT-Tolland CT-Windham CT-Western Norfolk MA-Suffolk MA-
Eastern Norfolk MA-Northern Bristol MA-Western Plymouth MA-
Eastern Plymouth MA-Northwest Providence RI-
Southeast Providence RI-Western Kent RI-Eastern Kent RI-
Bristol RI-
Including the cities of Hartford, Windsor Locks, Union, Vernon, 
Putnam, Willimantic, Foxborough, Norwood, Boston, Quincy, 
Taunton, Brockton, Plymouth, Foster, Smithfield, Providence, 
Coventry, West Greenwich, East Greenwich, Warwick, West Warwick, 
and Bristol
148 PM EST Tue Feb 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM EST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 
  inches.

* WHERE...Much of southeastern Massachusetts and central Rhode 
  Island.

* WHEN...Until 10 PM EST this evening.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the morning or evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 9, 3:07 PM ESTSmall Craft AdvisoryBOX19 hr

Nearby

Winter Storm Warnings in Massachusetts, 2021Every winter storm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.