Alert archive / Connecticut / Flash Flood Warnings in 2018

Flash Flood Warning 34, NWS Boston/Norton, MA

September 25, 2018Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Sep 25, 2018, 8:12 PM EDT for Northeastern Connecticut Planning Region, Connecticut. It was in force for 2 hr. 9 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 25, 2018, 8:12 PM EDT (00:12 UTC)
Expired: Sep 25, 2018, 10:15 PM EDT
In force: 2 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), 81 km from the middle of the area, began a volume at 00:11 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
Sep 25, 8:14 PM EDT	FLOOD	Willimantic, CT	VALLEY AT BIRCH STREET CLOSED DUE TO FLOODING
Sep 25, 8:15 PM EDT	FLOOD	Willimantic, CT	MAIN STREET FLOODED AND IMPASSABLE. LAUNDROMAT HAS WATER COMING INTO THE STORE.
Sep 25, 8:15 PM EDT	FLOOD	Windham, CT	HORIZON AVE FLOODED AND MANHOLE COVERS DISPLACED
Sep 25, 8:46 PM EDT	FLOOD	Willimantic, CT	BRIDGE STREET FLOODED AND IMPASSABLE. WILLAMANTIC RIVER BELOW AND OUT OF IT'S BANKS.
Sep 25, 9:00 PM EDT	FLOOD	Windham, CT	JENNINGS LANE FLOODED AND IMPASSABLE. CLOSED DUE TO POSSIBLE WASHOUT.
Sep 25, 9:15 PM EDT	FLOOD	Willimantic, CT	SECTION OF WINDHAM ROAD (ROUTE 32) NEAR THE CENTER OF TOWN IS CLOSED DUE TO FLOODING.
Sep 25, 9:33 PM EDT	FLOOD	Windham, CT	SECTION OF INDIAN HOLLOW ROAD FLOODED AND IMPASSABLE WITH DEBRIS IN ROADWAY.
Sep 25, 9:58 PM EDT	FLOOD	Willimantic, CT	ASH STREET NEAR THE KINGSWOOD APARTMENTS FLOODED/IMPASSABLE AND PARTIAL ROAD WASHOUT
Sep 25, 10:05 PM EDT	HEAVY RAIN 6.18	Windham, 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 00:00Z, 0.2 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-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: 1035 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 453 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 318 m²/s²
0-3 km storm-relative helicity: 360 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 9.3

Open this sounding in Storm Lab

The text

As transmitted.

391 
WGUS51 KBOX 260012
FFWBOX
CTC013-015-260215-
/O.NEW.KBOX.FF.W.0034.180926T0012Z-180926T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
812 PM EDT TUE SEP 25 2018

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  Southern Windham County in northern Connecticut...
  East central Tolland County in northern Connecticut...

* Until 1015 PM EDT.

* At 811 PM EDT Doppler radar indicated heavy rain across the warned 
  area. Up to three inches of rain have already fallen. Flash 
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Mansfield, Windham, Willimantic, Killingly, Putnam, Brooklyn,
  Canterbury, Pomfret, Sprague, Chaplin, Hampton, Eastford, Scotland
  and Franklin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding will occur quickly, and
could be life threatening for those who try to drive through flooded
roads or underpasses. Find alternate routes. Those near small streams
need to get to higher ground immediately.

&&

LAT...LON 4165 7203 4166 7213 4166 7216 4171 7223
      4191 7206 4189 7184 4164 7202

$$

LEC/MHB

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 25, 8:32 PM EDT	Areal Flood Advisory	BOX	Northeastern Connecticut Planning Region	58 min
Sep 25, 10:06 PM EDT	Flash Flood Warning	BOX	Northeastern Connecticut Planning Region	93 min
Sep 25, 11:45 PM EDT	Areal Flood Advisory	BOX	Northeastern Connecticut Planning Region	2 hr
Sep 26, 1:52 AM EDT	Areal Flood Warning	BOX	Northeastern Connecticut Planning Region	3 hr

Nearby

Flash Flood Warnings in Connecticut, 2018 Every flash flood warning in 2018

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.