Alert archive / Connecticut / Flash Flood Warnings in 2021

Flash Flood Warning 17, NWS Albany, NY

July 18, 2021Northwest Hills Planning Region, Connecticut

NWS Albany, NY issued this flash flood warning at Jul 18, 2021, 1:02 AM EDT for Northwest Hills 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: Jul 18, 2021, 1:02 AM EDT (05:02 UTC)
Expired: Jul 18, 2021, 4:15 AM EDT
In force: 3 hr
Issued by: NWS Albany, NY
Area: Storm-based polygon
Flood severity: None

County Northwest Hills Planning Region, CT

The radar

The Brookhaven radar (KOKX), 84 km from the middle of the area, began a volume at 05:05 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 00:00Z, 5.0 hours before the alert went out and 84 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: 1431 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 988 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

As transmitted.

000 
WGUS51 KALY 180502
FFWALY
CTC005-180815-
/O.NEW.KALY.FF.W.0017.210718T0502Z-210718T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Albany NY
102 AM EDT Sun Jul 18 2021

The National Weather Service in Albany has issued a

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

* Until 415 AM EDT.

* At 102 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 1.5 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...
  Torrington, Thomaston, Litchfield, Oakville, Northwest Harwinton,
  Terryville, Woodbury Center, Watertown, Plymouth, Woodbury,
  Harwinton, Bethlehem, Morris, Bantam, Northfield, East Morris,
  Reynolds Bridge, Delano Field, Bethlehem Village and Plymouth
  Green.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4151 7327 4175 7325 4180 7302 4164 7298
      4163 7300 4163 7302 4161 7302 4162 7304
      4161 7306 4159 7306 4159 7308 4157 7309
      4156 7315 4156 7316 4151 7316 4151 7320
      4151 7324

FLASH FLOOD...RADAR INDICATED

$$

bew

1 follow-up statement

570 
WGUS71 KALY 180806
FFSALY

Flash Flood Statement
National Weather Service Albany NY
406 AM EDT Sun Jul 18 2021

CTC005-180816-
/O.EXP.KALY.FF.W.0017.000000T0000Z-210718T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Litchfield CT-
406 AM EDT Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 415 AM EDT EARLY THIS MORNING 
FOR SOUTHEASTERN LITCHFIELD 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 1200 PM EDT Sunday for 
portions of northwestern Connecticut, western Massachusetts, east 
central New York and southern Vermont.

LAT...LON 4151 7327 4175 7325 4180 7302 4164 7298
      4163 7300 4163 7302 4161 7302 4162 7304
      4161 7306 4159 7306 4159 7308 4157 7309
      4156 7315 4156 7316 4151 7316 4151 7320
      4151 7324

$$

bew

The office that day

Everything else NWS Albany, NY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 17, 8:40 PM EDT	Severe Thunderstorm Warning	ALY	Northwest Hills Planning Region	65 min
Jul 17, 9:12 PM EDT	Areal Flood Advisory	ALY	Northwest Hills Planning Region	3 hr
Jul 17, 9:23 PM EDT	Special Weather Statement	ALY		37 min
Jul 17, 9:47 PM EDT	Special Weather Statement	ALY		28 min
Jul 17, 10:46 PM EDT	Flash Flood Warning	ALY	Northwest Hills Planning Region	2 hr
Jul 17, 11:33 PM EDT	River Flood Warning	ALY	Northwest Hills Planning Region	21 days
Jul 18, 12:28 AM EDT	Special Weather Statement	ALY		32 min
Jul 18, 2:06 AM EDT	River Flood Warning	ALY	Northwest Hills Planning Region	4 days
Jul 18, 8:16 AM EDT	River Flood Warning	ALY	Greater Bridgeport Planning Region, Naugatuck Valley Planning Region	26 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.