Alert archive / Vermont / Mesoscale Discussions in 2018

Mesoscale Discussion 356

May 4, 2018Coos County, Grafton County, New Hampshire; 11 counties in New York; 13 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at May 4, 2018, 6:48 PM EDT for Coos County, Grafton County, New Hampshire; 11 counties in New York; 13 counties in Vermont. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
May 4, 2018, 6:48 PM EDT (22:48 UTC)
Expired
May 4, 2018, 8:45 PM EDT
In force
117 min
Issued by
the Storm Prediction Center
All 26 counties

Coos County, NH, Grafton County, NH, Clinton County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Oneida County, NY, Saratoga County, NY, St. Lawrence County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 81 km from the middle of the area, began a volume at 22:50 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 12:00Z, 10.8 hours before the alert went out and 129 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 2018-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2018-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
812 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 4, 2:18 PM EDTMesoscale DiscussionSPCBelknap, Carroll, Cheshire, Coos, Grafton, Merrimack and 1 more87 min
May 4, 5:52 PM EDTMesoscale DiscussionSPCCheshire, Hillsborough83 min
May 4, 6:20 PM EDTSevere Thunderstorm WatchSPCBelknap, Cheshire, Coos, Grafton, Hillsborough, Merrimack and 1 more4 hr
May 4, 7:54 PM EDTMesoscale DiscussionSPCBelknap, Carroll, Coos, Grafton, Strafford3 hr
May 4, 1:04 PM EDTMesoscale DiscussionSPCCattaraugus, Chautauqua, Erie, Genesee, Livingston, Monroe and 1 more86 min
May 4, 2:23 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Cayuga, Chemung, Cortland, Erie and 17 more97 min
May 4, 2:44 PM EDTSevere Thunderstorm WatchSPCAllegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 23 more6 hr
May 4, 3:16 PM EDTTornado WatchSPCClinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 5 more6 hr
May 4, 4:20 PM EDTMesoscale DiscussionSPCAllegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 21 more55 min

Nearby

Mesoscale Discussions in Vermont, 2018Mesoscale Discussions in New York, 2018Mesoscale Discussions in New Hampshire, 2018Every mesoscale discussion in 2018

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.