Alert archive / New Hampshire / Flood Watches in 2023

Flood Watch 21, NWS Gray, ME

September 12, 2023Cheshire County, Hillsborough County, Rockingham County, New Hampshire

NWS Gray, ME issued this flood watch at Sep 12, 2023, 3:11 PM EDT for Cheshire County, Hillsborough County, Rockingham County, New Hampshire. It took effect at Sep 13, 2023, 11:00 AM EDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Sep 12, 2023, 3:11 PM EDT (19:11 UTC)
In effect from
Sep 13, 2023, 11:00 AM EDT
Expired
Sep 13, 2023, 6:36 PM EDT
In force
8 hr
Issued by
NWS Gray, ME
Flood severity
None

Counties Cheshire County, NH, Hillsborough County, NH, Rockingham County, NH

The radar

The Boston radar (KBOX), 118 km from the middle of the area, began a volume at 19:12 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, 7.2 hours before the alert went out and 250 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 2023-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 24 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2023-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
24 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
632 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 9:50 PM EDTAreal Flood AdvisoryGYXAndroscoggin, Cumberland, Sagadahoc115 min
Sep 11, 9:54 PM EDTAreal Flood AdvisoryGYXAndroscoggin111 min
Sep 11, 10:37 PM EDTAreal Flood AdvisoryGYXKennebec113 min
Sep 11, 9:22 PM EDTAreal Flood WarningGYXHillsborough, Rockingham3 hr

Nearby

Flood Watches in New Hampshire, 2023Every flood watch 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.