Alert archive / Massachusetts / Flash Flood Warnings in 2021

Flash Flood Warning 27, NWS Boston/Norton, MA

September 1, 2021Hampden County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Sep 1, 2021, 9:13 PM EDT for Hampden County, Massachusetts. It was in force for 10 hr. 1 report 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 1, 2021, 9:13 PM EDT (01:13 UTC)
Expired
Sep 2, 2021, 7:00 AM EDT
In force
10 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

County Hampden County, MA

The radar

The Albany radar (KENX), 123 km from the middle of the area, began a volume at 01:17 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, 2:08 AM EDTFLOOD2 Ssw Southwick, MAROADWAY FLOODED AND IMPASSABLE NEAR THE INTERSECTION OF US RTE 202 AND MA 168.

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, 1.2 hours before the alert went out and 111 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, 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.

724 
WGUS51 KBOX 020113
FFWBOX
MAC013-020900-
/O.NEW.KBOX.FF.W.0027.210902T0113Z-210902T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
913 PM EDT Wed Sep 1 2021

The National Weather Service in Norton has issued a

* Flash Flood Warning for...
  Hampden County in western Massachusetts...

* Until 500 AM EDT Thursday.

* At 913 PM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 1 and 1.5 inches of rain have fallen. 
  Additional rainfall amounts of 2 to 5 inches are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Springfield, Chicopee, Westfield, Holyoke, Agawam, West 
  Springfield, Ludlow, South Hadley, Longmeadow, East Longmeadow, 
  Belchertown, Wilbraham, Palmer, Granby, Southwick, Sturbridge, 
  Monson, Southampton and Hadley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4204 7305 4215 7307 4214 7303 4231 7300
      4234 7290 4224 7291 4224 7281 4218 7269
      4229 7261 4228 7261 4223 7262 4223 7240
      4219 7240 4224 7222 4219 7226 4216 7213
      4203 7214 4204 7275 4200 7282 4204 7281

FLASH FLOOD...RADAR INDICATED

$$

HF
2 follow-up statements
021 
WGUS71 KBOX 020542
FFSBOX

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

MAC013-020900-
/O.CON.KBOX.FF.W.0027.000000T0000Z-210902T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-
142 AM EDT Thu Sep 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 AM EDT EARLY THIS 
MORNING FOR HAMPDEN COUNTY...

At 142 AM EDT, trained weather spotters reported heavy rain across 
the warned area. Between 2 and 4 inches of rain have fallen. 
Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area. Flash flooding is ongoing.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Trained spotters reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Springfield, Chicopee, Westfield, Holyoke, Agawam, West 
  Springfield, Ludlow, South Hadley, Longmeadow, East Longmeadow, 
  Belchertown, Wilbraham, Palmer, Granby, Southwick, Sturbridge, 
  Monson, Southampton and Hadley.

At 118 AM in Southwick Massachusetts, a trained spotter reported 
that Kine Road is flooded and closed. A Brook is out of its banks 
and flooding the roadway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4204 7305 4215 7307 4214 7303 4231 7300
      4234 7290 4224 7291 4224 7281 4218 7269
      4229 7261 4228 7261 4223 7262 4223 7240
      4219 7240 4224 7222 4219 7226 4216 7213
      4203 7214 4204 7275 4200 7282 4204 7281

FLASH FLOOD...OBSERVED

$$

Frank
821 
WGUS51 KBOX 020841
FFWBOX
MAC013-021100-
/O.EXT.KBOX.FF.W.0027.000000T0000Z-210902T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Norton has extended the

* Flash Flood Warning for...
  Hampden County in western Massachusetts...

* Until 700 AM EDT.

* At 441 AM EDT, The heavy rain has exited the region. However, 
  runoff from the widespread 2 to 5 inches of rain that has fallen 
  was causing some small streams to continue to rise. The Westfield 
  River at Huntington and the Mill River have gone into flood. In 
  addition, residual runoff will result in some roads being flooded 
  and impassable into the morning commute.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Springfield, Chicopee, Westfield, Holyoke, Agawam, West 
  Springfield, Ludlow, South Hadley, Longmeadow, East Longmeadow, 
  Belchertown, Wilbraham, Palmer, Granby, Southwick, Sturbridge, 
  Monson, Southampton and Hadley.

LAT...LON 4204 7305 4215 7307 4214 7303 4231 7300
      4234 7290 4224 7291 4224 7281 4218 7269
      4229 7261 4228 7261 4223 7262 4223 7240
      4219 7240 4224 7222 4219 7226 4216 7213
      4203 7214 4204 7275 4200 7282 4204 7281

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Frank

The office that day

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

IssuedProductOfficeCountiesLasted
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, 7:25 AM EDTFlash Flood Warning Considerable damage threatBOXHampden, Hampshire, Worcester6 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

Nearby

Flash Flood Warnings in Massachusetts, 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.