Alert archive / Connecticut / Flash Flood Warnings in 2018

Flash Flood Warning 27, NWS Boston/Norton, MA

September 12, 2018Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Sep 12, 2018, 2:25 PM EDT for Northeastern Connecticut Planning Region, Connecticut. It was in force for 2 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: Sep 12, 2018, 2:25 PM EDT (18:25 UTC)
Expired: Sep 12, 2018, 4:30 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), 77 km from the middle of the area, began a volume at 18:24 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 12, 2:39 PM EDT	HEAVY RAIN 2.12	Moosup, CT	1 INCH IN ONE HOUR
Sep 12, 2:43 PM EDT	HEAVY RAIN 2.02	Sterling, CT
Sep 12, 3:01 PM EDT	HEAVY RAIN 2.53	Brooklyn, CT	1.23 INCHES IN 72 MINUTES
Sep 12, 4:33 PM EDT	HEAVY RAIN 2.11	East Killingly, 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, 6.4 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: 1040 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 495 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

276 
WGUS51 KBOX 121825
FFWBOX
CTC015-122030-
/O.NEW.KBOX.FF.W.0027.180912T1825Z-180912T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
225 PM EDT WED SEP 12 2018

The National Weather Service in Boston/Norton has issued a

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

* Until 430 PM EDT.

* At 224 PM EDT Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to two inches of rain have 
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Windham, Plainfield, Killingly, Brooklyn, Canterbury, Pomfret,
  Sterling, Sprague, Hampton, Scotland, Jewett City and Franklin.

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 4164 7196 4166 7213 4166 7216 4168 7219
      4171 7215 4190 7180 4164 7179 4165 7186
      4163 7196

$$

md

1 follow-up statement

700 
WGUS71 KBOX 122035
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
435 PM EDT WED SEP 12 2018

CTC015-122045-
/O.EXP.KBOX.FF.W.0027.000000T0000Z-180912T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Windham CT-
435 PM EDT WED SEP 12 2018

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN WINDHAM COUNTY HAS
EXPIRED...

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

LAT...LON 4164 7196 4166 7213 4166 7216 4168 7219
      4171 7215 4190 7180 4164 7179 4165 7186
      4163 7196

$$

md

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 12, 11:59 AM EDT	Areal Flood Advisory	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	3 hr
Sep 12, 3:10 PM EDT	Flash Flood Watch	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	16 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.