Severe Thunderstorm Warning 8, NWS Boston/Norton, MA

141 
WWUS51 KBOX 142315
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
715 PM EDT Wed Jun 14 2023

RIC005-142324-
/O.CAN.KBOX.SV.W.0008.000000T0000Z-230614T2345Z/
Newport RI-
715 PM EDT Wed Jun 14 2023

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL NEWPORT COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4149 7106 4165 7108 4187 7079 4168 7072
      4170 7073 4172 7075 4164 7077 4166 7082
      4163 7087 4158 7082 4165 7092 4159 7090
      4161 7091 4161 7092 4160 7092 4160 7096
      4152 7095 4152 7096 4153 7096 4149 7104
TIME...MOT...LOC 2314Z 222DEG 23KT 4170 7091 

$$

MAC005-023-142345-
/O.CON.KBOX.SV.W.0008.000000T0000Z-230614T2345Z/
Plymouth MA-Bristol MA-
715 PM EDT Wed Jun 14 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SOUTH CENTRAL PLYMOUTH AND SOUTHEASTERN BRISTOL COUNTIES...

At 714 PM EDT, a severe thunderstorm was located over Acushnet, or
over New Bedford, moving northeast at 25 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect wind damage to trees and power lines. Minor hail 
         damage to vehicles is possible.

Locations impacted include...
New Bedford, Dartmouth, Marion, Middleborough, Wareham, Fairhaven,
Westport, Carver, Acushnet, Freetown, Mattapoisett and Rochester.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4149 7106 4165 7108 4187 7079 4168 7072
      4170 7073 4172 7075 4164 7077 4166 7082
      4163 7087 4158 7082 4165 7092 4159 7090
      4161 7091 4161 7092 4160 7092 4160 7096
      4152 7095 4152 7096 4153 7096 4149 7104
TIME...MOT...LOC 2314Z 222DEG 23KT 4170 7091 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Frank

413 
WWUS51 KBOX 142340
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
740 PM EDT Wed Jun 14 2023

MAC005-023-142350-
/O.EXP.KBOX.SV.W.0008.000000T0000Z-230614T2345Z/
Plymouth MA-Bristol MA-
740 PM EDT Wed Jun 14 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL PLYMOUTH AND
SOUTHEASTERN BRISTOL COUNTIES WILL EXPIRE AT 745 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 4149 7106 4165 7108 4187 7079 4168 7072
      4170 7073 4172 7075 4164 7077 4166 7082
      4163 7087 4158 7082 4165 7092 4159 7090
      4161 7091 4161 7092 4160 7092 4160 7096
      4152 7095 4152 7096 4153 7096 4149 7104
TIME...MOT...LOC 2340Z 238DEG 24KT 4179 7072 

$$

Frank

Area Forecast Discussion
National Weather Service Boston/Norton MA
220 PM EDT Wed Jun 14 2023

.SYNOPSIS...

Scattered showers and thunderstorms moving through southern New
England this afternoon and evening. A few strong to severe
thunderstorms are possible with the main threats of hail and
damaging wind gusts. Our pattern remains unsettled later this
week into early next week, with scattered showers and
thunderstorms. Temperatures will be near to slightly below
normal.

&&

.NEAR TERM /UNTIL 6 AM Thursday/...

Highlights

* Strong to severe thunderstorms possible across southern New
  England. Main threats are large hail and damaging wind gusts.

A cutoff low is initially located over northern PA/central NY
early this afternoon. The cutoff will rotate eastward into
southern New England this evening. The cutoff will lift into
Maine by early Thu. Low pressure will rotate into southern New
England tonight and the cold front associated with it will
slides through the south coast by late tonight. The surface low
will lift into the Gulf of Maine by early Thu.

Main concern in the forecast is the strong to severe
thunderstorm risk across southern New England as we head into
the evening. At this point am leaning toward the ARW and NSSL
WRF guidance as it has pegged current storm activity fairly well
along with the synoptic scale features. Will first start off
with the limiting factor with the activity at the moment is the
effective deep layer shear is somewhat marginal with SPC
Mesoanalysis showing 20-30 kts. This is anticipated to increase
especially across the south coast as the mid level jet pushes in
as the cutoff lifts into our area. The effective shear should
increase to around 40 kts across the south coast. This will
combine with sfc based CAPE values of roughly 500-1500 J/kg with
the highest values across the south coast. As we head into the
evening the instability will wane, but mid level lapse rates
will be increasing. This may be enough to keep activity together
as it moves into an increasing stable airmass. Low level lapse
rates are around 7-9 degrees Celsius per km before they diminish
this evening, while mid level lapse rates increase to 6-8
degrees Celsius as the upper low is moving in, which is also
when we will see 500 temps cooling to -15 to -20 degrees
Celsius. Looks like the best shot for the 60+ degree dew points
is also across the south coast per the latest HREF, which is
doing well based on the latest observations. There is more than
sufficient CAPE within the hail growth zone and given the cooler
air moving in aloft am expecting there to be a risk of large
hail and gusty winds as the scattered storms move through. As
previously mentioned there is a bit of backing across the CT
Valley as the LLJ is increasing and winds backing. This is
progged well by 100+ m2/s2 across the CT Valley late this
afternoon along with low LCL heights, so there is a low risk of
a tornado as indicated by the HREF.

The latest NCAR HRRR Neural Network guidance falls in line with
current severe timing thinking of roughly 21-01Z as the deep
layer shear is increasing with the highest probs across the
south coast. This matches well the SPC SREF Craven Brooks Sig
Svr greater than 10k highest probs and HRRR SCRAM values. Cannot
completely rule out stronger storms further to the north,
across MA. At this point the deep layer shear/instability
overlap is across the south coast, so will need to keep an eye
on things. Should see the activity diminish as instability wanes
tonight. After 9 PM think that there still could be a few
lingering showers with the low lifting through into early Thu.

Will see high temps top out in the mid 70s to low 80s across the
region today. Tonight low temps bottom out in the 50s.

&&

.SHORT TERM /THURSDAY/...

Highlights

* Generally dry, but there could be a few spot showers across
  the interior.

Caught under cyclonic flow through this period. A shortwave
ridge will build across the eastern Great Lakes into New
England. A shortwave may still rotate through northern New
England toward southern New England by the afternoon. A surface
trough will be over the region during this period.

Main focus of the forecast was on the near term period, but
given the shortwave digging toward the region during the
afternoon there could be a few spot showers. Am not overly
confident in this risk as the mid levels will be drying. As a
result have dialed back precip chances and honestly think for
most it will be dry, but there could be a few spot showers.

Expecting some downsloping as flow aloft shifts to the W/NW.
Will see temperatures warming at 925 hPa to 15 to 20 degrees
Celsius. Bumped temps up to the 75th percentile of guidance,
which results in highs ranging from the low 70s to the low 80s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

1140 AM Update:

Key Points:
 * Wet weather pattern with near or slightly below normal temps
 * Low risk of severe weather Saturday

Amplified and blocky upper air pattern is expected to persist into
next week per ensembles. Building upper ridge over northern Plains
will help another cutoff low form over eastern Great Lakes by end of
week which meanders over New England this weekend. By the middle of
next week, there are signs that Rex block pattern may take shape as
upper ridge becomes more W-E oriented from Great Lakes to Northeast
and a closed low develops near TN Valley.

This all means a continuation of near to slightly below normal
temperatures through the middle of next week along with scattered
showers or thunderstorms at times.

Main concern is potential for severe weather Saturday - right now
it's a low risk but something to monitor in coming days. Ensembles
show decent probabilities of 1000-1500 J/kg of CAPE along with
fairly steep lapse rates (given presence of cold pool aloft
associated with cutoff low) but shear is relatively weak. However,
in these situations we can often see higher CAPE values compensate
for lack of deep shear. Colorado State Machine Learning probs also
have low probabilities centered over southern New England.

&&

.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...

Forecaster
Confidence Levels:

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

Overall high confidence through Wednesday. Scattered showers and
thunderstorms with localized MVFR/IFR develop in western New
England after 18z and should reach coastal terminals closer to
22-23z, outside of cape Cod and Islands where storms are not
expected. Most TAF sites have TS for a 2-3 hour window. S/SW
winds 10-15kt with coastal sea breezes, although winds along
coast should turn S later in day.

Scattered showers/storms end this evening followed by lower-end
VFR or MVFR cigs tonight and possibly into Thu. S/SW winds
5-10kt shift to W overnight and Thu.

KBOS Terminal...Moderate confidence in TAF. E wind should shift
to S around 21-22z. Fairly confident that window for TS is
23z-01z.

KBDL Terminal...High confidence in TAF. Fairly confident on TS
timing from 18z-21z.

Outlook /Thursday Night through Sunday/...

Thursday Night: VFR.

Friday: VFR. Chance SHRA, chance TSRA.

Friday Night: Mainly VFR, with local IFR possible. SHRA likely,
slight chance TSRA.

Saturday: MVFR/IFR conditions possible. SHRA likely, chance
TSRA.

Saturday Night: Mainly VFR, with local IFR possible. Chance
SHRA, slight chance TSRA.

Sunday: Mainly VFR, with local IFR possible. Chance SHRA.

&&

.MARINE...

Forecaster Confidence Levels:

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

Through Tonight...High confidence.

Scattered showers with isolated thunderstorms late this
afternoon into the evening. Any stronger storms may produce
strong to damaging wind gusts, large hail, reduced visibility
and rough seas. Late tonight there may still be a few lingering
showers. Winds out of the S at 10-15 kts with gusts up to 20
kts. Tonight winds will shift to the SW at 10-20 kts and gusts
of 15-20 kts. There may be a few gusts to 25 kts across the
southern waters late. Seas 2-4 ft, but portions of the southern
outer waters may approach 5 ft. Given the marginal nature am
holding off on a SCA.

Thursday...High confidence.

Dry with winds SW 10-15 kts gusting to 20 kts over the southern waters.
Seas 2-4 ft.

Outlook /Thursday Night through Sunday/...

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

Friday: Winds less than 25 kt. Chance of rain showers.

Friday Night through Saturday: Winds less than 25 kt. Rain
showers likely, isolated thunderstorms.

Saturday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers.

Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers.

&&

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

&&

SYNOPSIS...BL/JWD
NEAR TERM...BL
SHORT TERM...BL
LONG TERM...JWD
AVIATION...JWD
MARINE...BL/JWD

Hazardous Weather Outlook
National Weather Service Boston/Norton MA
409 PM EDT Wed Jun 14 2023

CTZ002>004-MAZ002>024-026-RIZ001>008-152015-
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-
409 PM EDT Wed Jun 14 2023

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...Thursday through Tuesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ230>237-250-251-254>256-152015-
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-
409 PM EDT Wed Jun 14 2023

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...Thursday through Tuesday.

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/NWSBoston

You can follow us on Twitter at
@NWSBoston

Preliminary Local Storm Report
National Weather Service Boston/Norton MA
504 PM EDT Wed Jun 14 2023

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

0419 PM     Tstm Wnd Dmg     1 S Gill                42.64N 72.50W
06/14/2023                   Franklin           MA   Fire Dept/Rescue

            Tree knocked down on Main Road. Time
            estimated from radar.

0430 PM     Tstm Wnd Dmg     1 SSE Northfield        42.70N 72.43W
06/14/2023                   Franklin           MA   Fire Dept/Rescue

            Trees knocked down on Warwick and
            Strowbridge Roads in Northfield. Time
            estimated by radar.

&&

Special Weather Statement
National Weather Service Boston/Norton MA
532 PM EDT Wed Jun 14 2023

MAZ004-005-012-026-142215-
Northwest Middlesex County MA-Southern Worcester MA-
Central Middlesex County MA-Northern Worcester MA-
532 PM EDT Wed Jun 14 2023

...A strong thunderstorm will impact portions of northeastern
Worcester and northwestern Middlesex Counties through 615 PM EDT...

At 532 PM EDT, Doppler radar was tracking a strong thunderstorm over
Sterling, or near Leominster, moving north at 25 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Strong winds could cause minor damage such as downed
         branches. Little to no impact from hail is expected.

Locations impacted include...
Worcester, Leominster, Fitchburg, Holden, Clinton, Pepperell, Groton,
Lunenburg, Townsend, Lancaster, Rutland, Sterling, West Boylston,
Ayer, Westminster, Shirley, Harvard, Ashburnham, Boylston and
Princeton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.

&&

LAT...LON 4270 7152 4270 7151 4231 7176 4240 7193
      4271 7185
TIME...MOT...LOC 2132Z 198DEG 21KT 4242 7177

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Frank

Special Weather Statement
National Weather Service Boston/Norton MA
548 PM EDT Wed Jun 14 2023

MAZ004-010>012-142230-
Southern Worcester MA-Eastern Hampden MA-Northern Worcester MA-
Eastern Hampshire MA-
548 PM EDT Wed Jun 14 2023

...A strong thunderstorm will impact portions of southwestern
Worcester, eastern Hampshire and east central Hampden Counties
through 630 PM EDT...

At 547 PM EDT, Doppler radar was tracking a strong thunderstorm over
Brookfield, or 15 miles southwest of Worcester, moving north at 25
mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Strong winds could cause minor damage such as downed
         branches. Little to no impact from hail is expected.

Locations impacted include...
Southbridge, Charlton, Palmer, Spencer, Ware, Sturbridge, Monson,
Rutland, Barre, Warren, Paxton, North Brookfield, West Brookfield,
Brimfield, Brookfield, Hardwick, Holland, East Brookfield, Oakham and
Wales.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.

&&

LAT...LON 4204 7205 4210 7233 4239 7223 4235 7195
TIME...MOT...LOC 2147Z 198DEG 21KT 4217 7209

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Frank

Special Weather Statement
National Weather Service Boston/Norton MA
615 PM EDT Wed Jun 14 2023

MAZ004>006-026-142315-
Northwest Middlesex County MA-Central Middlesex County MA-
Western Essex MA-Northern Worcester MA-
615 PM EDT Wed Jun 14 2023

...A strong thunderstorm will impact portions of west central Essex,
east central Worcester and north central Middlesex Counties through
715 PM EDT...

At 615 PM EDT, Doppler radar was tracking a strong thunderstorm over
Bolton, or near Marlborough, moving northeast at 25 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Strong winds could cause minor damage such as downed
         branches. Little to no impact from hail is expected.

Locations impacted include...
Lowell, Lawrence, Methuen, Billerica, Marlborough, Chelmsford,
Andover, Dracut, Tewksbury, Westford, Acton, Hudson, Concord,
Sudbury, Clinton, Pepperell, Tyngsborough, Groton, Maynard and
Littleton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.

&&

LAT...LON 4273 7112 4233 7153 4243 7168 4271 7163
      4270 7129 4273 7127 4275 7123 4274 7119
      4275 7118
TIME...MOT...LOC 2215Z 227DEG 20KT 4243 7158

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Frank

Special Weather Statement
National Weather Service Boston/Norton MA
650 PM EDT Wed Jun 14 2023

MAZ020-RIZ007-142330-
Southern Bristol MA-Newport RI-
650 PM EDT Wed Jun 14 2023

...A strong thunderstorm will impact portions of southeastern Bristol
and southeastern Newport Counties through 730 PM EDT...

At 649 PM EDT, Doppler radar was tracking a strong thunderstorm over
Little Compton, or 10 miles east of Newport, moving northeast at 25
mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Strong winds could cause minor damage such as downed
         branches. Minor damage to outdoor objects is possible.

Locations impacted include...
New Bedford, Dartmouth, Portsmouth, Fairhaven, Tiverton, Westport and
Little Compton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.

&&

LAT...LON 4152 7121 4153 7126 4153 7121 4156 7121
      4170 7095 4160 7082 4158 7082 4165 7092
      4159 7090 4161 7092 4158 7093 4160 7096
      4153 7096 4149 7104 4151 7107 4150 7113
      4146 7117
TIME...MOT...LOC 2249Z 237DEG 24KT 4150 7113

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

Frank

Special Weather Statement
National Weather Service Boston/Norton MA
651 PM EDT Wed Jun 14 2023

MAZ013-016>019-142330-
Eastern Plymouth MA-Western Norfolk MA-Northern Bristol MA-
Eastern Norfolk MA-Western Plymouth MA-
651 PM EDT Wed Jun 14 2023

...A strong thunderstorm will impact portions of east central
Norfolk, northwestern Plymouth and north central Bristol Counties
through 730 PM EDT...

At 651 PM EDT, Doppler radar was tracking a strong thunderstorm over
Brockton, moving northeast at 30 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Strong winds could cause minor damage such as downed
         branches. Little to no impact from hail is expected.

Locations impacted include...
Brockton, Weymouth, Braintree, Randolph, Stoughton, Bridgewater,
Marshfield, Easton, Hingham, Scituate, Pembroke, Sharon, Rockland,
Abington, Duxbury, Whitman, Hanover, East Bridgewater, Holbrook and
Norwell.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.

&&

LAT...LON 4197 7102 4211 7115 4226 7089 4225 7088
      4227 7086 4224 7077 4225 7077 4220 7072
      4221 7071 4217 7071 4217 7073 4215 7071
      4216 7071 4216 7070 4210 7066
TIME...MOT...LOC 2251Z 237DEG 24KT 4208 7100

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Frank