Alert archive / Connecticut / Flash Flood Warnings in 2017

Flash Flood Warning 20, NWS Boston/Norton, MA

August 2, 2017Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Aug 2, 2017, 4:44 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 2, 2017, 4:44 PM EDT (20:44 UTC)
Expired
Aug 2, 2017, 7:45 PM EDT
In force
3 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT

The radar

The Boston radar (KBOX), 107 km from the middle of the area, began a volume at 20:48 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.7 hours before the alert went out and 113 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 2017-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 823 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 2017-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.193958Sfc1 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
823 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
1051 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

941 
WGUS51 KBOX 022044
FFWBOX
CTC003-013-015-022345-
/O.NEW.KBOX.FF.W.0020.170802T2044Z-170802T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Taunton MA
444 PM EDT WED AUG 2 2017

The National Weather Service in Taunton has issued a

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

* Until 745 PM EDT

* At 443 PM EDT, Doppler radar indicated thunderstorms producing 
  torrential rain across north central Connecticut. Flash flooding 
  is expected to begin shortly, including rapid inundation of roads 
  and underpasses. Several locations have already picked up over 2 
  inches of rain in the past hour.

* Some locations that will experience flooding include...
  Hartford, Manchester, East Hartford, Glastonbury, Vernon, Windsor,
  Wethersfield, Mansfield, South Windsor, Windham, Ellington,
  Tolland, Windsor Locks, Coventry, East Windsor, Hebron, Willington,
  Columbia, Bolton and Ashford.

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 4193 7266 4194 7209 4174 7210 4172 7236
      4171 7265

$$

JWD
1 follow-up statement
839 
WGUS71 KBOX 022201
FFSBOX

Flash Flood Statement
National Weather Service Taunton MA
601 PM EDT WED AUG 2 2017

CTC003-013-015-022210-
/O.CAN.KBOX.FF.W.0020.000000T0000Z-170802T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Windham CT-Tolland CT-Hartford CT-
601 PM EDT WED AUG 2 2017

...THE FLASH FLOOD WARNING FOR WEST CENTRAL WINDHAM...CENTRAL TOLLAND
AND NORTHEASTERN HARTFORD COUNTIES IS CANCELLED...

As of 6 PM, the heavy rain has moved into southern Connecticut. Rain 
will continue into this evening, but flooding is no longer expected 
to pose a threat. Avoid flooded roadways.

&&

LAT...LON 4193 7266 4194 7209 4174 7210 4172 7236
      4171 7265

$$

JWD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 11:55 AM EDTFlash Flood WatchBOXCapitol Planning Region, Northeastern Connecticut Planning Region8 hr
Aug 2, 1:07 PM EDTSpecial Weather StatementBOX23 min
Aug 2, 1:11 PM EDTSevere Thunderstorm WarningBOXNortheastern Connecticut Planning Region49 min
Aug 2, 1:45 PM EDTSpecial Weather StatementBOX45 min
Aug 2, 2:45 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region45 min
Aug 2, 2:54 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region51 min
Aug 2, 3:10 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region50 min
Aug 2, 3:56 PM EDTSevere Thunderstorm WarningBOXNortheastern Connecticut Planning Region49 min
Aug 2, 4:56 PM EDTSpecial Weather StatementBOX49 min

Nearby

Flash Flood Warnings in Connecticut, 2017Every flash flood warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.