Alert archive / Massachusetts / Flash Flood Warnings in 2021

Flash Flood Warning 38, NWS Boston/Norton, MA

September 2, 2021Hampden County, Hampshire County, Worcester County, Massachusetts; Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Sep 2, 2021, 7:25 AM EDT for Hampden County, Hampshire County, Worcester County, Massachusetts; Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut. It was in force for 6 hr. 8 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
Sep 2, 2021, 7:25 AM EDT (11:25 UTC)
Expired
Sep 2, 2021, 1:28 PM EDT
In force
6 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Hampden County, MA, Hampshire County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 112 km from the middle of the area, began a volume at 11:28 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
Sep 2, 7:46 AM EDTHEAVY RAIN 5.08Auburn, MA
Sep 2, 7:55 AM EDTFLOODAndover, CTHOP RIVER OUT OF ITS BANKS IN ANDOVER, WHICH FLOODED BUNKER HILL, LONG HILL AND PARKER BRIDGE ROADS.
Sep 2, 8:30 AM EDTFLOOD1 Ese Westfield, MATWITTER PHOTO OF POWERDERMILL BROOK OVERFLOWING ITS BANKS AND LEADING TO FLOODING ON GREENWOOD ST IN WESTFIELD.
Sep 2, 8:31 AM EDTHEAVY RAIN 5.5Monson, MA
Sep 2, 8:56 AM EDTHEAVY RAIN 6Canton, CT
Sep 2, 8:57 AM EDTHEAVY RAIN 5.6Willington, CT
Sep 2, 9:19 AM EDTFLOOD2 Ene Plainville, CTPHOTO OF HIGH WATER AT THE CWPM DUMPSTER SITE IN PLAINVILLE. HEIGHT OF FLOODWATERS ARE NEARLY UP TO THE BOTTOM OF A STOP SIGN.
Sep 2, 10:08 AM EDTHEAVY RAIN 5.5Mansfield Depot, CT

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

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 11.4 hours before the alert went out and 133 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 00:00Z on 2021-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 00:00Z on 2021-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.1939587897Sfc1 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
3 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
525 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

452 
WGUS51 KBOX 021125
FFWBOX
CTC003-013-015-MAC013-015-027-021915-
/O.NEW.KBOX.FF.W.0038.210902T1125Z-210902T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
725 AM EDT Thu Sep 2 2021

The National Weather Service in Norton has issued a

* Flash Flood Warning for...
  Hartford County in northern Connecticut...
  Tolland County in northern Connecticut...
  Windham County in northern Connecticut...
  Southern Worcester County in central Massachusetts...
  Hampden County in western Massachusetts...
  Southwestern Hampshire County in western Massachusetts...

* Until 315 PM EDT Thursday.

* At 725 AM EDT, gauge reports indicated heavy rain falling across 
  the warned area. Between 3 and 7 inches of rain have fallen. Flash 
  flooding is ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Heavy rain producing
           flash flooding.

  SOURCE...River and rain gauges reported.

  IMPACT...Life threatening flash flooding of streams, urban
           areas, highways, streets and underpasses. Many rivers
           and streams are still rising, and considerable poor
           drainage flooding remains.

* Some locations that will experience flash flooding include...
  Worcester, Springfield, Hartford, New Britain, West Hartford, 
  Bristol, Manchester, Chicopee, East Hartford, Enfield, 
  Southington, Westfield, Holyoke, Shrewsbury, Glastonbury, 
  Newington, Vernon, Windsor, Agawam and West Springfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4231 7300 4238 7307 4239 7307 4220 7269
      4230 7260 4217 7220 4219 7190 4235 7179
      4235 7164 4202 7153 4201 7180 4164 7180
      4171 7224 4159 7239 4164 7263 4156 7295
      4180 7302 4181 7295 4197 7289 4197 7303

FLASH FLOOD...GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

NB
2 follow-up statements
184 
WGUS71 KBOX 021410
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
1010 AM EDT Thu Sep 2 2021

CTC003-013-015-MAC013-015-027-021915-
/O.CON.KBOX.FF.W.0038.000000T0000Z-210902T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hartford CT-Tolland CT-Windham CT-Hampden MA-Hampshire MA-Worcester
MA-
1010 AM EDT Thu Sep 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 PM EDT THIS 
AFTERNOON FOR HARTFORD, TOLLAND, WINDHAM, SOUTHERN WORCESTER, 
HAMPDEN AND SOUTHWESTERN HAMPSHIRE COUNTIES...

At 1010 AM EDT, gauge reports indicated that heavy rain had fallen 
across the warned area. Between 4 and 6.5 inches of rain have 
fallen. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding.

SOURCE...River gauges reported.

IMPACT...Life threatening flash flooding of streams and small
         rivers, urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Worcester, Springfield, Hartford, New Britain, West Hartford, 
  Bristol, Manchester, Chicopee, East Hartford, Enfield, 
  Southington, Westfield, Holyoke, Shrewsbury, Glastonbury, 
  Newington, Vernon, Windsor, Agawam and West Springfield.

Several area rivers were rising towards or had crested above 
Moderate Flood Stage. This included the following rivers; the Mount 
Hope River at Warrenville, the Quinnipiac River at Southington, the 
Hockanum River at East Hartford, and the North Branch Park River in 
Hartford. Rivers that were in minor flood included the Quinebaug 
River at Quinebaug, and the Willimantic River at Coventry. There are 
likely other ungaged rivers and streams that are producing minor to 
moderate flooding in the warning area.

In addition, any areas of significant urban and poor drainage 
flooding may take several hours or more to fully recede.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4231 7300 4238 7307 4239 7307 4220 7269
      4230 7260 4217 7220 4219 7190 4235 7179
      4235 7164 4202 7153 4201 7180 4164 7180
      4171 7224 4159 7239 4164 7263 4156 7295
      4180 7302 4181 7295 4197 7289 4197 7303

FLASH FLOOD...GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

NB
088 
WGUS71 KBOX 021728
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
128 PM EDT Thu Sep 2 2021

CTC003-013-015-MAC013-015-027-021738-
/O.CAN.KBOX.FF.W.0038.000000T0000Z-210902T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hartford CT-Tolland CT-Windham CT-Hampden MA-Hampshire MA-Worcester
MA-
128 PM EDT Thu Sep 2 2021

...FLASH FLOOD WARNING FOR HARTFORD, TOLLAND AND WINDHAM COUNTIES 
HAS BEEN REPLACED WITH A FLOOD WARNING...

Across Northern Connecticut, most small rivers and streams are 
coming into crest or beginning to recede. While river flooding 
remains a threat through this afternoon, the threat of flash 
flooding has come to an end.

LAT...LON 4203 7301 4203 7281 4200 7282 4200 7277
      4203 7275 4201 7180 4164 7180 4171 7224
      4159 7239 4161 7248 4165 7251 4164 7263
      4156 7295 4164 7294 4164 7297 4180 7302
      4181 7295 4197 7289 4197 7303

$$

RC

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 9:13 PM EDTFlash Flood WarningBOXHampden10 hr
Sep 1, 9:24 PM EDTSpecial Marine WarningBOX66 min
Sep 1, 9:37 PM EDTFlash Flood WarningBOXWorcester10 hr
Sep 1, 10:01 PM EDTFlash Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk8 hr
Sep 1, 10:32 PM EDTFlash Flood WarningBOXBristol, Norfolk, Plymouth10 hr
Sep 1, 10:45 PM EDTSpecial Marine WarningBOX45 min
Sep 1, 10:57 PM EDTFlash Flood WarningBOXFranklin, Hampshire, Middlesex, Worcester8 hr
Sep 1, 11:02 PM EDTFlash Flood WarningBOXEssex, Middlesex8 hr
Sep 1, 11:21 PM EDTTornado WarningBOXBarnstable, Bristol, Dukes, Plymouth54 min
Sep 1, 11:24 PM EDTSpecial Marine WarningBOX66 min
Sep 1, 11:32 PM EDTSpecial Marine WarningBOX58 min
Sep 1, 11:32 PM EDTSpecial Marine WarningBOX58 min
Sep 1, 11:56 PM EDTTornado WarningBOXBarnstable, Dukes49 min
Sep 2, 12:08 AM EDTFlash Flood WarningBOXBarnstable, Dukes8 hr
Sep 2, 12:20 AM EDTSpecial Marine WarningBOX55 min
Sep 2, 12:22 AM EDTTornado WarningBOXDukes53 min
Sep 2, 12:25 AM EDTSpecial Marine WarningBOX65 min
Sep 2, 12:45 AM EDTTornado WarningBOXBarnstable, Dukes60 min
Sep 2, 1:07 AM EDTSpecial Marine WarningBOX83 min
Sep 2, 1:15 AM EDTTornado WarningBOXDukes28 min
Sep 2, 1:51 AM EDTRiver Flood WarningBOXWorcester31 hr
Sep 2, 1:56 AM EDTTornado WarningBOXBarnstable26 min
Sep 2, 2:34 AM EDTFlash Flood Warning Considerable damage threatBOXBristol, Plymouth6 hr
Sep 2, 3:42 AM EDTRiver Flood WarningBOXNorfolk, Suffolk11 hr
Sep 2, 5:14 AM EDTSpecial Marine WarningBOX46 min
Sep 2, 5:26 AM EDTFlash Flood Warning Considerable damage threatBOXBarnstable, Bristol, Dukes, Plymouth3 hr
Sep 2, 5:30 AM EDTRiver Flood WarningBOXMiddlesex22 hr
Sep 2, 5:49 AM EDTSpecial Marine WarningBOX42 min
Sep 2, 6:02 AM EDTFlash Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk3 hr
Sep 2, 6:14 AM EDTSpecial Marine WarningBOX25 min
Sep 2, 6:50 AM EDTAreal Flood WarningBOXFranklin, Hampden, Hampshire, Middlesex, Worcester6 hr
Sep 2, 7:04 AM EDTAreal Flood WarningBOXBristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk and 1 more11 hr
Sep 2, 7:43 AM EDTAreal Flood WarningBOXBristol, Norfolk, Plymouth, Worcester6 hr
Sep 2, 7:54 AM EDTAreal Flood WarningBOXBarnstable, Dukes, Plymouth6 hr
Sep 2, 8:14 AM EDTRiver Flood WarningBOXHampden, Hampshire13 hr
Sep 2, 8:20 AM EDTRiver Flood WarningBOXWorcester32 hr
Sep 2, 8:20 AM EDTRiver Flood WarningBOXMiddlesex, Worcester60 hr
Sep 2, 9:25 AM EDTRiver Flood WarningBOXBristol, Plymouth64 hr
Sep 2, 10:40 AM EDTSmall Craft AdvisoryBOX17 hr
Sep 2, 12:51 PM EDTAreal Flood WarningBOXFranklin, Hampden, Hampshire, Middlesex, Norfolk, Worcester6 hr
Sep 2, 1:28 PM EDTAreal Flood WarningBOXHampden6 hr
Sep 2, 1:42 PM EDTAreal Flood WarningBOXBristol, Norfolk, Plymouth, Worcester6 hr
Sep 2, 5:59 PM EDTRiver Flood WarningBOXEssex, Middlesex25 hr
Sep 2, 1:51 AM EDTRiver Flood WarningBOXCapitol Planning Region26 hr
Sep 2, 1:51 AM EDTRiver Flood WarningBOXCapitol Planning Region66 hr
Sep 2, 1:51 AM EDTRiver Flood WarningBOXCapitol Planning Region45 hr
Sep 2, 8:20 AM EDTRiver Flood WarningBOXSoutheastern Connecticut Planning Region53 hr

Nearby

Flash Flood Warnings in Massachusetts, 2021Flash Flood Warnings in Connecticut, 2021Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.