Alert archive / Connecticut / Flash Flood Warnings in 2018

Flash Flood Warning 22, NWS Boston/Norton, MA

August 7, 2018Capitol Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Aug 7, 2018, 9:35 PM EDT for Capitol Planning Region, Connecticut. It was in force for 94 min. 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
Aug 7, 2018, 9:35 PM EDT (01:35 UTC)
Expired
Aug 7, 2018, 11:09 PM EDT
In force
94 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

County Capitol Planning Region, CT

The radar

The Brookhaven radar (KOKX), 118 km from the middle of the area, began a volume at 01:37 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
Aug 7, 9:50 PM EDTFLASH FLOOD1 Ssw North Bloomfield, CT3 FEET OF WATER ON ROAD AT WALTS HILL
Aug 7, 10:26 PM EDTFLASH FLOOD1 Nne Windsor, CTSLEEPY HOLLOW ROAD AT PIERSON LANE CLOSED DUE TO FLOODING
Aug 7, 10:35 PM EDTFLASH FLOODWindsor, CTSIGNIFICANT STREET FLOODING ON HOLCOMB HILL ROAD
Aug 7, 10:35 PM EDTFLASH FLOODWindsor Locks, CTCENTER STREET BETWEEN SPRING AND ELM STREETS CLOSED DUE TO FLOODING
Aug 7, 10:41 PM EDTFLASH FLOODSimsbury, CTSECTION OF ROUTE 10 FLOODED OUT
Aug 7, 10:49 PM EDTHEAVY RAIN 4.67Windsor, CT
Aug 7, 11:05 PM EDTHEAVY RAIN 4.67Windsor, CT
Aug 7, 11:09 PM EDTHEAVY RAIN 3.47East Granby, 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, 1.6 hours before the alert went out and 118 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 00:00Z on 2018-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1768 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 00:00Z on 2018-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
1768 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
724 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

510 
WGUS51 KBOX 080135
FFWBOX
CTC003-080330-
/O.NEW.KBOX.FF.W.0022.180808T0135Z-180808T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
935 PM EDT TUE AUG 7 2018

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  North central Hartford County in northern Connecticut...

* Until 1130 PM EDT.

* At 933 PM EDT Doppler radar indicated thunderstorms producing 
  heavy rain across northern Hartford county. Over two inches of 
  rain has already fallen in the past hour with additional rainfall 
  expected. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Enfield, Windsor, South Windsor, Simsbury, Bloomfield, Avon,
  Suffield, Windsor Locks, Granby, East Windsor, Canton and East
  Granby.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4199 7258 4184 7259 4181 7288 4196 7288

$$

Nocera
1 follow-up statement
209 
WGUS71 KBOX 080309
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
1109 PM EDT TUE AUG 7 2018

CTC003-080319-
/O.CAN.KBOX.FF.W.0022.000000T0000Z-180808T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hartford CT-
1109 PM EDT TUE AUG 7 2018

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL HARTFORD COUNTY IS
CANCELLED...

The heavy rain has ended. Flood waters have receded...but please 
continue to heed any remaining road closures.

LAT...LON 4199 7258 4184 7259 4181 7288 4196 7288

$$

Frank

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 8:50 PM EDTAreal Flood AdvisoryBOXCapitol Planning Region55 min
Aug 8, 3:29 AM EDTHeat AdvisoryBOXCapitol Planning Region, Northeastern Connecticut Planning Region15 hr

Nearby

Flash Flood Warnings in Connecticut, 2018Every 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.