Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 78, NWS Boston/Norton, MA

July 23, 20205 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 23, 2020, 4:33 PM EDT for 5 counties in Massachusetts. It was in force for 57 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 23, 2020, 4:33 PM EDT (20:33 UTC)
Expired
Jul 23, 2020, 5:30 PM EDT
In force
57 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Essex County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 45 km from the middle of the area, began a volume at 20:34 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
Jul 23, 4:50 PM EDTTSTM WND DMGBoston, MAPOWER LINES DOWN AT MILTON AVENUE AND ROCKWELL STREET.
Jul 23, 4:50 PM EDTTSTM WND DMGMalden, MATREE DOWN AND BLOCKING FELLSWAY EAST.
Jul 23, 5:05 PM EDTTSTM WND DMG2 Wsw Quincy, MATREE DOWN.
Jul 23, 5:15 PM EDTTSTM WND DMG1 Wsw Winthrop, MAWIRES AND A LARGE BRANCH DOWNED ON COURT ST IN WINTHROP.

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 5 storm reports to this severe thunderstorm warning; the first came 7 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 23, 12:58 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 8.6 hours before the alert went out and 111 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 12:00Z on 2020-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 76 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2020-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 square meters per square second.193958Sfc1 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
76 J/kg
Mixed-layer CIN
-137 J/kg
Mixed-layer LCL
1267 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

510 
WUUS51 KBOX 232033
SVRBOX
MAC009-017-021-023-025-232130-
/O.NEW.KBOX.SV.W.0078.200723T2033Z-200723T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
433 PM EDT Thu Jul 23 2020

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Suffolk County in eastern Massachusetts...
  Northeastern Norfolk County in eastern Massachusetts...
  South central Essex County in northeastern Massachusetts...
  East central Middlesex County in northeastern Massachusetts...
  Northern Plymouth County in southeastern Massachusetts...

* Until 530 PM EDT.

* At 433 PM EDT, a severe thunderstorm was located over Watertown,
  moving east at 30 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* Locations impacted include...
  Boston, Cambridge, Quincy, Lynn, Newton, Somerville, Waltham,
  Malden, Brookline, Medford, Weymouth, Revere, Arlington, Everett,
  Salem, Woburn, Chelsea, Watertown, Lexington and Needham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Hail and damaging winds and continuous cloud to ground lightning is 
occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4246 7094 4242 7091 4245 7097 4236 7097
      4237 7105 4232 7100 4230 7105 4231 7097
      4229 7102 4226 7097 4230 7093 4225 7096
      4225 7088 4233 7093 4234 7088 4226 7087
      4225 7077 4223 7118 4247 7125 4249 7086
TIME...MOT...LOC 2033Z 268DEG 28KT 4237 7121 

HAIL...0.75IN
WIND...60MPH
 
$$

BW
1 follow-up statement
532 
WWUS51 KBOX 232107
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
507 PM EDT Thu Jul 23 2020

MAC009-017-232116-
/O.CAN.KBOX.SV.W.0078.000000T0000Z-200723T2130Z/
Essex MA-Middlesex MA-
507 PM EDT Thu Jul 23 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL ESSEX AND EAST
CENTRAL MIDDLESEX COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
eastern and southeastern Massachusetts.

LAT...LON 4236 7105 4236 7104 4232 7100 4230 7105
      4231 7097 4229 7102 4226 7097 4230 7093
      4225 7096 4225 7088 4233 7093 4234 7088
      4226 7087 4225 7077 4223 7118 4226 7118
TIME...MOT...LOC 2106Z 268DEG 28KT 4238 7086 

$$

MAC021-023-025-232130-
/O.CON.KBOX.SV.W.0078.000000T0000Z-200723T2130Z/
Suffolk MA-Norfolk MA-Plymouth MA-
507 PM EDT Thu Jul 23 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHERN SUFFOLK...NORTHEASTERN NORFOLK AND NORTHERN PLYMOUTH
COUNTIES...

At 506 PM EDT, a severe thunderstorm was located over Hull, or 7
miles southeast of Revere, moving east at 30 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
Boston, Quincy, Weymouth, Milton, Dedham, Hingham, Hull and Cohasset.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4236 7105 4236 7104 4232 7100 4230 7105
      4231 7097 4229 7102 4226 7097 4230 7093
      4225 7096 4225 7088 4233 7093 4234 7088
      4226 7087 4225 7077 4223 7118 4226 7118
TIME...MOT...LOC 2106Z 268DEG 28KT 4238 7086 

HAIL...0.75IN
WIND...60MPH
 
$$

BW

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Jul 23, 2:14 PM EDT, 2 hours 19 minutes earlier.

Area forecast discussion, Jul 23, 2:14 PM EDT, 2 hours 19 minutes before
Area Forecast Discussion
National Weather Service Boston/Norton MA
214 PM EDT Thu Jul 23 2020

.SYNOPSIS...

Scattered thunderstorms will continue into early evening ahead
of an approaching cold front. Some of the storms may produce
damaging winds and torrential rainfall/localized flooding.
Behind the front, not quite as hot or humid Friday along with
mainly dry weather, just a slight chance of an isolated shower
or thunderstorm across CT, RI and southeast MA. High pressure
over New England Saturday provides dry weather and seasonably
warm temperatures. The high moves offshore Sunday and Monday,
circulating hot and humid weather back into the region. A slow
moving cold front will likely result in scattered thunderstorms
Tuesday and Wednesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

210 PM Update...

* Severe Thunderstorm Watch into this evening for the entire
  region except for the Cape/Islands and the south coast of RI

* Localized flood threat exists too

Scattered to numerous thunderstorms have developed across the
northern half of MA at mid afternoon. Despite poor mid level
lapse rates...70 to 75 degree dewpoints have resulted in
surface capes between 2500 and 3000 J/KG. SPC Meso-analysis also
shows bulk effective shear has also increased to between 30 and
35 knots across much of the region, particularly across
northern MA.

As the shortwave and pre-frontal trough continue to press
southeast, scattered thunderstorms should develop further south
towards the Boston to Providence corridor and northern CT
through late afternoon. Despite the poor mid level lapse rates
and marginal shear, plenty of instability will result in some of
the storms becoming strong to severe. Therefore, a Severe
Thunderstorm Watch is in effect through 8 pm this evening for
all but the Cape/Islands and south coast of RI. We do think the
highest severe weather threat is across interior and northern
portions of MA and perhaps into northern CT. Somewhat better
shear/cape overlap exists in this region.

Lastly, given 70 to 75 dewpoints and marginal shear the
strongest thunderstorms will produce torrential rainfall. This
will result in a very localized flash flood threat, particularly
if a cluster of strong t-storms move over a vulnerable urban
center.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...

Tonight...

The threat of severe storms shift south with the cold front but with
the loss of diurnal heating after sunset, severe storms coverage
will likely be more scattered in nature. Storms wind down by the pre-
dawn hours as the cold front clears the South Coast. It will still
remain very mild and muggy, however, with overnight lows in the mid
60s in the interior to low 70s in Eastern MA and RI.

Friday...

* Looks to be a mostly dry day but couldn't rule out afternoon
  thunderstorms, especially towards the S Coast.

By the early morning hours, a positively tilted upper level trough
lifts into Nova Scotia with rising H5 height fields. With light NW
flow aloft, initial signs are that Friday could be a mostly dry day.
The wildcard lies in the uncertainty of how far south the cold front
goes. There are signs that it could stall as a stationary front just
south of the south coast. Moreover, there are also indications of up
to 1000 J/kg of CAPE so have kept at least a slight chance of PoPs
for much of the interior and higher chances south of the MA Pike.
But K indices look to fall sharply behind the cold front from the
30s to the teens and even the single digits in the interior,
indicative of the intrusion of mid-level dry air. With mixing up to
850mb and 850mb temperatures between +13C to +15C, afternoon highs
should top out in the mid 80s. With dew points falling into the
upper 50s to mid 60s, it will feel quite comfortable.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...

323 am update...

Highlights...

* Dry weather Sat, Sun and possibly into Mon then an active
  convective pattern beginning Tue and continuing into at least mid
  week

* Seasonably warm/humid Saturday then possible three day heat wave
  Sunday, Monday and Tuesday

Temperatures...

Low amplitude mean trough over New England briefly erodes northern
periphery of subtropical ridge resulting in seasonable temps and
humidity for late July Fri night and Sat. With 1020 mb high pressure
over the region Friday night, sided with the slightly cooler MOS
guidance. In fact few places across western MA may dip into the
upper 50s! Saturday looks like the pick of the week especially after
a coolish Fri night then dry WNW flow aloft, seasonably warm with
highs in the mid to upper 80s and dew pts in the 60s. By Sunday,
excessive heat and humidity associated with subtropical ridge over
the central U.S. begins to advect eastward with ECENS warming 850 mb
temps to +19C over New England Sunday, then peaking to 20C Monday
before lowering to about +18C by Tuesday as high amplitude trough
enters the Great Lakes. These temps aloft may support a three day
heat wave for many locations in MA/RI/CT Sunday, Monday and Tuesday.
Good model agreement Monday will likely be the hottest day with
probability of 90+ temps between 90-100% and highs likely in the mid
90s. Highs likely fall back into the 80s Wed as approaching high
amplitude trough entering the Great Lakes begins to erode northern
periphery of subtropical ridge.

Precipitation...

Dry WNW flow aloft should yield mainly convective-free weather
Saturday, Sunday and possibly Monday. However by Tue and especially
Wed ECENS continuing to signal a fairly high amplitude trough (at
least by July standards) entering the Great Lakes Tue and edging
closer to New England Wed. This should yield a fairly active
convective pattern for New England beginning Tue and continuing at
least into Wed if not beyond.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...

18z Update...

Forecaster Confidence Levels...

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

This afternoon...High confidence in trends, but lower
confidence in trends. Scattered to numerous thunderstorms have
developed across northern MA. This activity will push southeast
towards the Boston to Providence through 21z-22z. So while VFR
conditions are expected outside the t-storms, IFR-LIFR along
with locally strong winds are expected within thunderstorms.

Tonight...High confidence in trends, but lower confidence in
timing. The scattered thunderstorm threat will end across much
of the region by 02z-03z, but persist a bit longer in parts of
RI/SE MA. Otherwise, VFR conditions dominate but IFR to even
LIFR conditions may develop across the Cape/Islands in lower
clouds and fog. More patchy fog may develop overnight in the
typically prone locations. Winds becoming light overnight.

Friday...High confidence. VFR with any remaining low clouds/fog
burning off during the morning across the Cape/Islands. Isolated
showers possible Fri afternoon mainly towards the south coast,
but the areal coverage will be limited. NE winds 5 to 10 knots.

KBOS Terminal...High confidence in TAF. Scattered thunderstorms
expected between 19z and 23z.

KBDL Terminal...High confidence in TAF. Scattered thunderstorms
expected between 19z and 23z.

Outlook /Saturday through Monday/...

Saturday through Saturday Night: VFR.

Sunday through Sunday Night: VFR. Breezy.

Monday: Mainly VFR, with local MVFR possible. Breezy. Slight
chance SHRA, slight chance TSRA.

&&

.MARINE...
340 AM Update...

Winds and seas remain below Small Craft Advisory criteria through
Friday night. A cold front on Thursday brings the risk for
thunderstorms, some of which may be strong Thursday afternoon
into evening.

Outlook /Saturday through Monday/...

Friday Night: Winds less than 25 kt. Patchy fog.

Saturday through Sunday: Winds less than 25 kt.

Sunday Night through Monday: Winds less than 25 kt. Areas of
seas approaching 5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

SYNOPSIS...Nocera/Chai
NEAR TERM...Frank
SHORT TERM...Chai
LONG TERM...Nocera
AVIATION...Frank/Nocera
MARINE...Nocera/Chai
Hazardous weather outlook, Jul 23, 4:23 PM EDT, 10 minutes before
Hazardous Weather Outlook
National Weather Service Boston/Norton MA
423 PM EDT Thu Jul 23 2020

CTZ003-004-MAZ017>021-RIZ001>004-242030-
Tolland CT-Windham CT-Northern Bristol MA-Western Plymouth MA-
Eastern Plymouth MA-Southern Bristol MA-Southern Plymouth MA-
Northwest Providence RI-Southeast Providence RI-Western Kent RI-
Eastern Kent RI-
423 PM EDT Thu Jul 23 2020

...SEVERE THUNDERSTORM WATCH 395 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for northern Connecticut,
southeastern Massachusetts and northern Rhode Island.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

MAZ022>024-RIZ005>008-242030-
Barnstable MA-Dukes MA-Nantucket MA-Bristol RI-Washington RI-
Newport RI-Block Island RI-
423 PM EDT Thu Jul 23 2020

This Hazardous Weather Outlook is for southeastern Massachusetts,
northern Rhode Island and southern Rhode Island.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ231>237-250-254>256-242030-
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-
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 Thu Jul 23 2020

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

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ230-251-242030-
Boston Harbor-Massachusetts Bay and Ipswich Bay-
423 PM EDT Thu Jul 23 2020

...SEVERE THUNDERSTORM WATCH 395 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for Massachusetts coastal waters.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

CTZ002-MAZ002>016-026-242030-
Hartford 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 Middlesex MA-
423 PM EDT Thu Jul 23 2020

...SEVERE THUNDERSTORM WATCH 395 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for northern Connecticut, central
Massachusetts, eastern Massachusetts, northeastern Massachusetts
and western Massachusetts.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

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

In the hours before

Special weather statement, Jul 23, 3:10 PM EDT, 1 hour 23 minutes before
Special Weather Statement
National Weather Service Boston/Norton MA
310 PM EDT Thu Jul 23 2020

CTZ002-MAZ009-011-232000-
Hartford CT-Western Hampden MA-Eastern Hampden MA-
310 PM EDT Thu Jul 23 2020

...STRONG THUNDERSTORM MOVING INTO WESTERN HARTFORD AND HAMPDEN
COUNTIES...

At 310 PM EDT, Doppler radar was tracking a strong thunderstorm near
Tolland, or 13 miles north of Torrington, moving southeast at 25 mph.

Pea size hail and wind gusts up to 50 mph will accompany this storm.

Locations impacted include...
Hartford, West Hartford, Enfield, Windsor, Simsbury, Bloomfield,
Avon, Suffield, Windsor Locks, Granby, East Windsor, Canton,
Southwick, East Granby, Hartland, Granville and Tolland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when this storm approaches. Winds may be strong enough to
produce minor damage, such as a few downed branches.

Do not drive through flooded roads or underpasses. Avoid low lying
areas near small streams.

&&

LAT...LON 4213 7306 4199 7254 4175 7269 4186 7295
      4189 7294 4190 7291 4197 7289 4197 7303
      4204 7301 4204 7306 4206 7305 4211 7307
TIME...MOT...LOC 1910Z 294DEG 23KT 4203 7308

BW
Special weather statement, Jul 23, 3:47 PM EDT, 46 minutes before
Special Weather Statement
National Weather Service Boston/Norton MA
347 PM EDT Thu Jul 23 2020

MAZ005>007-014-232030-
Eastern Essex MA-Central Middlesex County MA-Western Essex MA-
Southeast Middlesex MA-
347 PM EDT Thu Jul 23 2020

...STRONG THUNDERSTORM OVER CENTRAL ESSEX COUNTY...

At 346 PM EDT, Doppler radar was tracking a strong thunderstorm over
Middleton, or near Danvers, moving east at 35 mph.

Winds in excess of 40 mph will accompany this storm.

Locations impacted include...
Lynn, Lawrence, Peabody, Salem, Billerica, Beverly, Woburn, Andover,
Dracut, Tewksbury, Gloucester, North Andover, Danvers, Wakefield,
Reading, Burlington, Wilmington, Stoneham, Marblehead and North
Reading.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when this storm approaches. Winds may be strong enough to
produce minor damage, such as a few downed branches.

&&

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
northeastern Massachusetts.

LAT...LON 4267 7073 4264 7076 4269 7063 4265 7059
      4258 7066 4259 7066 4260 7065 4261 7066
      4253 7078 4256 7078 4254 7090 4253 7089
      4251 7085 4251 7095 4249 7123 4267 7126
      4274 7082 4270 7083 4275 7079
TIME...MOT...LOC 1946Z 261DEG 32KT 4261 7102

BL
Special weather statement, Jul 23, 4:04 PM EDT, 29 minutes before
Special Weather Statement
National Weather Service Boston/Norton MA
404 PM EDT Thu Jul 23 2020

CTZ002-003-232045-
Hartford CT-Tolland CT-
404 PM EDT Thu Jul 23 2020

...STRONG THUNDERSTORM OVER NORTHERN HARTFORD COUNTY...

At 404 PM EDT, Doppler radar was tracking a strong thunderstorm over
East Granby, or near Windsor, moving east at 25 mph.

Winds in excess of 40 mph will accompany this storm.

Locations impacted include...
Hartford, West Hartford, Manchester, East Hartford, Enfield,
Glastonbury, Vernon, Windsor, Mansfield, South Windsor, Simsbury,
Bloomfield, Avon, Suffield, Ellington, Tolland, Windsor Locks,
Coventry, Stafford and Somers.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when this storm approaches. Winds may be strong enough to
produce minor damage, such as a few downed branches.

&&

LAT...LON 4203 7273 4191 7222 4163 7238 4188 7295
TIME...MOT...LOC 2003Z 289DEG 22KT 4192 7273

BL
Special weather statement, Jul 23, 4:05 PM EDT, 28 minutes before
Special Weather Statement
National Weather Service Boston/Norton MA
405 PM EDT Thu Jul 23 2020

MAZ004-005-012>014-232045-
Southern Worcester MA-Western Norfolk MA-Central Middlesex County MA-
Northern Worcester MA-Southeast Middlesex MA-
405 PM EDT Thu Jul 23 2020

...STRONG THUNDERSTORM...

At 404 PM EDT, Doppler radar was tracking a strong thunderstorm over
Northborough, or near Marlborough, moving east at 25 mph.

Pea size hail and winds in excess of 40 mph will accompany this
storm.

Locations impacted include...
Newton, Framingham, Waltham, Billerica, Marlborough, Shrewsbury,
Natick, Lexington, Needham, Wellesley, Acton, Hudson, Westborough,
Grafton, Concord, Sudbury, Ashland, Hopkinton, Northborough and
Clinton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when this storm approaches. Winds may be strong enough to
produce minor damage, such as a few downed branches.

Do not drive through flooded roads or underpasses. Avoid low lying
areas near small streams.

Frequent lightning was occurring. Lightning can strike far away from
the storm. Go inside a building or vehicle. Wait at least 30 minutes
until after the storm has passed to resume outdoor activities.

&&

LAT...LON 4254 7126 4228 7120 4223 7166 4241 7171
TIME...MOT...LOC 2004Z 260DEG 23KT 4234 7161

BW
Local storm report, Jul 23, 4:25 PM EDT, 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TAUNTON MA
425 PM EDT THU JUL 23 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0238 PM     FLOOD            DEERFIELD               42.55N 72.60W
07/23/2020                   FRANKLIN           MA   AMATEUR RADIO

            FLOODING WAIST-DEEP ON SOUTH RIVER STREET.

0240 PM     TSTM WND DMG     GRANBY                  42.26N 72.53W
07/23/2020                   HAMPSHIRE          MA   AMATEUR RADIO

            HARRIS STREET AND SURROUNDING STREETS HAVE SEVERAL TREES
            AND LARGE LIMBS DOWN.

0252 PM     TSTM WND DMG     BELCHERTOWN             42.27N 72.40W
07/23/2020                   HAMPSHIRE          MA   AMATEUR RADIO

            TREE DOWN BLOCKING WARREN WRIGHT ROAD.

0252 PM     TSTM WND DMG     BELCHERTOWN             42.27N 72.40W
07/23/2020                   HAMPSHIRE          MA   AMATEUR RADIO

            ONE LARGE TREE AND ONE LARGE TREE BRANCH DOWN ON WIRES ON
            GEORGE HANNUM ROAD. TREE DOWN BLOCKING BAY ROAD. LARGE
            TREE DOWN ON WIRES ON HAMILTON STREET.

0303 PM     FLOOD            METHUEN                 42.72N 71.18W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            LOWELL STREET IMPASSABLE DUE TO FLOOD WATERS. TWO CARS
            TRAPPED.

0308 PM     FLOOD            LAWRENCE                42.70N 71.16W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            EAST HAVERHILL STREET AT BERKLEY STREET, SHERIDAN STREET
            AT BERKLEY, BERKLEY STREET AT JACKSON STREET ARE ALL
            FLOODED AND IMPASSABLE.

0308 PM     FLOOD            METHUEN                 42.72N 71.18W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            BROADWAY AT NEVINS MANOR IS FLOODED AND IMPASSABLE.

0310 PM     TSTM WND DMG     ANDOVER                 42.66N 71.14W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            TREE DOWN ON WIRES ON CHANDLER ROAD. TREE DOWN ON WIRES
            ON GREENWOOD ROAD.

0310 PM     TSTM WND DMG     NORTH READING           42.57N 71.07W
07/23/2020                   MIDDLESEX          MA   AMATEUR RADIO

            TREE DOWN BLOCKING LOWELL ROAD

0312 PM     FLOOD            LAWRENCE                42.70N 71.16W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            PARKER STREET CLOSED AT THE BRIDGE DUE TO FLOODING.

0313 PM     FLOOD            METHUEN                 42.72N 71.18W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            STATE ROUTE 110 AT OAK STREET FLOODED AND IMPASSABLE.

0315 PM     TSTM WND DMG     BEVERLY                 42.56N 70.84W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            TREE DOWN ON ESSEX STREET AND PARTIALLY BLOCKING THE
            ROAD.

0315 PM     TSTM WND DMG     AMESBURY                42.86N 70.93W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            TREE DOWN ON PLEASANT VALLEY ROAD

0320 PM     FLOOD            GEORGETOWN              41.26N 73.43W
07/23/2020                   FAIRFIELD          CT   AMATEUR RADIO

            WEST MAIN STREET AND SEVERAL OTHER STREETS FLOODED AND
            IMPASSABLE.

0322 PM     FLOOD            METHUEN                 42.72N 71.18W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            JACKSON STREET FLOODED AND IMPASSABLE.

0326 PM     FLOOD            NEWBURYPORT             42.81N 70.89W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            WATER STREET AT FEDERAL STREET FLOODED AND IMPASSABLE.
            ONE CAR TRAPPED IN THE FLOODING.

0337 PM     TSTM WND DMG     PRINCETON               42.45N 71.87W
07/23/2020                   WORCESTER          MA   AMATEUR RADIO

            TREE DOWN ON MOUNTAIN ROAD.

0342 PM     FLOOD            BEVERLY                 42.56N 70.84W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            RIVER STREET FLOODED. TWO CARS TRAPPED.

0342 PM     FLOOD            NEWBURYPORT             42.81N 70.89W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            SIX INCHES OF STREET FLOODING ON PLUM ISLAND TURNPIKE.

0345 PM     FLOOD            ANDOVER                 41.73N 72.37W
07/23/2020                   TOLLAND            CT   AMATEUR RADIO

            LOWELL STREET AND STATE ROUTE 113 EASTBOUND FLOODED.

0346 PM     FLOOD            BEVERLY                 42.56N 70.84W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            CABOT STREET FROM MILTON STREET TO CHURCH STREET FLOODED
            AND IMPASSABLE.

0410 PM     FLOOD            GLOUCESTER              42.62N 70.65W
07/23/2020                   ESSEX              MA   AMATEUR RADIO

            MAPLEWOOD AVENUE FLOODED AND IMPASSABLE.

&&

WTB
Special weather statement, Jul 23, 4:27 PM EDT, 6 minutes before
Special Weather Statement
National Weather Service Boston/Norton MA
427 PM EDT Thu Jul 23 2020

CTZ004-MAZ012-013-RIZ001-232100-
Windham CT-Southern Worcester MA-Western Norfolk MA-
Northwest Providence RI-
427 PM EDT Thu Jul 23 2020

...STRONG THUNDERSTORM...

At 427 PM EDT, Doppler radar was tracking a strong thunderstorm over
Webster, or 16 miles south of Worcester, moving east at 25 mph.

Wind gusts up to 50 mph will accompany this storm.

Locations impacted include...
Woonsocket, Smithfield, Webster, Bellingham, Burrillville,
Northbridge, Oxford, Uxbridge, Charlton, North Smithfield, Dudley,
Glocester, Putnam, Thompson, Blackstone, Sutton, Douglas, Woodstock,
Hopedale and Mendon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when this storm approaches. Winds may be strong enough to
produce minor damage, such as a few downed branches.

Do not drive through flooded roads or underpasses. Avoid low lying
areas near small streams.

Frequent lightning was occurring. Lightning can strike far away from
the storm. Go inside a building or vehicle. Wait at least 30 minutes
until after the storm has passed to resume outdoor activities.

&&

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
northern Connecticut...eastern and central Massachusetts...and Rhode
Island.

LAT...LON 4194 7200 4211 7193 4212 7148 4190 7153
TIME...MOT...LOC 2027Z 280DEG 22KT 4204 7188

BL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 8:12 PM EDTSpecial Weather StatementBOXHampshire48 min
Jul 23, 1:33 PM EDTSpecial Weather StatementBOXFranklin42 min
Jul 23, 1:45 PM EDTSpecial Weather StatementBOXEssex30 min
Jul 23, 1:51 PM EDTSpecial Weather StatementBOXHampshire54 min
Jul 23, 1:59 PM EDTSevere Thunderstorm WarningBOXEssex23 min
Jul 23, 2:10 PM EDTSpecial Weather StatementBOXMiddlesex50 min
Jul 23, 2:15 PM EDTSpecial Weather StatementBOXHampshire45 min
Jul 23, 2:16 PM EDTSpecial Marine WarningBOX59 min
Jul 23, 2:21 PM EDTSpecial Marine WarningBOX54 min
Jul 23, 2:33 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester43 min
Jul 23, 2:33 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester45 min
Jul 23, 2:37 PM EDTSpecial Marine WarningBOX53 min
Jul 23, 2:39 PM EDTSevere Thunderstorm WarningBOXFranklin, Middlesex, Worcester39 min
Jul 23, 2:48 PM EDTSpecial Weather StatementBOXEssex57 min
Jul 23, 3:01 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex37 min
Jul 23, 3:03 PM EDTFlash Flood WarningBOXEssex72 min
Jul 23, 3:09 PM EDTSpecial Marine WarningBOX66 min
Jul 23, 3:20 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester55 min
Jul 23, 3:33 PM EDTSpecial Marine WarningBOX57 min
Jul 23, 3:47 PM EDTSpecial Weather StatementBOXEssex43 min
Jul 23, 4:05 PM EDTSpecial Weather StatementBOXMiddlesex40 min
Jul 23, 4:19 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester56 min
Jul 23, 4:32 PM EDTSpecial Marine WarningBOX58 min
Jul 23, 4:35 PM EDTAreal Flood WarningBOXEssex, Middlesex, Norfolk, Plymouth, Suffolk48 min
Jul 23, 4:38 PM EDTSevere Thunderstorm WarningBOXBristol, Norfolk, Plymouth, Worcester67 min
Jul 23, 4:45 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Plymouth, Suffolk60 min
Jul 23, 4:50 PM EDTSpecial Marine WarningBOX55 min
Jul 23, 5:29 PM EDTSpecial Marine WarningBOX61 min
Jul 23, 6:03 PM EDTSpecial Weather StatementBOXHampden27 min
Jul 23, 6:07 PM EDTSpecial Weather StatementBOXPlymouth23 min
Jul 23, 6:28 PM EDTSpecial Marine WarningBOX62 min
Jul 23, 6:30 PM EDTSpecial Marine WarningBOX60 min
Jul 23, 6:34 PM EDTSevere Thunderstorm WarningBOXBarnstable, Plymouth41 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2020Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.