Alert archive / Connecticut / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Boston/Norton, MA

July 17, 2021Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Jul 17, 2021, 4:14 PM EDT for Northeastern Connecticut Planning Region, Connecticut. It was in force for 5 hr. 4 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 17, 2021, 4:14 PM EDT (20:14 UTC)
Expired: Jul 17, 2021, 9:15 PM EDT
In force: 5 hr
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

County Northeastern Connecticut Planning Region, CT

The radar

The Boston radar (KBOX), 77 km from the middle of the area, began a volume at 20:16 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

Time	Report	Where	Remark
Jul 17, 5:31 PM EDT	FLASH FLOOD	Eastford, CT	SECTION OF PILFERSHIRE ROAD WASHED OUT
Jul 17, 6:07 PM EDT	FLOOD	Eastford, CT	SECTION OF OLD COLONY ROAD FLOODED AND IMPASSABLE
Jul 17, 6:43 PM EDT	FLASH FLOOD	Ashford, CT	BRIDGE WASHED OUT ON CUSHMAN ROAD
Jul 17, 7:30 PM EDT	FLASH FLOOD	Pomfret, CT	PARTIAL ROAD WASHOUT ON A SETION OF RTE 244

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, 8.2 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1203 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

771 
WGUS51 KBOX 172014
FFWBOX
CTC015-172315-
/O.NEW.KBOX.FF.W.0008.210717T2014Z-210717T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
414 PM EDT Sat Jul 17 2021

The National Weather Service in Norton has issued a

* Flash Flood Warning for...
  Northern Windham County in northern Connecticut...

* Until 715 PM EDT.

* At 414 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  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...
  Killingly, Putnam, Thompson, Woodstock, Ashford, Pomfret, Chaplin, 
  Hampton, Eastford and Union.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4184 7216 4186 7219 4194 7221 4196 7211
      4196 7210 4201 7183 4190 7181 4185 7190
      4181 7216

FLASH FLOOD...RADAR INDICATED

$$

BL

5 follow-up statements

321 
WGUS71 KBOX 172154
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
554 PM EDT Sat Jul 17 2021

CTC015-172315-
/O.CON.KBOX.FF.W.0008.000000T0000Z-210717T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Windham CT-
554 PM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT THIS 
EVENING FOR NORTHERN WINDHAM COUNTY...

At 554 PM EDT, trained spotters reported a section of Pilfershire 
Road in Eastford, CT being washed out at 531 PM. Doppler radar 
estimates 2 to 5 inches of rain have fallen. Additional rainfall 
amounts up to 1 inch are possible in the warned area. Flash flooding 
is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

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...
  Killingly, Putnam, Thompson, Woodstock, Ashford, Pomfret, Chaplin, 
  Hampton, Eastford and Union.

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.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4184 7216 4186 7219 4194 7221 4196 7211
      4196 7210 4201 7183 4190 7181 4185 7190
      4181 7216

FLASH FLOOD...OBSERVED

$$

BL

448 
WGUS51 KBOX 172228
FFWBOX
CTC015-180115-
/O.EXT.KBOX.FF.W.0008.000000T0000Z-210718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
628 PM EDT Sat Jul 17 2021

The National Weather Service in Norton has extended the

* Flash Flood Warning for...
  Northern Windham County in northern Connecticut...

* Until 915 PM EDT.

* At 628 PM EDT, a trained spotter in Pomfret, CT reported several 
  roadways washed out along with 4.95 inches of rain fallen so far 
  as of 615 PM. Between 2 and 5 inches of rain have fallen. 
  Additional rainfall amounts up to 1 inch are possible in the 
  warned area. Flash flooding is already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  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...
  Killingly, Putnam, Thompson, Woodstock, Ashford, Pomfret, Chaplin, 
  Hampton, Eastford and Union.

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.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4184 7216 4186 7219 4194 7221 4196 7211
      4196 7210 4201 7183 4190 7181 4185 7190
      4181 7216

FLASH FLOOD...OBSERVED

$$

BL

939 
WGUS71 KBOX 172317 RRD
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
717 PM EDT Sat Jul 17 2021

CTC015-180115-
/O.CON.KBOX.FF.W.0008.000000T0000Z-210718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Windham CT-
717 PM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM EDT THIS 
EVENING FOR CENTRAL WINDHAM COUNTY...

At 717 PM EDT, a trained spotter in Pomfret, CT reported several 
roadways washed out along with 4.95 inches of rain fallen so far as 
of 615 PM. Between 2 and 5 inches of rain have fallen. Additional 
rainfall amounts up to 1 inch are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

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...
  Killingly, Putnam, Thompson, Woodstock, Ashford, Pomfret, Chaplin, 
  Hampton and Eastford.

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.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4184 7216 4186 7219 4194 7221 4194 7214
      4195 7207 4194 7191 4190 7181 4185 7190
      4181 7216

FLASH FLOOD...OBSERVED

$$

BL

637 
WGUS71 KBOX 172358 RRA
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
758 PM EDT Sat Jul 17 2021

CTC015-180115-
/O.CON.KBOX.FF.W.0008.000000T0000Z-210718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Windham CT-
758 PM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM EDT THIS 
EVENING FOR CENTRAL WINDHAM COUNTY...

At 758 PM EDT, a trained spotter in Pomfret, CT reported several 
roadways washed out along with 4.95 inches of rain fallen so far as 
of 615 PM. Between 2 and 5 inches of rain have fallen. Additional 
rainfall amounts up to 1 inch are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

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...
  Killingly, Putnam, Thompson, Woodstock, Ashford, Pomfret, Chaplin, 
  Hampton and Eastford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4184 7216 4186 7219 4193 7220 4194 7214
      4195 7207 4194 7191 4190 7189 4185 7190
      4181 7216

FLASH FLOOD...OBSERVED

$$

BL

530 
WGUS71 KBOX 180111 RRA
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
911 PM EDT Sat Jul 17 2021

CTC015-180121-
/O.EXP.KBOX.FF.W.0008.000000T0000Z-210718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Windham CT-
911 PM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 915 PM EDT THIS EVENING FOR 
CENTRAL WINDHAM COUNTY...

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

A Flash Flood Watch remains in effect until 600 AM EDT Sunday for 
portions of northern Connecticut and Massachusetts.

LAT...LON 4184 7216 4186 7219 4193 7220 4194 7214
      4195 7207 4194 7191 4190 7189 4185 7190
      4181 7216

$$

BL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 1:59 PM EDT	Special Weather Statement	BOX		46 min
Jul 17, 3:26 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	64 min
Jul 17, 3:47 PM EDT	Areal Flood Warning	BOX	Northeastern Connecticut Planning Region	118 min
Jul 17, 4:15 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	60 min
Jul 17, 4:18 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	57 min
Jul 17, 4:20 PM EDT	Special Weather Statement	BOX		40 min
Jul 17, 4:29 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	61 min
Jul 17, 4:38 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region	67 min
Jul 17, 4:58 PM EDT	Flash Flood Warning	BOX	Capitol Planning Region	2 hr
Jul 17, 5:21 PM EDT	Flash Flood Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	5 hr
Jul 17, 5:30 PM EDT	Flash Flood Warning	BOX	Northeastern Connecticut Planning Region	3 hr

Nearby

Flash Flood Warnings in Connecticut, 2021 Every 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.