Alert archive / Connecticut / Flash Flood Warnings in 2009

Flash Flood Warning 21, NWS Boston/Norton, MA

August 23, 2009Hampden County, Massachusetts; Capitol Planning Region, Connecticut

NWS Boston/Norton, MA issued this flash flood warning at Aug 23, 2009, 8:17 PM EDT for Hampden County, Massachusetts; Capitol Planning Region, Connecticut. It was in force for 65 min. 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 23, 2009, 8:17 PM EDT (00:17 UTC)
Expired: Aug 23, 2009, 9:22 PM EDT
In force: 65 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

Counties Capitol Planning Region, CT, Hampden County, MA

The radar

The Boston radar (KBOX), 102 km from the middle of the area, began a volume at 00:21 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

Albany, NY (KALY), launched 00:00Z, 0.3 hours before the alert went out and 139 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: 829 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 687 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: -0.2
Supercell composite: -1.1

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KBOX 240017
FFWBOX
CTC003-013-MAC013-240215-
/O.NEW.KBOX.FF.W.0021.090824T0017Z-090824T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
817 PM EDT SUN AUG 23 2009

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN HARTFORD COUNTY IN NORTHERN CONNECTICUT...
  NORTHWESTERN TOLLAND COUNTY IN NORTHERN CONNECTICUT...
  SOUTHEASTERN HAMPDEN COUNTY IN WESTERN MASSACHUSETTS...

* UNTIL 1015 PM EDT

* AT 808 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THE POTENTIAL FOR FLASH FLOODING FROM REPEATED AREAS OF HEAVY 
  SHOWERS AND THUNDERSTORMS IN EASTERN HAMPDEN COUNTY...NORTHWEST
  TOLLAND COUNTY...AND NORTHEAST HARTFORD COUNTIES.

  RADAR INDICATED RAINFALL RATES OF AS MUCH AS 2 TO 4 INCHES PER
  HOUR WITH THE STRONGEST STORMS.

  AMATEUR RADIO OPERATORS REPORTED SEVERAL FEET OF WATER ON 
  ROADWAYS IN SPRINGFIELD AND ALSO A CAR TRAPPED IN HIGH WATERS
  IN BELCHERTOWN.

EXCESSIVE RUNOFF FROM HEAVY RAIN WILL CAUSE RAPID FLOODING OF SMALL
STREAMS. FLOODING OF URBAN AREAS...INCLUDING ROADS AND UNDERPASSES IS
ALSO EXPECTED. DO NOT DRIVE THROUGH FLOODED ROADWAYS. THE WATER MAY 
BE TOO DEEP TO ALLOW VEHICLES TO CROSS SAFELY...OR THE ROADWAY MAY 
BE UNDERMINED. IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND 
IMMEDIATELY. RESIDENTS LIVING NEAR STREAMS AND CREEKS SHOULD TAKE 
IMMEDIATE ACTION TO PROTECT LIFE AND PROPERTY. 

&&

LAT...LON 4206 7258 4216 7239 4217 7224 4215 7219
      4215 7217 4213 7214 4204 7226 4200 7234
      4197 7240 4196 7250 4202 7252

$$
FIELD

1 follow-up statement

000 
WGUS71 KBOX 240122
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
922 PM EDT SUN AUG 23 2009

CTC003-013-MAC013-240129-
/O.CAN.KBOX.FF.W.0021.000000T0000Z-090824T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TOLLAND CT-HARTFORD CT-HAMPDEN MA-
922 PM EDT SUN AUG 23 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN
HAMPDEN...NORTHEASTERN HARTFORD AND NORTHWESTERN TOLLAND COUNTIES...

WHILE SOME SHOWERS STILL LINGERED OVER NORTHERN ROLLAND COUNRY AND 
SOUTHEASTERN HAMPDEN COUNTY AT 919 PM...RAINFALL RATES WERE MUCH 
LESS AND THE RISK OF FLASH FLOODING HAS DIMINISHED. 


LAT...LON 4206 7258 4216 7239 4217 7224 4215 7219
      4215 7217 4213 7214 4204 7226 4200 7234
      4197 7240 4196 7250 4202 7252

$$
FIELD

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 24, 6:42 PM EDT	Areal Flood Advisory	BOX	Essex, Middlesex	48 min

Nearby

Flash Flood Warnings in Connecticut, 2009 Flash Flood Warnings in Massachusetts, 2009 Every flash flood warning in 2009

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.