Alert archive / New Hampshire / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 104

April 17, 2002Cumberland County, Oxford County, York County, Maine; 9 counties in New Hampshire; 7 counties in Vermont

The Storm Prediction Center issued this severe thunderstorm watch at Apr 17, 2002, 2:00 PM EDT for Cumberland County, Oxford County, York County, Maine; 9 counties in New Hampshire; 7 counties in Vermont. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 17, 2002, 2:00 PM EDT (18:00 UTC)
Expired
Apr 17, 2002, 7:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Cumberland County, ME, Oxford County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH, Caledonia County, VT, Essex County, VT, Franklin County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Washington County, VT

The radar

The Portland,ME radar (KGYX), 81 km from the middle of the area, began a volume at 18:02 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.

Warnings issued inside it

1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 17, 2:16 PM EDTSevere Thunderstorm WarningGYXOxford59 min

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 6.0 hours before the alert went out and 259 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 12:00Z on 2002-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 799 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, Albany, NY at 12:00Z on 2002-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.193958Sfc1 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
799 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
1313 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

Nearby

Severe Thunderstorm Watches in New Hampshire, 2002Severe Thunderstorm Watches in Vermont, 2002Severe Thunderstorm Watches in Maine, 2002Every severe thunderstorm watch in 2002

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.