Alert archive / Connecticut / Severe Thunderstorm Warnings in 2023
Severe Thunderstorm Warning 32, NWS Boston/Norton, MA
NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 27, 2023, 4:03 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut; Hampden County, Hampshire County, Worcester County, Massachusetts. It was in force for 57 min. 13 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 27, 2023, 4:03 PM EDT (20:03 UTC)
- Expired
- Jul 27, 2023, 5:00 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 Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Hampden County, MA, Hampshire County, MA, Worcester County, MA
The radar
The Albany radar (KENX), 122 km from the middle of the area, began a volume at 20:05 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 27, 4:12 PM EDT | TSTM WND DMG | 1 Wsw Chicopee, MA | In Chicopee, a tree was down on Grattan Street. |
| Jul 27, 4:12 PM EDT | TSTM WND DMG | 3 W Westfield, MA | In Westfield, two trees were down on Bates Road by Belden Drive. |
| Jul 27, 4:12 PM EDT | TSTM WND DMG | Chicopee, MA | In Chicopee, a tree was down on Grattan Street. Another tree was down at the intersection of Granby Road and Springfield Street. |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | 2 Ese West Springfield, MA | In West Springfield, multiple limbs were down on Park Avenue. |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | 2 Nw Springfield, MA | In Springfield, a tree and wires were down in the 100 block of Victoria Street. Also, a tree was partially down on the roadway on Plainfield Street. |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | 2 Nw Springfield, MA | In Springfield, a tree and wires were down in the 100 block of Victoria Street. Also, a tree was partially down on the roadway on Plainfield Street. Trees were down on Allen Street. A tree was down on Fairfield Street. Multiple trees and wires were down on New |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | 2 Nw Springfield, MA | In Springfield, a tree and wires were down in the 100 block of Victoria Street. Also, a tree was partially down on the roadway on Plainfield Street. Trees were down on Allen Street. A tree was down on Fairfield Street. Wires were down on Newhouse Street. |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | Springfield, MA | Corrects previous tstm wnd dmg report from 2 NW Springfield. In Springfield, a tree and wires were down in the 100 block of Victoria Street. Also, a tree was partially down on the roadway on Plainfield Street. Trees were down on Allen Street. A tree was down o |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | Springfield, MA | Corrects previous tstm wnd dmg report from 2 NW Springfield. In Springfield, a tree and wires were down in the 100 block of Victoria Street. Also, a tree was partially down on the roadway on Plainfield Street. Trees were down on Allen Street. A tree was down o |
| Jul 27, 4:15 PM EDT | TSTM WND DMG | Springfield, MA | In Springfield, a tree and wires were down in the 100 block of Victoria Street. Also, a tree was partially down on the roadway on Plainfield Street. Trees were down on Allen Street. A tree was down on Fairfield Street. Multiple trees and wires were down on New |
| Jul 27, 4:32 PM EDT | TSTM WND DMG | 3 Wnw Palmer, MA | In Palmer, a tree was down on power lines on Maple Street at Maple Terrace. |
| Jul 27, 4:44 PM EDT | TSTM WND DMG | 4 Ese Belchertown, MA | In Belchertown, a tree was down on wires on East Street. |
| Jul 27, 4:55 PM EDT | TSTM WND DMG | 2 Nw Charlton, MA | In Charlton, power lines were down on Brookfield Road near Osgood Road. |
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 13 storm reports to this severe thunderstorm warning; the first came 9 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 27, 12:48 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 8.1 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.
- Mixed-layer CAPE
- 102 J/kg
- Mixed-layer CIN
- -145 J/kg
- Mixed-layer LCL
- 869 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 182 m²/s²
- 0-3 km storm-relative helicity
- 211 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
843
WUUS51 KBOX 272003
SVRBOX
CTC003-013-015-MAC013-015-027-272100-
/O.NEW.KBOX.SV.W.0032.230727T2003Z-230727T2100Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
403 PM EDT Thu Jul 27 2023
The National Weather Service in Boston/Norton has issued a
* Severe Thunderstorm Warning for...
Northern Windham County in northern Connecticut...
Northern Tolland County in northern Connecticut...
Northern Hartford County in northern Connecticut...
Southwestern Worcester County in central Massachusetts...
Southern Hampshire County in western Massachusetts...
Hampden County in western Massachusetts...
* Until 500 PM EDT.
* At 400 PM EDT, a severe thunderstorm was located over West
Springfield, moving east at 35 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...The Westfield ASOS just reported a wind gusts of 66 mph.
These are dangerous storms that will produced wind damage.
IMPACT...Expect damage to trees and power lines.
* Locations impacted include...
Worcester, Springfield, Chicopee, Enfield, Westfield, Holyoke,
Amherst, Northampton, Agawam, West Springfield, Ludlow, South
Hadley, Holden, Webster, Southbridge, Auburn, Easthampton,
Longmeadow, Suffield and East Longmeadow.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4215 7307 4214 7305 4215 7303 4230 7300
4234 7235 4232 7235 4230 7236 4234 7231
4237 7179 4194 7188 4192 7290 4197 7289
4197 7303 4204 7301 4204 7306
TIME...MOT...LOC 2002Z 266DEG 32KT 4216 7263
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
Frank2 follow-up statements
457
WWUS51 KBOX 272019
SVSBOX
Severe Weather Statement
National Weather Service Boston/Norton MA
419 PM EDT Thu Jul 27 2023
CTC003-013-015-MAC013-015-027-272100-
/O.CON.KBOX.SV.W.0032.000000T0000Z-230727T2100Z/
Windham CT-Tolland CT-Hartford CT-Worcester MA-Hampshire MA-
Hampden MA-
419 PM EDT Thu Jul 27 2023
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR NORTHERN WINDHAM...NORTHERN TOLLAND...NORTHERN HARTFORD...
SOUTHWESTERN WORCESTER...SOUTHERN HAMPSHIRE AND HAMPDEN COUNTIES...
At 417 PM EDT, a severe thunderstorm was located over Ludlow, or near
Springfield, moving east at 35 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Trained weather spotters that these storms have resulted in
wind damage. This is particularly true in the Westfield
area where the ASOS recorded a 66 mph wind gusts as the
storms moved across the region.
IMPACT...Expect damage to trees and power lines.
Locations impacted include...
Worcester, Springfield, Chicopee, Enfield, Westfield, Holyoke,
Amherst, Northampton, Agawam, West Springfield, Ludlow, South Hadley,
Holden, Webster, Southbridge, Auburn, Easthampton, Longmeadow,
Suffield and East Longmeadow.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
This is a DANGEROUS SITUATION. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4215 7307 4214 7305 4215 7303 4230 7300
4234 7235 4232 7235 4230 7236 4234 7231
4237 7179 4194 7188 4192 7290 4197 7289
4197 7303 4204 7301 4204 7306
TIME...MOT...LOC 2017Z 266DEG 32KT 4217 7244
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
Frank254
WWUS51 KBOX 272029
SVSBOX
Severe Weather Statement
National Weather Service Boston/Norton MA
429 PM EDT Thu Jul 27 2023
CTC003-013-015-MAC013-015-027-272100-
/O.CON.KBOX.SV.W.0032.000000T0000Z-230727T2100Z/
Windham CT-Tolland CT-Hartford CT-Worcester MA-Hampshire MA-
Hampden MA-
429 PM EDT Thu Jul 27 2023
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR NORTHERN WINDHAM...NORTHERN TOLLAND...NORTHERN HARTFORD...
SOUTHWESTERN WORCESTER...SOUTHEASTERN HAMPSHIRE AND HAMPDEN
COUNTIES...
At 428 PM EDT, a severe thunderstorm was located over Palmer, or 12
miles east of Springfield, moving east at 35 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Trained weather spotters have reported a history of wind
damage with these storms.
IMPACT...Expect damage to trees and power lines.
Locations impacted include...
Worcester, Springfield, Chicopee, Enfield, Westfield, Holyoke,
Amherst, Agawam, West Springfield, Ludlow, South Hadley, Holden,
Webster, Southbridge, Auburn, Easthampton, Longmeadow, Suffield, East
Longmeadow and Ellington.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4215 7307 4214 7305 4215 7303 4220 7302
4234 7235 4232 7235 4230 7236 4234 7231
4237 7179 4194 7188 4192 7290 4197 7289
4197 7303 4204 7301 4204 7306
TIME...MOT...LOC 2028Z 266DEG 32KT 4218 7231
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
FrankWhat 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 27, 2:12 PM EDT, 1 hour 51 minutes earlier.
Area forecast discussion, Jul 27, 2:12 PM EDT, 1 hour 51 minutes before
Area Forecast Discussion
National Weather Service Boston/Norton MA
212 PM EDT Thu Jul 27 2023
.SYNOPSIS...
Heat indices reach oppressive levels today, along with the risk
for severe thunderstorms and localized flash flooding in the
early afternoon into early evening. Oppressive heat and
humidity continues Friday and Saturday. Dry weather expected on
Friday. Another round of severe storms and flash flooding are
possible on Saturday as a cold front slides through. Behind the
front cooler and more comfortable conditions are expected Sunday
into the middle of next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
2 PM Update:
* Severe Thunderstorm Watch In Effect until 8 PM for all of
Southern New England; excluding Cape Cod and the Islands.
Storms currently popping up across eastern NY to northeast PA of
which, storms are already becoming severe with warnings. Latest
SPC meso analysis does show the better forcing, low level
helicity and bulk effective shear pushing into central New
England; ie New Hampshire and portions of western Maine. Never
the less, there is still enough shear with 35 to 40 knots and
low level helicity of 100 m2/s2 over the region. Additionally,
there is plenty of CAPE, the mixed layer MLCAPE is between 1500
and 2000 units, this should help to over compensate for the less
than ideal mid lapse rates. Low level lapse rate are adequate
around 6.5C/km to 7C/km, mid levels are closer to 5.5C/km and
6C/km.
We are closely watching storm coming out of eastern NY as these
storms enter a more favorable environment. To reiterate our
main concerns are storms that would be capable of damaging
straight-line gusts, flash flooding, hail, and still can not
rule out a brief tornado or two.
Over all the forecast remains well on track, no changes have
been made at this time. See the previous forecast discussion
below for more information.
10:30 AM Update...
A warm front lifts across the region and has sparked a showers
across northwest Massachusetts, but for now KBOX is quiet. We
are expecting this afternoon to be fairly busy, likely one of
the more active days this summer, perhaps the past couple of
years.
As mentioned, the cloud cover could become a limiting factor for
daytime heating and instability. There remains clouds across
western MA & CT - likely associated with the deep southwest flow
advecting higher PWATs/humidity into the region. A quick look at
dewpoints are lower 70s, do expect these dewpoints to climb a
few more degrees this morning. Looking further west, we are
noticing breaks in the clouds, southwest of ALY and points
southwest into eastern PA.
A quick meso analysis shows the surface low near the Saint
Lawrence River Valley of northern New York, before traversing
east into northern Vermont. It is subtle, but a prefrontal
trough appears around 2 PM along with an uncapped 1,000 to 1,500
units of MLCAPE, 40kts of effective bulk shear, and 100 to 200
units of storm relative helicity.
Over all the forecast remains well on track, no changes have
been made at this time. See the previous forecast discussion
below for more information.
405 AM Update:
Key Points:
* Severe Thunderstorms Anticipated Early This Afternoon into
Early Tonight. Damaging straight line winds, frequent
lightning and torrential rain capable of flash flooding are
possible. A risk for brief tornadoes in western and central
portions of MA and CT as well.
* Oppressive Heat and Humidity with Heat Indices Nearing 100
Degrees.
* High Surf and Rip Currents along the southern facing coasts
* Hazardous Conditions for Recreational Boaters from Gale-force
Gusts (and potential for thunderstorms)
A very active Thursday is expected for much of Southern New
England, spanning several weather-related concerns. Midsummer
heat and elevated humidity (even in spite of some high clouds)
will drive high heat indices and oppressive heat. Meanwhile, a
potent mid-level disturbance now over the western Great Lakes
will act on this high heat and humidity, leading to an
anticipated development of severe thunderstorms, potentially in
multiple rounds/series. The thunderstorm setting features a
combination of strong low level wind shear/helicity driven by
strong low-level southwesterly flow, along with moderately high
instability. Without hyperbole, and while there are
uncertainties, this type of thunderstorm environment is
uncommonly if rarely seen in Southern New England. These
thunderstorms may also produce heavy to excessive rains and
given the saturated conditions in place, flooding will again be
possible in some locations. Finally, due to the strong winds and
building seas, there is a risk for high surf and rip currents
on south-facing beaches. The risk for rip currents also needs to
be messaged, as the heat/humidity combo I'm sure may lead many
to the beach.
In terms of headlines: we opted to expand the existing Flood
Watch southward into CT-RI and adjacent SE MA to account for the
potential for multiple rounds of thunderstorms this afternoon
into early tonight into these locations, matching the same
flooding concerns for most of MA. The Heat Advisory was also
expanded southward to include more of the South Coast.
A little more detail on each hazard below...
Severe Thunderstorms:
As mentioned, model guidance is showing some greater
consistency in an environment of higher lower level wind shear
along with moderately high instability values. An approaching
disturbance seen on water vapor imagery coming off of Lake Erie
will bring increased 925 to 850 mb low level SW flow up to 45 kt
to Southern New England this morning. Kinematically it's pretty
uncommon to see stronger flow in the lowest portions of the
atmosphere than in the mid and upper portions of atmosphere
(aside from a tropical cyclone). Because of that, deep layer
shear is only borderline supportive of organized convection, but
it's the portion of flow/shear in the lowest 3 km of atmosphere
that's more concerning. Models simulate curved lower-level
hodographs across interior central and western MA and CT due to
stronger low level flow (0-1 km storm relative helicity values
up to 250 m2/s2 in some locations in western MA and CT). These
values weaken somewhat by early to mid afternoon, but certainly
with the ground being as wet as it is from the spate of July
2023 rains, trees are more vulnerable to being downed than they
ordinarily might be from stronger gusts.
Mid to high clouds may dampen how warm and how much we can
destabilize. But with enough clearing anticipated We expect
development of initial cells around noon to 2 PM across the
Berkshires into central MA and Hartford/Tolland Counties in CT,
best depicted by the 00z HRRR, WRF-NSSL and WRF-ARW CAM
solutions. While the higher storm relative helicity values will
be weakening, its these initial storms moving off to the E or
ESE that will need to be watched very closely for the risk for
brief tornadoes and straight line wind damage. It remains
unclear how long storms may stay as cells, but another round of
storms taking form of lines or line segments posing a
predominant strong to damaging wind risk will then develop and
move eastward from interior MA/CT into the North Shore, Boston-
Providence I-95 corridor and SE MA late this afternoon, possibly
coinciding with the PM commute.
To emphasize: this is a severe weather setting which is uncommonly
experienced in Southern New England, and the potential for brief
tornadoes and straight-line wind damage is a credible risk in
environments like this one. If you do have plans outdoors, it's
vital to keep an eye to the sky and to have multiple ways to receive
later statements, and that's especially true in western interior
sections of MA and CT where the greatest potential for severe
weather exists.
Flooding:
See the added Hydrology section below.
Oppressive Heat and Humidity:
We did opt to expand the Heat Advisory southward to include the
South Coast. Because of at least some cloudiness around, and that
southerly flow will be quite strong, it's admittedly more borderline
and not your typical hazy/hot/humid day. Highs should again reach
into the upper 80s to mid 90s, with heat indices in the middle to
upper 90s for today. It is possible that some areas may fall just
short of meeting the heat index criteria because of anticipated
cloud cover and the potential for thunderstorms. But it still likely
will be pretty oppressive and we still encourage frequent breaks
indoors.
High Surf and Rip Currents:
Increasing southerly fetch will draw higher waves into southern
facing beaches, and southerly winds into the surf zone will generate
high surf and breaking waves on these beaches. As many will likely
be flocking to the beaches to beat the heat today, the risk for rip
currents is one that also needs to be messaged.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
405 AM Update:
Convection likely to weaken and/or shift offshore early tonight,
with improving conditions toward drier weather as flow turns
westerly. May still have to watch for patchy radiation fog given
recent wet ground. Very warm and muggy lows in the lower to mid
70s.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Highlights
* Oppressive heat/humidity continues Fri and Sat.
* Strong to severe storms possible Sat. Heavy downpours could result
in localized flash flooding.
* Cooler and less humid Sun and into next week.
Friday...
A mid level ridge will build from the the central Great Lakes early
in the day into the eastern Great Lakes/western New England by late
on Fri. A weak high will nudge into southern New England.
Dangerous heat expected to continue across southern New England.
Still looks like the peak of the heat temp wise will be on Fri. Will
see W to WNW flow at 925 hPa with temps of 23-26 degrees C.
Anticipating strong mixing per NAM/GFS Bufkit soundings, so bumped
temps up toward the 90th percentile of guidance. Should see
widespread highs in the low/mid 90s. Though it may stay in the 80s
along the immediate coastline as the seabreeze develops. Did nudge
down our dew points a bit given the W/WNW flow and deep mixing. Did
not go quite as low as ARW/FV3 guidance, but it is not out of the
question especially if you mix down the dew points at the top of the
mixed layer. Due to this have dew points in the mid 60s to lower
70s. The result are heat indices between 90-100, so think the
current Heat Advisory still looking good.
Given the stronger wind fields that were in place on Thu/Thu night
think that south facing beaches still could see a moderate risk for
rips despite wave heights diminishing. Beachgoers will want to
remain vigilant.
Friday Night through Saturday...
Mid level ridge axis over the eastern Great Lakes/New England Fri
eve builds offshore by early Sat. The next shortwave/trough lifts in
from the Great Lakes region early in the day and eventually through
by the evening. This will slide a cold front through the region and
perhaps another MCs.
Main change to the forecast was to extend the Heat Advisory across
portions of the south coast, Merrimack and CT Valley through late
Sat. Not expecting much relief from the heat Fri night into Sat as
flow turns more to the WSW/SW at 925 hPa. This will surge upper 60
to mid 70 degree dew points into our region. Expecting overnight
lows to hover right around those dew points, so will be quite warm as
we head into Sat. The question on Sat will be how quickly the front
moves in and if a MCs impacts us. At this point have more confidence
in the heat/humidity during the first half of the day. Ahead of the
incoming front the WSW/SW flow will bring 20-25 degree C overhead at
925 hPa. The result will be highs in the mid 80s to low 90s. Should
see more widespread low 90 degree readings where the Heat Advisory
has been expanded, much of the CT River Valley/south coast and into
the Merrimack Valley. Dew points will be in the low/mid 70s, so heat
indices range from the mid 80s to upper 90s.
On top of the heat concern will have another day where there is a
risk of scattered strong to severe thunderstorms. Somewhat uncertain
to the exact location/track of an MCs pushing in from the west.
Quite difficult to pinpoint these things 3 days out. Our environment
looks quite favorable with deep layer shear in the 0-6 km layer of
30-50 kts as the cold front is sliding in. Instability at this point
looks like roughly a few hundred to perhaps 1000 J/kg of MLCAPE. Low
level lapse rates are 6-8 degrees C and mid level lapse rates are
the typical meh around 5-6. Another anomalous 1.5-2+ inch PWAT plume
advects in with warm cloud layer depths of 3-4.5 km. Given the
environment will have the risk for scattered strong/severe storms
and localized flash flooding. The severe risk highlighted quite well
by the latest CSU ML probs for Day 3 with a 15-30 percent chance of
a severe wind risk for our area and low probs for a hail threat.
Did dial back the default NBM precip chances as am just not sure
where the MCs coming in from the west will track. The GFS/ECWMF
guidance puts us more under the risk whereas the NAM/CMC
highlighting a bit further south. If the NAM is correct then we
could actually have parts of the region where we get no precip.
Given the uncertainty capped things at chances of precip. Hopefully
will have better agreement later today/Fri.
Sunday through Wednesday...
Should see relief from the heat as a more seasonable airmass moves
in behind the cold front. Flow looks like it will be cyclonic
through at least early in the week before a ridge builds into the
Great Lakes region by roughly mid week. Given the cyclonic flow
there does appear there will be a few shortwaves/troughs lifting
through. Tough to time these things this far out especially given
they likely are going to be convectively driven.
Does appear that we are drier and less humid, however given the
upper forcing am not sure we will be completely dry through this
period. Did bump up precip chances on Sun to show an isolated risk
for showers as a shortwave lifts in. Could see some isolated
showers/storms on Mon/Tue across the interior as more waves swing
in. Definitely not looking like there are any washouts at this point
in time. Temps range from the mid 70s to the mid 80s for highs each
day.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Today...High confidence in trends, moderate on exact timing of
t-storms moving through.
Gusty southwest winds 25 to 35 knots out ahead of any storms due
to a strong low level jet. VFR, areas of MVFR around southeast
Massachusetts and Cape Cod. TSRA developing across eastern New
York at 18z. Expect these storms to move east this afternoon,
impacting western terminals between 19z/22z, then eastern
terminals between 20z/23z. Storms will be capable of strong wind
gusts, frequent lightning, and hail. Additionally, storms may
temporarily reduce flight ceilings from VFR/MVFR to IFR/LIFR. We
remain uncertain how for southeast the storms will go before
weakening, did leave out TSRA out of PVD, opt for VCTS due to
lower confidence.
Tonight...High confidence.
Weakening showers/tstorms along the immediate southern coast
gives way to VFR conditions for most. Will have to watch for
patchy/localized IFR-LIFR radiation fog upon clearing, though
west winds 5 to 10 knots may preclude development. IFR to LIFR
stratus/fog pushing into the Cape/Island terminals.
Tomorrow...High confidence.
VFR. West winds become southwest around 5-10 knots, with sea
breezes along the eastern MA coast.
KBOS TAF...High confidence in trends and moderate confidence in
timing. VFR and gusty southwest winds 25 to 35 knots. TSRA
possible between 21z/24z. Storms may temporarily reduce
ceilings to IFR/LIFR conditions along with stronger wind gusts
and frequent lightning. Winds easing after 04z/06z with VFR
conditions returning.
KBDL TAF...High confidence in trends and moderate confidence in
timing. Southwest wind gusts up to 25 knots are possible. TSRA
then possible after 1930Z, with a better chance for storms to
reach severe levels. VFR conditions due return overnight, though
some models show low stratus potentially developing between
09z/12z, ran with a TEMPO for now due to lower confidence.
Outlook /Friday through Monday/...
Friday Night: VFR.
Saturday: VFR. Breezy. Chance SHRA, slight chance TSRA.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA, slight chance TSRA.
Sunday: VFR. Slight chance SHRA.
Sunday Night through Monday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
230 AM Update:
Key Points:
* Gale Force Wind Gusts on Nearshore Waters & Rough Seas Today
* Hazardous Conditions for recreational boaters
* Strong to Severe T-storms Late Afternoon/Early Tonight
Today through Friday...High Confidence.
Have converted existing Gale Watch to a Gale Warning for the
nearshore southern waters. While SW gusts are on the lower end
of Gale criteria, given peak boating season and the rather
anomalous magnitude of the southwest lower-level jet by late
July standards, we felt it appropriate to message these gusts
with a gale warning along the nearshore marine zones where
mixing may be slightly deeper adjacent to the very warm land.
SCAs continue on the remaining waters where mixing may be
shallower and more limited to 25-30 kt gusts.
Seas become quite rough building to between 3 and 7 feet across
most open waters.
In addition...a few strong to severe thunderstorms may impact
the nearshore waters later this afternoon and early tonight.
This is especially true for the waters near and north the
Plymouth/Marshfield areas.
The southwest LLJ will depart the region later Thu evening and
night allowing winds to diminish. Lingering swell will also
diminish...but at a slower rate so small craft headlines for
rough seas will continue into Friday across some of our southern
waters.
Outlook /Friday through Monday/...
Friday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.
Saturday through Saturday Night: Winds less than 25 kt. Areas
of seas approaching 5 ft. Chance of rain showers, slight chance
of thunderstorms.
Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.
Sunday Night: Winds less than 25 kt. Slight chance of rain
showers.
Monday: Winds less than 25 kt.
&&
.HYDROLOGY...
405 AM Update:
Flood Watch in effect today and into tonight for most of MA
(excluding eastern Plymouth County and the Cape and Islands),
all of northern CT and much of RI (excluding Washington County).
Antecedent conditions remain little changed and that being that
soil moisture and streamflow conditions are high. We are
expecting another round of thunderstorms capable of not just
instances of severe weather, but also locally heavy to
torrential rainfall. While its not entirely clear how storms may
develop and evolve, there is potential for training of storms
moving over the same areas repeatedly. This may lead to
development of urban and poor drainage flooding, sharp rises on
streams, creeks and tributaries over bankfull, along with
possible instances of rapid onset flooding. Steering flow with
today's thunderstorms is a lot stronger than typical, but given
the antecedent conditions, new areas of flooding may develop
this afternoon and early tonight until storms end.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch until midnight EDT tonight for CTZ002>004.
Heat Advisory until 8 PM EDT Saturday for CTZ002>004.
MA...Flood Watch until midnight EDT tonight for MAZ002>018-020-021-
026.
Heat Advisory until 8 PM EDT Saturday for MAZ005-010>021.
Heat Advisory until 8 PM EDT Friday for MAZ003-004-006-007-026.
High Surf Advisory until 8 PM EDT this evening for MAZ020>024.
RI...Flood Watch until midnight EDT tonight for RIZ001>005-007.
Heat Advisory until 8 PM EDT Saturday for RIZ001>007.
High Surf Advisory until 8 PM EDT this evening for RIZ006>008.
MARINE...Small Craft Advisory until 2 AM EDT Friday for ANZ230-250-251.
Gale Warning until midnight EDT tonight for ANZ231>237.
Small Craft Advisory until 8 AM EDT Friday for ANZ254>256.
&&
SYNOPSIS...Loconto/BL
NEAR TERM...Loconto/Dooley
SHORT TERM...Loconto
LONG TERM...BL
AVIATION...BL/Dooley
MARINE...Loconto/BL
HYDROLOGY...Hazardous weather outlook, Jul 27, 12:05 PM EDT, 3 hours 58 minutes before
Hazardous Weather Outlook National Weather Service Boston/Norton MA 1205 PM EDT Thu Jul 27 2023 MAZ003-004-006-007-026-281615- Eastern Franklin MA-Northern Worcester MA-Western Essex MA- Eastern Essex MA-Northern Middlesex MA- 1205 PM EDT Thu Jul 27 2023 ...FLOOD WATCH IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT FRIDAY... This Hazardous Weather Outlook is for central Massachusetts, eastern Massachusetts, northeastern Massachusetts and western Massachusetts. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flood Watch. Heat Advisory. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. An isolated tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. CTZ002>004-MAZ005-010>018-RIZ001>005-281615- Hartford CT-Tolland CT-Windham CT-Central Middlesex 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- Northwest Providence RI-Southeast Providence RI-Western Kent RI- Eastern Kent RI-Bristol RI- 1205 PM EDT Thu Jul 27 2023 ...FLOOD WATCH IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT SATURDAY... This Hazardous Weather Outlook is for northern Connecticut, central Massachusetts, eastern Massachusetts, southeastern Massachusetts, western Massachusetts and northern Rhode Island. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flood Watch. Heat Advisory. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. An isolated tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. MAZ002-008-009-281615- Western Franklin MA-Western Hampshire MA-Western Hampden MA- 1205 PM EDT Thu Jul 27 2023 ...FLOOD WATCH IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... This Hazardous Weather Outlook is for western Massachusetts. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flood Watch. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. An isolated tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. RIZ006-281615- Washington RI- 1205 PM EDT Thu Jul 27 2023 ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT SATURDAY... ...HIGH SURF ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING... This Hazardous Weather Outlook is for southern Rhode Island. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. High Surf Advisory. Heat Advisory. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. An isolated tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. MAZ022>024-RIZ008-281615- Barnstable MA-Dukes MA-Nantucket MA-Block Island RI- 1205 PM EDT Thu Jul 27 2023 ...HIGH SURF ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING... This Hazardous Weather Outlook is for southeastern Massachusetts and southern Rhode Island. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. High Surf Advisory. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. MAZ020-021-RIZ007-281615- Southern Bristol MA-Southern Plymouth MA-Newport RI- 1205 PM EDT Thu Jul 27 2023 ...FLOOD WATCH IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT SATURDAY... ...HIGH SURF ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING... This Hazardous Weather Outlook is for southeastern Massachusetts and southern Rhode Island. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. High Surf Advisory. Flood Watch. Heat Advisory. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. An isolated tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. MAZ019-281615- Eastern Plymouth MA- 1205 PM EDT Thu Jul 27 2023 ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT SATURDAY... This Hazardous Weather Outlook is for southeastern Massachusetts. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. A few severe thunderstorms, with damaging winds and large hail, are possible this afternoon and evening. An isolated tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Heat Advisory. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. ANZ230-250-251-254>256-281615- Boston Harbor- 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- 1205 PM EDT Thu Jul 27 2023 This Hazardous Weather Outlook is for Massachusetts coastal waters and Rhode Island coastal waters. .DAY ONE...This afternoon and 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>237-281615- Cape Cod Bay-Nantucket Sound-Vineyard Sound-Buzzards Bay- Rhode Island Sound-Narragansett Bay-Block Island Sound- 1205 PM EDT Thu Jul 27 2023 ...GALE WARNING IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... This Hazardous Weather Outlook is for Massachusetts coastal waters and Rhode Island coastal waters. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Gale Warning. .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/NWSBoston You can follow us on Twitter at @NWSBoston
In the hours before
Special weather statement, Jul 27, 11:46 AM EDT, 4 hours 17 minutes before
Special Weather Statement National Weather Service Boston/Norton MA 1146 AM EDT Thu Jul 27 2023 CTZ002>004-MAZ002>024-026-RIZ001>008-272100- 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- Including the cities of Hartford, Windsor Locks, Union, Vernon, Putnam, Willimantic, Charlemont, Greenfield, Orange, Barre, Fitchburg, Framingham, Lowell, Lawrence, Gloucester, Chesterfield, Blandford, Amherst, Northampton, Springfield, Milford, Worcester, Foxborough, Norwood, Cambridge, Boston, Quincy, Taunton, Brockton, Plymouth, Fall River, New Bedford, Mattapoisett, Chatham, Falmouth, Provincetown, Vineyard Haven, Nantucket, Ayer, Foster, Smithfield, Providence, Coventry, West Greenwich, East Greenwich, Warwick, West Warwick, Bristol, Narragansett, Westerly, Newport, and New Shoreham 1146 AM EDT Thu Jul 27 2023 ...SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING ACROSS SOUTHERN NEW ENGLAND... Severe thunderstorms, with damaging wind and large hail, are possible across southern New England this afternoon and evening. The main threat will be between 2 PM and 10 PM. In addition, an isolated tornado cannot be ruled out. Heavy downpours may cause localized flooding. Skywarn weather spotters should be prepared to relay reports of severe weather to the National Weather Service. Stay tuned to the latest weather information and listen for severe weather watches and warnings. Remember, when thunder roars, go indoors. There is no safe place outdoors when lightning is striking. Field
The office that day
Everything else NWS Boston/Norton, MA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 27, 3:10 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 65 min |
| Jul 27, 4:35 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 55 min |
| Jul 27, 5:22 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region, Northeastern Connecticut Planning Region | 53 min |
| Jul 27, 5:50 PM EDT | Severe Thunderstorm Warning | BOX | Northeastern Connecticut Planning Region | 55 min |
| Jul 27, 7:24 PM EDT | Severe Thunderstorm Warning | BOX | Northeastern Connecticut Planning Region | 51 min |
| Jul 27, 1:58 AM EDT | Gale Warning | BOX | 22 hr | |
| Jul 27, 3:09 PM EDT | Rip Current Statement | BOX | Barnstable, Bristol, Dukes, Nantucket, Plymouth | 26 hr |
| Jul 27, 5:01 PM EDT | Special Weather Statement | BOX | Norfolk, Worcester | 44 min |
| Jul 27, 5:24 PM EDT | Special Weather Statement | BOX | Norfolk | 66 min |
| Jul 27, 5:27 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Norfolk, Suffolk, Worcester | 48 min |
| Jul 27, 5:53 PM EDT | Special Marine Warning | BOX | 67 min | |
| Jul 27, 5:57 PM EDT | Special Marine Warning | BOX | 63 min | |
| Jul 27, 6:01 PM EDT | Severe Thunderstorm Warning | BOX | Essex, Middlesex, Norfolk, Plymouth, Suffolk, Worcester | 59 min |
| Jul 27, 6:37 PM EDT | Severe Thunderstorm Warning | BOX | Bristol, Norfolk, Plymouth | 53 min |
| Jul 27, 6:51 PM EDT | Special Marine Warning | BOX | 39 min | |
| Jul 27, 7:43 PM EDT | Special Marine Warning | BOX | 47 min |
Nearby
Severe Thunderstorm Warnings in Connecticut, 2023Severe Thunderstorm Warnings in Massachusetts, 2023Every severe thunderstorm warning in 2023
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.