Alert archive / Connecticut / Flash Flood Warnings in 2017

Flash Flood Warning 21, NWS Albany, NY

September 5, 2017Northwest Hills Planning Region, Connecticut

NWS Albany, NY issued this flash flood warning at Sep 5, 2017, 7:29 PM 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
Sep 5, 2017, 7:29 PM EDT (23:29 UTC)
Expired
Sep 5, 2017, 10:30 PM 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), 88 km from the middle of the area, began a volume at 23:30 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, 11.5 hours before the alert went out and 88 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 2017-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 217 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 2017-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 square meters per square second.19395878Sfc1 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
217 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
902 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

099 
WGUS51 KALY 052329
FFWALY
CTC005-060230-
/O.NEW.KALY.FF.W.0021.170905T2329Z-170906T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Albany NY
729 PM EDT TUE SEP 5 2017

The National Weather Service in Albany has issued a

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

* Until 1030 PM EDT

* At 727 PM EDT, Doppler radar indicates another round of 
  thunderstorms producing heavy rain moving across the warned area. 
  Up to 2 to 3 inches of rain have already fallen. Flash flooding is 
  expected to begin shortly.

* Some locations that will experience flooding include...
  New Milford, New Preston, Woodbury Center, Gaylordsville, Woodbury,
  Bethlehem, Washington, Morris, Roxbury, Bridgewater, Bantam,
  Hotchkissville, Candlewood Trails, Pomeraug, Lower Merryall, Marble
  Dale, Bulls Bridge, Upper Merryall, Erickson Corner and Dempsey
  Landing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report flooding to the National Weather Service by email at
ALB.stormreport@noaa.gov...
On Facebook at www.facebook.com/nwsalbany or twitter @nwsalbany.

&&

LAT...LON 4149 7337 4151 7339 4149 7344 4152 7344
      4163 7350 4165 7349 4166 7349 4167 7352
      4172 7351 4173 7315 4156 7312 4156 7316
      4152 7316 4151 7321 4151 7332 4148 7333
      4148 7335

$$

IAA
1 follow-up statement
407 
WGUS71 KALY 060223
FFSALY

Flash Flood Statement
National Weather Service Albany NY
1023 PM EDT TUE SEP 5 2017

CTC005-060232-
/O.EXP.KALY.FF.W.0021.000000T0000Z-170906T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Litchfield CT-
1023 PM EDT TUE SEP 5 2017

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN LITCHFIELD COUNTY WILL
EXPIRE AT 1030 PM EDT...

The heavy rain has ended. Potential flash flooding is no longer 
expected to pose a threat. 

LAT...LON 4149 7337 4151 7339 4149 7344 4152 7344
      4163 7350 4165 7349 4166 7349 4167 7352
      4172 7351 4173 7315 4156 7312 4156 7316
      4152 7316 4151 7321 4151 7332 4148 7333
      4148 7335

$$

TAW

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 3:48 PM EDTSpecial Weather StatementALY27 min
Sep 5, 4:13 PM EDTSpecial Weather StatementALY32 min
Sep 5, 4:45 PM EDTSpecial Weather StatementALY60 min
Sep 5, 5:00 PM EDTSevere Thunderstorm WarningALYNorthwest Hills Planning Region60 min
Sep 5, 6:00 PM EDTAreal Flood AdvisoryALYNorthwest Hills Planning Region3 hr
Sep 5, 7:37 PM EDTSevere Thunderstorm WarningALYNorthwest Hills Planning Region53 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.