Alert archive / Connecticut / Flash Flood Warnings in 2021

Flash Flood Warning 26, NWS Boston/Norton, MA

September 1, 2021Capitol Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Sep 1, 2021, 7:57 PM EDT for Capitol Planning Region, Connecticut. It was in force for 12 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 1, 2021, 7:57 PM EDT (23:57 UTC)
Expired
Sep 2, 2021, 8:00 AM EDT
In force
12 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

County Capitol Planning Region, CT

The radar

The Brookhaven radar (KOKX), 97 km from the middle of the area, began a volume at 23:58 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, 1:35 AM EDTFLOODManchester, CTPORTIONS OF EAST CENTER STREET FLOODED.
Sep 2, 1:50 AM EDTHEAVY RAIN 5.42Avon, CT
Sep 2, 4:01 AM EDTHEAVY RAIN 5.56Burlington, CT
Sep 2, 4:35 AM EDTHEAVY RAIN 5.4South Windsor, CT
Sep 2, 6:00 AM EDTFLOOD1 Wsw West Hartford, CTTWITTER PHOTO FROM WEST HARTFORD DEPT OF PUBLIC WORKS INDICATES FERN ST FROM MOUNTAIN RD TO NORTH MAIN ST WAS CLOSED DUE TO FLOODING
Sep 2, 6:29 AM EDTFLOOD2 Ene Bristol, CTNWS SAVI RELAYED BROADCAST MEDIA VIDEO OF STREET FLOODING AT INTERSECTION OF FARMINGTON AVE AND MIX ST. LIKELY FROM COPPER MINE BROOK OVERFLOWING ITS BANKS.
Sep 2, 6:30 AM EDTFLOOD1 Ene South Windsor, CTTHE PODUNK RIVER IN SOUTH WINDSOR OVERFLOWED ITS BANKS FLOODING THE FIRST FLOOR OF THE MILL ON THE RIVER RESTAURANT.
Sep 2, 7:05 AM EDTHEAVY RAIN 5.66Avon, CT

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 12.0 hours before the alert went out and 97 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, Brookhaven, NY at 12:00Z on 2021-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 joules per kilogram.LCLLFCEL10008507005003002001001 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, Brookhaven, NY at 12:00Z on 2021-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.19395878Sfc1 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
51 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1274 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

895 
WGUS51 KBOX 012357
FFWBOX
CTC003-013-020600-
/O.NEW.KBOX.FF.W.0026.210901T2357Z-210902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Norton has issued a

* Flash Flood Warning for...
  Hartford County in northern Connecticut...
  West Central Tolland County in northern Connecticut...

* Until 200 AM EDT Thursday.

* At 757 PM EDT, Doppler radar indicated mainly moderate intensity 
  rain across much of Hartford County. Torrential rain was observed 
  across southern New York and this will move into the warned area. 
  Between 1 to 1.5 inches of rain have fallen in the warned area, 
  and additional rainfall amounts of up to 4 inches are possible. 
  Flash flooding is ongoing or expected to begin shortly as 
  torrential rain overspreads the area.

  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...
  Hartford, New Britain, West Hartford, Bristol, Manchester, East 
  Hartford, Enfield, Southington, Glastonbury, Newington, Vernon, 
  Windsor, Wethersfield, South Windsor, Farmington, Simsbury, 
  Bloomfield, Berlin, Rocky Hill and Avon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 4197 7289 4197 7249 4181 7249 4159 7242
      4159 7247 4165 7251 4163 7271 4161 7272
      4159 7275 4158 7275 4156 7281 4157 7294
      4164 7294 4164 7298 4180 7302 4181 7295
      4184 7294 4185 7295 4189 7294 4190 7292

FLASH FLOOD...RADAR INDICATED

$$

AL
3 follow-up statements
737 
WGUS51 KBOX 020403
FFWBOX
CTC003-013-021200-
/O.EXT.KBOX.FF.W.0026.000000T0000Z-210902T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
1203 AM EDT Thu Sep 2 2021

The National Weather Service in Norton has extended the

* Flash Flood Warning for...
  Hartford County in northern Connecticut...
  West Central Tolland County in northern Connecticut...

* Until 800 AM EDT Thursday.

* At 1203 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 5 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 3 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Hartford, New Britain, West Hartford, Bristol, Manchester, East 
  Hartford, Enfield, Southington, Glastonbury, Newington, Vernon, 
  Windsor, Wethersfield, South Windsor, Farmington, Simsbury, 
  Bloomfield, Berlin, Rocky Hill and Avon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 4197 7289 4197 7249 4181 7249 4159 7242
      4159 7247 4165 7251 4163 7271 4161 7272
      4159 7275 4158 7275 4156 7281 4157 7294
      4164 7294 4164 7298 4180 7302 4181 7295
      4184 7294 4185 7295 4189 7294 4190 7292

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Frank
661 
WGUS71 KBOX 020535
FFSBOX

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

CTC003-013-021200-
/O.CON.KBOX.FF.W.0026.000000T0000Z-210902T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hartford CT-Tolland CT-
135 AM EDT Thu Sep 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING 
FOR HARTFORD AND WEST CENTRAL TOLLAND COUNTIES...

At 135 AM EDT, trained weather spotters reported heavy rain across 
the warned area. Between 2 and 5 inches of rain have fallen. 
Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area. Flash flooding is ongoing.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Trained spotters reported.

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

There have been several reports of street and basement flooding in 
the Farmington, Hartford and Bristol Connecticut areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 4197 7289 4197 7249 4181 7249 4159 7242
      4159 7247 4165 7251 4163 7271 4161 7272
      4159 7275 4158 7275 4156 7281 4157 7294
      4164 7294 4164 7298 4180 7302 4181 7295
      4184 7294 4185 7295 4189 7294 4190 7292

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Frank
103 
WGUS71 KBOX 020619
FFSBOX

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

CTC003-013-021200-
/O.CON.KBOX.FF.W.0026.000000T0000Z-210902T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hartford CT-Tolland CT-
219 AM EDT Thu Sep 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING 
FOR HARTFORD AND WEST CENTRAL TOLLAND COUNTIES...

At 219 AM EDT, The North Branch Park River gage indicated it was in 
moderate flood and continued to rise. In addition, the Burlington 
and Bunnell Brook is rising and approaching moderate flood and 
rising. This is dangerous situation especially at night.

Between 3 and 5 inches of rain have fallen. Additional rainfall 
amounts of 1 to 2 inches are possible in the warned area. Flash 
flooding is ongoing or expected to begin shortly.

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

SOURCE...Gauges reported.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 4197 7289 4197 7249 4181 7249 4159 7242
      4159 7247 4165 7251 4163 7271 4161 7272
      4159 7275 4158 7275 4156 7281 4157 7294
      4164 7294 4164 7298 4180 7302 4181 7295
      4184 7294 4185 7295 4189 7294 4190 7292

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

$$

Frank

Nearby

Flash 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.