An anomalously amplified mid level trough moving east from the Great Lakes closed off and brought widespread showers and scattered thunderstorms which lead to flooding in western and central Massachusetts. Many roads were closed and cars were stuck in flood waters.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BOX wrote it up.
An anomalously amplified mid level trough moving east from the Great Lakes closed off and brought widespread showers and scattered thunderstorms which lead to flooding in western and central Massachusetts. Many roads were closed and cars were stuck in flood waters.
The local office's own words before the first event, 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 the first event at Jul 10, 5:27 AM EST, 2 hours 7 minutes earlier.
Area Forecast Discussion National Weather Service Boston/Norton MA 627 AM EDT Mon Jul 10 2023 .SYNOPSIS... Widespread showers and scattered thunderstorms with heavy rainfall will move across the region today. The highest risk for significant flooding will be across far western New England. Showers will be lifting to the north tonight. Drier weather Tuesday, then hot and humid conditions return Wednesday. The dry weather pattern is brief, with rain chances increasing through the end of the workweek. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 630 AM Update Forecast remains on track. KBOX radar beginning to reveal moderate to heavy rainfall across western MA and CT this morning. Expect moderate to heavy rainfall to continue into the afternoon. Radar reflectivity over Rhode Island is more of the light to moderate category at this hour, but more intense rainfall rates are forecast to develop over this area over the next couple of hours. No flash flood warnings have been issued at this time, but special weather statements are in effect for most of Hartford county and the areas west of I-91 to the east slopes of The Berkshires. We'll continue to monitor trends and may issue flash flood warnings where appropriate. No changes have been made to the forecast for today, see further details in the previous discussion. Previous Discussion Highlights... * Highest risk for flash flooding through the morning will be from the Berkshires to western CT * Secondary maximum of heavy rainfall possible across RI * Low risk for a few strong/severe storms Quite an anomalous system for mid July with amplifying mid level trough moving east from the Gt Lakes and closing off as it lifts into central/northern New Eng tonight. Strong forcing for ascent acting on tropical moisture plume will bring heavy rainfall to portions of SNE today. Hi-res and global guidance is in excellent agreement that the most prolific rainfall from this storm will be across VT. However, will see heavy rainfall amounts extending south across western New Eng. Surface low off the mid Atlc coast with an inverted trough extending to the north into SE NY. It appears this boundary will be a focus for heavy rainfall through the morning as it moves slowly E into western CT/MA. This is where the greatest risk for possible flash flooding will be this morning, especially from the Berkshires to western CT, mainly west of I-91 as heavy showers and embedded t- storms blossom and move north across this area. HREF indicating moderate probs of greater than 1"/hr rainfall rates in this region. Numerous showers and embedded t-storms will be moving east across rest of SNE today as shortwave energy rotates around the base of the trough and approaches from the SW and sfc low and boundary move eastward. Multiple CAMs are suggesting a secondary heavy rainfall max across RI today, which could produce street flooding and bring about rapid rises of creeks and streams and fast responding rivers. Locally heavy rainfall also expected in portions of eastern MA but not expecting significant impacts in this area. Regarding rainfall amounts, we expect the heaviest rain with potential for storm total amounts of 2-4 inches and locally higher amounts across the Berkshires to far western CT. Elsewhere, generally 1 to 2 inches expected with less across SE MA and especially Cape Cod, but locally 2+ inches possible across portions of RI. The other concern for today is the potential for a few strong to severe t-storms. 0-6km shear is increasing to 30-35 kt but instability may be a limiting factor. CAPES of 500-1000 J/kg are expected, possibly a bit higher in western New Eng. If the higher instability can be realized the potential exists for a few strong to severe storms with wind the main concern. However, always have to be watchful for spinups in tropical environments with increasing shear, especially near boundaries. Low level wind field is weak and helicity values are unimpressive, but 0-3km CAPE is decent and we have a boundary which could locally enhance low level shear. CSU machine learning probs are highlighting a very low TOR risk so will have to closely monitor radar for rotation. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... Tonight... Dry slot will be overspreading SNE from the south tonight leading to showers tapering off from south to north this evening. Mid level low lifts across central/northern New Eng and southern edge of the comma head could keep showers going into the overnight across northern and especially NW MA. Lows will be mostly in the 60s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Highlights... * Mainly and very warm Tue * Hot and sunny on Wednesday with somewhat drier conditions * Unsettled weather and humidity returns on Thursday Wednesday A brief period of dry weather for southern New England on Wednesday as a relatively dry air mass characterized by PWATs ranging from 1 to 1.25 inches which is relatively low for mid-July. This will support abundant sunshine across southern New England on Wednesday with the exception of some diurnal cu. 925 hPa temps near 25 Celsius will support hot temperatures in the low 90s at the surface. With dewpoints only in the mid to upper 60s, the heat index will only be a degree or two higher on Wednesday afternoon. Wednesday definitely looks to be the pick of the week for those who prefer sunshine. Thursday and Friday The dry spell is very short-lived as a moisture and humidity return to southern New England on Thursday. Deep southwest flow will advect of a plume of 1.75+ inch PWATs over the region. This will result in increasing cloud cover Thursday morning into Thursday afternoon. As an upper-level disturbance approaches from the west we may see some showers and thunderstorms by the mid-afternoon across the western areas before spreading east Thursday night into Friday. As short- wave energy associated with this disturbance lifts northeast over The Hudson River Valley Thursday night through Friday, southern New England is likely to receive another round of substantial rainfall. Won't dive into the where and how much just yet, but given soils are likely to be saturated from tonight and tomorrows heavy rainfall threat, we'll have to be on the lookout for flood/flash flood potential as we approach the end of the week. Given favorable antecedent conditions, WPC has placed portions of western MA and CT in a marginal risk for excessive rainfall for the Thursday/Friday time frame and a slight risk for the Friday/Saturday time frame. Next Weekend Broad cyclonic flow aloft with embedded short-waves will continue to support shower/thunderstorm chances over The Northeast next weekend. Details are vague at this time, so have leaned on NBM for guidance which appropriately places chance PoPs across the region. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Through 12z... IFR-LIFR stratus and patchy fog. Showers and embedded t-storms mainly focused across western MA and northern CT. Today...Moderate confidence. IFR-LIFR conditions with numerous showers and scattered t-storms moving across SNE. Improving to MVFR in the CT valley in the afternoon. Variable winds, mostly E/SE across eastern New Eng and shifting to N in the CT valley during the afternoon. Tonight...Moderate confidence. Gradual improvement from MVFR/IFR to VFR from SW to NE as showers lift to the north. Showers may linger across portion of N/NW MA overnight. Variable winds shift to the W/NW late overnight. BOS Terminal...Moderate confidence. IFR-LIFR cigs persisting through the day and may see vsbys drop to around 1 mile at times. Widespread showers develop mid/late morning and can't rule out a few embedded t-storms. Improving to MVFR then VFR 03-06z as winds shift to SW. BDL Terminal...Moderate confidence. Lowering to IFR with numerous showers and embedded t-storms through the morning, improving to MVFR in the afternoon and VFR this evening. Outlook /Tuesday through Friday/... Tuesday: VFR. Breezy. Slight chance SHRA. Tuesday Night through Wednesday: VFR. Wednesday Night: VFR. Isolated SHRA. Thursday: VFR. Scattered SHRA, isolated TSRA. Thursday Night: Mainly VFR, with areas MVFR possible. Breezy. Numerous SHRA, isolated TSRA. Friday: Mainly MVFR, with local IFR possible. Breezy. Numerous SHRA, isolated TSRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tranquil boating conditions persist through Monday with light winds and seas. The main impact will be areas of poor nighttime and morning visibility in areas of fog which could be dense at times. Showers and a few t-storms will also be moving into the waters Monday on moving northward Monday night. Outlook /Tuesday through Friday/... Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday Night through Wednesday Night: Winds less than 25 kt. Thursday: Winds less than 25 kt. Isolated rain showers. Thursday Night through Friday: Winds less than 25 kt. Seas locally approaching 5 ft. Scattered rain showers, isolated thunderstorms. && .HYDROLOGY... Rivers: For the latest river stage levels and forecasts, see the forecasts from the Northeast River Forecast. Larger rivers and smaller streams are expected to rise through today in the face of heavy rains. NERFC forecasts call for rises into the Minor Flood Category on most of the Connecticut River basins later Monday into Tuesday. We are most concerned about the Connecticut, Deerfield, Westfield, and Farmington Rivers to experience rises to near or over bankfull. Besides just local rainfall amounts reaching the rivers, rains falling upriver in the CT River basin in VT and NH will likely lead to additional rises even after heavy rains have ended. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Flood Watch through Tuesday morning for CTZ002>004. MA...Flood Watch through Tuesday morning for MAZ002>004-008>012-026. RI...Flood Watch through Tuesday morning for RIZ001>007. MARINE...None. && SYNOPSIS...KJC/RM NEAR TERM...KJC/RM SHORT TERM...KJC LONG TERM...Loconto/RM AVIATION...KJC/Loconto MARINE...KJC/Loconto HYDROLOGY...
Hazardous Weather Outlook National Weather Service Boston/Norton MA 410 AM EDT Mon Jul 10 2023 CTZ002>004-MAZ002>004-008>012-026-RIZ001>007-110815- Hartford CT-Tolland CT-Windham CT-Western Franklin MA- Eastern Franklin MA-Northern Worcester MA-Western Hampshire MA- Western Hampden MA-Eastern Hampshire MA-Eastern Hampden MA- Southern Worcester MA-Northern Middlesex MA-Northwest Providence RI- Southeast Providence RI-Western Kent RI-Eastern Kent RI-Bristol RI- Washington RI-Newport RI- 410 AM EDT Mon Jul 10 2023 ...FLOOD WATCH IN EFFECT THROUGH TUESDAY MORNING... This Hazardous Weather Outlook is for northern Connecticut, central Massachusetts, eastern Massachusetts, western Massachusetts, northern Rhode Island and southern Rhode Island. .DAY ONE...Today 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. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flood Watch. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. MAZ005>007-013>024-RIZ008-110815- Central Middlesex MA-Western Essex MA-Eastern Essex 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-Block Island RI- 410 AM EDT Mon Jul 10 2023 This Hazardous Weather Outlook is for eastern Massachusetts, northeastern Massachusetts, southeastern Massachusetts and southern Rhode Island. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. ANZ230>237-250-251-254>256-110815- 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- 410 AM EDT Mon Jul 10 2023 This Hazardous Weather Outlook is for Massachusetts and Rhode Island coastal waters. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. For more information on upcoming hazardous weather, please see the Area Forecast Discussion on our webpage for the latest forecast thinking. There is also our Enhanced Hazardous Weather Outlook at www.weather.gov/box/ehwo For the latest updates...please visit our webpage at www.weather.gov/boston You can follow us on Facebook at www.facebook.com/NWSBoston You can follow us on Twitter at @NWSBoston
Special Weather Statement
National Weather Service Boston/Norton MA
616 AM EDT Mon Jul 10 2023
CTZ002>004-101115-
Hartford CT-Tolland CT-Windham CT-
616 AM EDT Mon Jul 10 2023
...A strong thunderstorm will impact portions of southwestern
Windham, Tolland and Hartford Counties through 715 AM EDT...
At 615 AM EDT, Doppler radar was tracking a strong thunderstorm over
Glastonbury, moving north at 25 mph.
HAZARD...Minor flooding.
SOURCE...Radar indicated.
IMPACT...Minor nuisance flooding of typically flood prone areas.
ADDITIONAL DETAILS... Periods of heavy rainfall are forecast to
continue this morning and afternoon. If prolonged heavy rainfall
rates continue to occur over this area, a flash flood warning may be
issued.
Locations impacted include...
Hartford, New Britain, West Hartford, Manchester, East Hartford,
Enfield, Southington, Glastonbury, Newington, Vernon, Windsor,
Wethersfield, Mansfield, South Windsor, Farmington, Windham,
Simsbury, Bloomfield, Berlin and Rocky Hill.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.
This storm may intensify and become severe. Stay tuned to your local
media for updates and possible warnings.
&&
LAT...LON 4195 7290 4197 7222 4166 7216 4171 7224
4169 7227 4167 7227 4165 7231 4164 7250
4165 7253 4164 7257 4164 7266 4162 7285
TIME...MOT...LOC 1015Z 177DEG 23KT 4168 7256
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH
RMSpecial Weather Statement
National Weather Service Boston/Norton MA
619 AM EDT Mon Jul 10 2023
CTZ002-MAZ002-003-008>011-101115-
Hartford CT-Western Franklin MA-Western Hampshire MA-
Western Hampden MA-Eastern Hampden MA-Eastern Franklin MA-
Eastern Hampshire MA-
619 AM EDT Mon Jul 10 2023
...A strong thunderstorm will impact portions of northwestern
Hartford, Hampshire, northwestern Franklin and western Hampden
Counties through 715 AM EDT...
At 619 AM EDT, Doppler radar was tracking a strong thunderstorm over
Hartland, or 11 miles southwest of Westfield, moving north at 15 mph.
HAZARD...Minor flooding.
SOURCE...Radar indicated.
IMPACT...Minor nuisance flooding of typically flood prone areas.
ADDITIONAL DETAILS...Periods of heavy rainfall are forecast to
continue this morning and afternoon. If prolonged heavy
rainfall rates continue to occur over this area, a flash
flood warning may be issued.
Locations impacted include...
Springfield, Chicopee, Westfield, Holyoke, Northampton, Agawam, West
Springfield, Greenfield, Deerfield, South Hadley, Easthampton,
Longmeadow, Suffield, Monroe, Granby, Southwick, Montague,
Southampton, Hadley and East Granby.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Get indoors when you hear thunder. Do not resume outdoor activities
until at least 30 minutes after the storm has passed.
This storm may intensify and become severe. Stay tuned to your local
media for updates and possible warnings.
&&
LAT...LON 4225 7300 4231 7300 4231 7302 4239 7301
4263 7295 4266 7295 4267 7298 4270 7295
4270 7298 4274 7297 4273 7254 4196 7261
4195 7289 4197 7289 4197 7303 4204 7301
4204 7303 4214 7304
TIME...MOT...LOC 1019Z 187DEG 14KT 4204 7294
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH
RMSpecial Weather Statement
National Weather Service Boston/Norton MA
714 AM EDT Mon Jul 10 2023
MAZ017-018-020-RIZ001-002-004>007-101245-
Northern Bristol MA-Southern Bristol MA-Western Plymouth MA-
Northwest Providence RI-Bristol RI-Washington RI-Eastern Kent RI-
Newport RI-Southeast Providence RI-
714 AM EDT Mon Jul 10 2023
...A strong thunderstorm will impact portions of west central
Plymouth, central Bristol, northeastern Washington, northeastern
Newport, eastern Kent, eastern Providence and Bristol Counties
through 845 AM EDT...
At 714 AM EDT, Doppler radar was tracking a strong thunderstorm over
Providence, moving north at 25 mph.
HAZARD...Minor flooding.
SOURCE...Radar indicated.
IMPACT...Minor nuisance flooding of typically flood prone areas near
Providence and Fall River.
ADDITIONAL DETAILS...Periods of heavy rainfall are forecast to
continue this morning and afternoon. If prolonged heavy rainfall
rates continue to occur over these areas, a flash flood warning may
be issued.
Locations impacted include...
Providence, Fall River, Warwick, Cranston, Pawtucket, Taunton, East
Providence, Dartmouth, Cumberland, North Providence, West Warwick,
Johnston, North Attleborough, North Kingstown, Bristol, Attleboro,
Smithfield, Lincoln, Central Falls and Norton.
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 4158 7122 4164 7122 4159 7128 4171 7116
4173 7122 4159 7134 4166 7135 4164 7134
4163 7133 4171 7129 4179 7137 4165 7136
4169 7145 4161 7141 4160 7137 4161 7153
4197 7150 4192 7099 4156 7100
TIME...MOT...LOC 1114Z 188DEG 22KT 4183 7140
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH
RMSpecial Weather Statement
National Weather Service Boston/Norton MA
722 AM EDT Mon Jul 10 2023
MAZ002-003-008>011-101245-
Western Franklin MA-Western Hampshire MA-Western Hampden MA-
Eastern Hampden MA-Eastern Franklin MA-Eastern Hampshire MA-
722 AM EDT Mon Jul 10 2023
...A strong thunderstorm will impact portions of Hampshire,
northwestern Franklin and western Hampden Counties through 845 AM
EDT...
At 721 AM EDT, Doppler radar was tracking a strong thunderstorm over
Russell, or near Westfield, moving north at 25 mph.
HAZARD...Minor flooding.
SOURCE...Radar indicated.
IMPACT...Minor nuisance flooding of typically flood prone areas.
ADDITIONAL DETAILS...Periods of heavy rainfall are forecast to
continue this morning and afternoon. If prolonged heavy rainfall
rates continue to occur over these areas, a flash flood warning may
be issued.
Locations impacted include...
Springfield, Chicopee, Westfield, Holyoke, Northampton, Agawam, West
Springfield, Greenfield, Deerfield, South Hadley, Easthampton,
Longmeadow, Monroe, Southwick, Montague, Southampton, Hadley,
Sunderland, Hatfield and Williamsburg.
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 4244 7300 4252 7297 4256 7298 4263 7295
4266 7295 4266 7298 4268 7299 4269 7296
4270 7295 4270 7299 4274 7299 4272 7256
4204 7258 4205 7301
TIME...MOT...LOC 1121Z 188DEG 21KT 4212 7288
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH
RMThe Albany radar (KENX), 94 km away, was scanning. The volume nearest the first event began at 12:36 UTC.
11 flood, 4 flash flood. Local standard time, as filed.
In Chester, Blandford Rd at Rt 20 was closed due to flooding.
In Williamsburg, a section of Rt 9 had significant street flooding.
In Ashfield, Conway Rd was flooded.
In Conway, North Poland Rd at Rt 116 was flooded up to doors of cars.
In Williamsburg, Ashfield Rd was flooded up to windows of homes with rescues in progress.
In Douglas, Gilboa Rd has significant street flooding.
In Northampton, Meadow St was flooded and closed.
In Worcester, the area of 86 Southwest was flooded with 4 cars stuck in flood waters.
In Fall River, there were cars stuck in flood waters at the intersection of Pleasant St and Quequechan St.
In Plainville, Grant St was flooded and impassable.
In Heath, a basement was flooded on Ed Clark Rd.
In Fall River, Plymouth Ave was flooded and impassable with a car stuck.
In Everett, Air Force Rd was closed due to flooding.
In Salem, Pearl St bridge was closed due to flooding.
In Rutlant, Rt 56 at Vista Circle was flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Massachusetts in 2023Every state in 2023This day in weather historyWarnings in Massachusetts, July 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1117552, 1117588, 1117591, 1117556, 1117559, 1117592, 1117593, 1117563, 1117567, 1117595, 1117597, 1117599, 1117601, 1117602, 1117603.