Alert archive / Connecticut / Flash Flood Warnings in 2011

Flash Flood Warning 18, NWS New York, NY

August 1, 2011Naugatuck Valley Planning Region, Connecticut

NWS New York, NY issued this flash flood warning at Aug 1, 2011, 6:26 PM EDT for Naugatuck Valley Planning Region, Connecticut. It was in force for 2 hr. 1 report 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 1, 2011, 6:26 PM EDT (22:26 UTC)
Expired
Aug 1, 2011, 8:30 PM EDT
In force
2 hr
Issued by
NWS New York, NY
Area
Storm-based polygon
Flood severity
None

County Naugatuck Valley Planning Region, CT

The radar

The Brookhaven radar (KOKX), 62 km from the middle of the area, began a volume at 22:28 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 1, 7:27 PM EDTFLASH FLOODAnsonia, CTSTREET AND BASEMENT FLOODING

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, 10.4 hours before the alert went out and 62 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 2011-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 529 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 2011-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
529 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
975 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

421 
WGUS51 KOKX 012226
FFWOKX
CTC009-020030-
/O.NEW.KOKX.FF.W.0018.110801T2226Z-110802T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE UPTON NY
ISSUED BY NATIONAL WEATHER SERVICE TAUNTON MA
626 PM EDT MON AUG 1 2011

THE NATIONAL WEATHER SERVICE IN UPTON NY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NEW HAVEN COUNTY IN SOUTHERN CONNECTICUT...
  THIS INCLUDES THE CITIES OF...WOLCOTT...WATERBURY...WALLINGFORD...
  NEW HAVEN...NAUGATUCK...MERIDEN...GUILFORD...

* UNTIL 830 PM EDT

* AT 621 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A CLUSTER OF THUNDERSTORMS PRODUCING LOCALLY TORRENTIAL RAINS IN
  CENTRAL CONNECTICUT. THE STORMS WERE CENTERED OVER
  WATERBURY...TRACKING SOUTHEAST. RAINFALL 
  RATES OF UP TO 3 INCHES IN AN HOUR ARE POSSIBLE WITH THE STORMS AS
  THEY MOVE THROUGH NEW HAVEN COUNTY.   AS A RESULT...URBAN FLASH
  FLOODING IS EXPECTED IN NEW HAVEN COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL WILL CAUSE RAPID FLOODING OF URBAN AREAS...
INCLUDING ROADS AND UNDERPASSES. FLOOD WATERS MAY BECOME DEEP ENOUGH
TO STRAND VEHICLES! AVOID FLOODED ROADWAYS!

&&

LAT...LON 4157 7294 4156 7286 4158 7280 4156 7277
      4143 7274 4143 7267 4133 7261 4126 7252
      4127 7263 4124 7270 4126 7276 4123 7287
      4128 7291 4129 7290 4129 7291 4122 7302
      4155 7316 4158 7307 4164 7303 4165 7294

$$

NMB
1 follow-up statement
795 
WGUS71 KOKX 020010
FFSOKX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
810 PM EDT MON AUG 1 2011

CTC009-020030-
/O.CON.KOKX.FF.W.0018.000000T0000Z-110802T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW HAVEN CT-
810 PM EDT MON AUG 1 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM EDT FOR
CENTRAL NEW HAVEN COUNTY...

AT 757 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWS THAT 
RAIN HAS ENDED AND NO ADDITIONAL RAINFALL IS FORECAST THE REST OF 
THE NIGHT OVER THE LOCAL AREA.  

FLOOD WATERS IN ANSONIA...DERBY...WOLCOTT...WATERBURY...PROSPECT AND 
SURROUNDING AREAS WILL CONTINUE TO RECEDE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4157 7294 4156 7286 4141 7284 4129 7291
      4128 7305 4146 7312 4158 7308 4158 7307
      4164 7303 4165 7294

$$

JST

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 12:42 PM EDTSpecial Weather StatementOKX48 min
Aug 1, 12:55 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region50 min
Aug 1, 1:44 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region46 min
Aug 1, 2:13 PM EDTSpecial Weather StatementOKX32 min
Aug 1, 2:27 PM EDTAreal Flood AdvisoryOKXGreater Bridgeport Planning Region3 hr
Aug 1, 2:36 PM EDTSpecial Weather StatementOKX39 min
Aug 1, 3:02 PM EDTSpecial Weather StatementOKX3 min
Aug 1, 4:40 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region65 min
Aug 1, 5:32 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region58 min
Aug 1, 5:34 PM EDTSevere Thunderstorm WarningOKXNaugatuck Valley Planning Region56 min
Aug 1, 5:38 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region52 min
Aug 1, 5:57 PM EDTSevere Thunderstorm WarningOKXLower Connecticut River Valley Planning Region63 min
Aug 1, 6:20 PM EDTSevere Thunderstorm WarningOKXNaugatuck Valley Planning Region40 min
Aug 1, 6:52 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region53 min
Aug 1, 6:55 PM EDTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region48 min

Nearby

Flash Flood Warnings in Connecticut, 2011Every flash flood warning in 2011

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.