Alert archive / Massachusetts / Areal Flood Warnings in 2021

Areal Flood Warning 21, NWS Boston/Norton, MA

July 18, 2021Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this areal flood warning at Jul 18, 2021, 10:37 PM EDT for Hampden County, Hampshire County, Massachusetts. It was in force for 4 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, 10:37 PM EDT (02:37 UTC)
Expired
Jul 19, 2021, 3:03 AM EDT
In force
4 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Hampden County, MA, Hampshire County, MA

The radar

The Albany radar (KENX), 105 km from the middle of the area, began a volume at 02:38 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, 2.6 hours before the alert went out and 92 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, Albany, NY at 00:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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, Albany, NY at 00:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
12 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
527 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

538 
WGUS41 KBOX 190237
FLWBOX

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Boston/Norton MA
1037 PM EDT Sun Jul 18 2021

MAC013-015-191430-
/O.NEW.KBOX.FA.W.0021.210719T0237Z-210719T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-Hampshire MA-
1037 PM EDT Sun Jul 18 2021

The National Weather Service in Norton has issued a

* Flood Warning for...
  Northwestern Hampden County in western Massachusetts...
  Southwestern Hampshire County in western Massachusetts...

* Until 1030 AM EDT Monday.

* At 1037 PM EDT, Due to rain earlier this evening, the West Branch 
  of the Westfield River at Huntington, Massachusetts was in flood 
  and was still rising.

* Some locations that will experience flooding include...
  Southampton, Huntington, Russell, Westhampton, Chester, Blandford 
  and Montgomery.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4218 7281 4218 7293 4225 7294 4233 7294
      4232 7288 4231 7281

$$

BW
1 follow-up statement
387 
WGUS81 KBOX 190703
FLSBOX

Flood Statement
National Weather Service Boston/Norton MA
303 AM EDT Mon Jul 19 2021

MAC013-015-190713-
/O.CAN.KBOX.FA.W.0021.000000T0000Z-210719T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hampden MA-Hampshire MA-
303 AM EDT Mon Jul 19 2021

...FLOOD WARNING IS CANCELLED FOR NORTHWESTERN HAMPDEN AND 
SOUTHWESTERN HAMPSHIRE COUNTIES...

Flood waters have receded. The West Branch of the Westfield River at 
Huntington, Massachusetts is no longer in flood. Please continue to 
heed remaining road closures.

LAT...LON 4218 7281 4218 7293 4225 7294 4233 7294
      4232 7288 4231 7281

$$

BW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 9:15 PM EDTSpecial Weather StatementBOXFranklin90 min
Jul 18, 9:26 PM EDTFlash Flood WarningBOXFranklin, Hampshire, Worcester3 hr
Jul 19, 12:26 AM EDTAreal Flood WarningBOXHampshire119 min
Jul 19, 12:32 AM EDTAreal Flood WarningBOXFranklin, Worcester118 min
Jul 19, 4:25 AM EDTAreal Flood WarningBOXHampden2 hr
Jul 19, 6:24 AM EDTRiver Flood WarningBOXHampden, Hampshire5 hr

Nearby

Areal Flood Warnings in Massachusetts, 2021Every areal 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.