Alert archive / New Hampshire / Flash Flood Warnings in 2023

Flash Flood Warning 56, NWS Gray, ME

July 18, 2023Grafton County, New Hampshire

NWS Gray, ME issued this flash flood warning at Jul 18, 2023, 1:09 PM EDT for Grafton County, New Hampshire. 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 counties it named.

The facts

Issued: Jul 18, 2023, 1:09 PM EDT (17:09 UTC)
Expired: Jul 18, 2023, 4:15 PM EDT
In force: 3 hr
Issued by: NWS Gray, ME
Area: Storm-based polygon
Flood severity: None

County Grafton County, NH

The radar

The Burlington radar (KCXX), 125 km from the middle of the area, began a volume at 17:10 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, 5.2 hours before the alert went out and 353 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: 403 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 790 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.9

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 18, 11:57 AM EDT, 1 hour 12 minutes earlier.

Area forecast discussion, Jul 18, 11:57 AM EDT, 1 hour 12 minutes before

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Hazardous weather outlook, Jul 18, 2:16 AM EDT, 10 hours 53 minutes before

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In the hours before

Special weather statement, Jul 18, 12:27 PM EDT, 42 minutes before

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Special weather statement, Jul 18, 12:48 PM EDT, 21 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 18, 2:18 PM EDT	Areal Flood Advisory	GYX	Franklin, Oxford, Somerset	3 hr
Jul 18, 3:37 PM EDT	Special Weather Statement	GYX	Franklin	38 min
Jul 18, 4:06 PM EDT	Flash Flood Warning	GYX	Somerset	3 hr
Jul 18, 4:22 PM EDT	Flash Flood Warning	GYX	Franklin, Somerset	3 hr
Jul 18, 4:51 PM EDT	Special Weather Statement	GYX	Somerset	39 min
Jul 18, 4:58 PM EDT	Severe Thunderstorm Warning	GYX	Androscoggin, Franklin, Oxford	47 min
Jul 18, 5:09 PM EDT	Flash Flood Warning	GYX	Franklin, Oxford	3 hr
Jul 18, 12:27 PM EDT	Special Weather Statement	GYX	Sullivan	48 min
Jul 18, 12:48 PM EDT	Special Weather Statement	GYX	Grafton	42 min
Jul 18, 1:26 PM EDT	Severe Thunderstorm Warning	GYX	Cheshire	34 min
Jul 18, 3:00 PM EDT	Special Weather Statement	GYX	Hillsborough	45 min
Jul 18, 4:27 PM EDT	Special Weather Statement	GYX	Rockingham, Strafford	48 min
Jul 18, 4:33 PM EDT	Severe Thunderstorm Warning	GYX	Hillsborough, Rockingham	42 min
Jul 18, 5:31 PM EDT	Flash Flood Warning	GYX	Rockingham, Strafford	3 hr
Jul 18, 5:32 PM EDT	Special Weather Statement	GYX	Strafford	43 min
Jul 18, 6:12 PM EDT	Special Weather Statement	GYX	Coos	48 min
Jul 18, 6:32 PM EDT	Special Weather Statement	GYX	Sullivan	43 min
Jul 18, 7:13 PM EDT	Special Weather Statement	GYX	Coos, Grafton	47 min
Jul 18, 7:14 PM EDT	Special Weather Statement	GYX	Sullivan	46 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.