Alert archive / Massachusetts / Flash Flood Warnings in 2020

Flash Flood Warning 7, NWS Boston/Norton, MA

July 6, 2020Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Jul 6, 2020, 8:01 PM EDT for Hampden County, Hampshire County, Massachusetts. It was in force for 109 min. 5 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 6, 2020, 8:01 PM EDT (00:01 UTC)
Expired
Jul 6, 2020, 9:50 PM EDT
In force
109 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Hampden County, MA, Hampshire County, MA

The radar

The Boston radar (KBOX), 123 km from the middle of the area, began a volume at 00:02 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
Jul 6, 8:15 PM EDTFLOODEasthampton, MAPARK STREET FLOOD AND IMPASSABLE
Jul 6, 8:23 PM EDTFLOODEasthampton, MAGARFIELD AVE FOODED OUT
Jul 6, 8:28 PM EDTFLOODEasthampton, MAMANHOLE COVER POPPING OFF ON SEVERAL SIDE STREETS OFF PARK STREET
Jul 6, 8:30 PM EDTFLASH FLOODLudlow, MANUMEROUS STREETS FLOODED WITH UP TO 3 FEET OF WATER. MANY RESCUED FROM CARS STUCK IN FLOOD WATERS.
Jul 6, 9:02 PM EDTFLOODSpringfield, MABASEMENTS FLOODING ON BAY STREET

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, 0.0 hours before the alert went out and 116 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 2020-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 2020-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2994 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

021 
WGUS51 KBOX 070001
FFWBOX
MAC013-015-070300-
/O.NEW.KBOX.FF.W.0007.200707T0001Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
801 PM EDT Mon Jul 6 2020

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  South central Hampshire County in western Massachusetts...
  Eastern Hampden County in western Massachusetts...

* Until 1100 PM EDT.

* At 801 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to one inch of rain has
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  Springfield, Chicopee, Enfield, Westfield, Holyoke, Northampton,
  Agawam, West Springfield, Ludlow, South Hadley, Easthampton,
  Longmeadow, East Longmeadow, Wilbraham, Stafford, Somers, Monson,
  Granby, Southampton and Hampden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4233 7270 4203 7225 4203 7257 4221 7277

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

Frank
6 follow-up statements
464 
WGUS71 KBOX 070018
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
818 PM EDT Mon Jul 6 2020

MAC013-015-070300-
/O.CON.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampshire MA-Hampden MA-
818 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
SOUTH CENTRAL HAMPSHIRE AND EASTERN HAMPDEN COUNTIES...

At 815 PM EDT, trained weather spotters reported thunderstorms 
producing torrential rain. A trained spotter in Easthampton reported 
2.14 inches of rainfall in the past 30 minutes. Flash flooding is 
ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained weather spotters.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Springfield, Chicopee, Enfield, Westfield, Holyoke, Northampton,
Agawam, West Springfield, Ludlow, South Hadley, Easthampton,
Longmeadow, East Longmeadow, Wilbraham, Stafford, Somers, Monson,
Granby, Southampton and Hampden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4233 7270 4203 7225 4203 7257 4221 7277

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

Frank
556 
WGUS71 KBOX 070042
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
842 PM EDT Mon Jul 6 2020

MAC013-015-070300-
/O.CON.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampshire MA-Hampden MA-
842 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
SOUTH CENTRAL HAMPSHIRE AND EASTERN HAMPDEN COUNTIES...

At 838 PM EDT, trained weather spotters reported thunderstorms 
producing heavy rain and flash flooding. At 819 PM, Easthampton 
reported Garfield Avenue was flooded out near Park Street. In 
addition, at 828 PM trained spotters reported several manhole covers 
were popping of on side streets just off park street in Easthampton.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained weather spotters.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Springfield, Chicopee, Enfield, Westfield, Holyoke, Northampton,
Agawam, West Springfield, Ludlow, South Hadley, Easthampton,
Longmeadow, East Longmeadow, Wilbraham, Stafford, Somers, Monson,
Granby, Southampton and Hampden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4233 7270 4203 7225 4203 7257 4221 7277

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

Frank
117 
WGUS71 KBOX 070104
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
904 PM EDT Mon Jul 6 2020

MAC015-070114-
/O.CAN.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampshire MA-
904 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL HAMPSHIRE COUNTY IS
CANCELLED...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 4203 7249 4216 7262 4222 7253 4203 7225

$$

MAC013-070300-
/O.CON.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-
904 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
SOUTHEASTERN HAMPDEN COUNTY...

At 904 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area.  Flash flooding is ongoing or expected
to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Springfield, Chicopee, Ludlow, East Longmeadow, Wilbraham, Stafford,
Somers, Monson, Hampden and Wales.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4203 7249 4216 7262 4222 7253 4203 7225

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-3 INCHES IN 1 HOUR

$$

Frank
971 
WGUS71 KBOX 070116
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
916 PM EDT Mon Jul 6 2020

MAC013-070300-
/O.CON.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-
916 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
SOUTHEASTERN HAMPDEN COUNTY...

At 915 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. As of 910 PM, a trained weather spotter 
in Ludlow reported 3.12 inches of rain in just 40 minutes! Flash 
flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Springfield, Chicopee, Ludlow, East Longmeadow, Wilbraham, Stafford,
Somers, Monson, Hampden and Wales.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4203 7249 4216 7262 4222 7253 4203 7225

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

Frank
455 
WGUS71 KBOX 070138
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
938 PM EDT Mon Jul 6 2020

MAC013-070300-
/O.CON.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-
938 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
SOUTHEASTERN HAMPDEN COUNTY...

At 936 PM EDT, Doppler radar indicated that the rainfall rates were 
diminishing across the region. However, spotter reports indicated 
that 2 to 3 inches of rain has fallen in this region over the 
past hour. Runoff may still result in flash flooding.

HAZARD...Flash flooding caused by earlier thunderstorms.

SOURCE...Spotter reports of earlier intense rainfall rates.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Springfield, Ludlow, East Longmeadow, Wilbraham, Monson and Hampden. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4204 7245 4213 7257 4219 7248 4207 7231

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

Frank
086 
WGUS71 KBOX 070150
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
950 PM EDT Mon Jul 6 2020

MAC013-070200-
/O.CAN.KBOX.FF.W.0007.000000T0000Z-200707T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-
950 PM EDT Mon Jul 6 2020

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN HAMPDEN COUNTY IS
CANCELLED...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed any remaining road closures.

LAT...LON 4204 7245 4213 7257 4219 7248 4207 7231

$$

Frank

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 8:33 PM EDTSpecial Weather StatementBOXHampden27 min
Jul 6, 8:45 PM EDTSpecial Weather StatementBOXHampden30 min

Nearby

Flash Flood Warnings in Massachusetts, 2020Every flash flood warning in 2020

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.