Alert archive / New Hampshire / Flash Flood Warnings in 2023

Flash Flood Warning 40, NWS Gray, ME

July 9, 2023Cheshire County, Hillsborough County, Sullivan County, New Hampshire

NWS Gray, ME issued this flash flood warning at Jul 9, 2023, 6:08 PM EDT for Cheshire County, Hillsborough County, Sullivan County, New Hampshire. 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 counties it named.

The facts

Issued: Jul 9, 2023, 6:08 PM EDT (22:08 UTC)
Expired: Jul 9, 2023, 9:53 PM EDT
In force: 4 hr
Issued by: NWS Gray, ME
Area: Storm-based polygon
Flood severity: None

Counties Cheshire County, NH, Hillsborough County, NH, Sullivan County, NH

The radar

The Boston radar (KBOX), 145 km from the middle of the area, began a volume at 22:11 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

Gray, ME (KGYX), launched 12:00Z, 10.1 hours before the alert went out and 172 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: 209 J/kg
Mixed-layer CIN: -53 J/kg
Mixed-layer LCL: 474 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 43 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Gray, ME wrote its last area forecast discussion before this flash flood warning went out at Jul 9, 3:59 PM EDT, 2 hours 9 minutes earlier.

Area forecast discussion, Jul 9, 3:59 PM EDT, 2 hours 9 minutes before

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Hazardous weather outlook, Jul 9, 3:52 PM EDT, 2 hours 16 minutes before

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In the hours before

Local storm report, Jul 9, 3:39 PM EDT, 2 hours 29 minutes before

Preliminary Local Storm Report
National Weather Service Gray ME
339 PM EDT Sun Jul 9 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0322 PM     Flash Flood      2 SW Swanzey            42.84N 72.32W
07/09/2023                   Cheshire           NH   Fire Dept/Rescue

            Corrects previous flood report from 2 SW
            Swanzey. Swanzey Lake Rd closed between Cram
            Hill Rd and Dunn Hill Rd due to water
            flowing over the roadway. Roadway beginning
            to washout.

&&

Local storm report, Jul 9, 3:45 PM EDT, 2 hours 23 minutes before

Preliminary Local Storm Report
National Weather Service Gray ME
345 PM EDT Sun Jul 9 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0344 PM     Flash Flood      2 SSW Swanzey           42.84N 72.31W
07/09/2023                   Cheshire           NH   Fire Dept/Rescue

            Rt 10 in the area of Pebble hill Rd
            impassible due to water flowing over the
            roadway.

&&

Local storm report, Jul 9, 3:49 PM EDT, 2 hours 19 minutes before

Preliminary Local Storm Report
National Weather Service Gray ME
349 PM EDT Sun Jul 9 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0344 PM     Flash Flood      2 SSW Swanzey           42.84N 72.31W
07/09/2023                   Cheshire           NH   Fire Dept/Rescue

            Corrects previous flash flood report from 2
            SSW Swanzey. Swanzey Lake Rd in the area of
            Pebble Hill Rd impassible due to water
            flowing over the roadway.

&&

Local storm report, Jul 9, 3:54 PM EDT, 2 hours 14 minutes before

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Local storm report, Jul 9, 4:09 PM EDT, 1 hour 59 minutes before

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Local storm report, Jul 9, 5:35 PM EDT, 33 minutes before

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The office that day

Everything else NWS Gray, ME issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 9, 3:45 PM EDT	Areal Flood Advisory	GYX	Franklin, Somerset	5 hr
Jul 8, 9:00 PM EDT	Flash Flood Warning	GYX	Hillsborough, Merrimack	2 hr
Jul 8, 9:10 PM EDT	Flash Flood Warning	GYX	Carroll, Coos, Grafton	2 hr
Jul 9, 2:37 AM EDT	Flood Watch	GYX	Cheshire, Coos, Grafton, Hillsborough, Merrimack, Sullivan	24 hr
Jul 9, 1:23 PM EDT	Areal Flood Advisory	GYX	Sullivan	2 hr
Jul 9, 1:36 PM EDT	Areal Flood Advisory	GYX	Cheshire	2 hr
Jul 9, 2:03 PM EDT	Flash Flood Warning	GYX	Cheshire	3 hr
Jul 9, 3:49 PM EDT	Flash Flood Warning Considerable damage threat	GYX	Cheshire	6 hr
Jul 9, 4:32 PM EDT	Areal Flood Advisory	GYX	Cheshire, Hillsborough	96 min

Nearby

Flash Flood Warnings in New Hampshire, 2023 Every flash flood warning in 2023

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.