Alert archive / Virginia / Frost Advisories in 2020

Frost Advisory 1, NWS Blacksburg, VA

April 15, 20206 counties in Virginia; 6 counties in North Carolina

NWS Blacksburg, VA issued this frost advisory at Apr 15, 2020, 3:37 AM EDT for 6 counties in Virginia; 6 counties in North Carolina. It took effect at Apr 16, 2020, 2:00 AM EDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Apr 15, 2020, 3:37 AM EDT (07:37 UTC)
In effect from: Apr 16, 2020, 2:00 AM EDT
Expired: Apr 16, 2020, 8:00 AM EDT
In force: 6 hr
Issued by: NWS Blacksburg, VA

Counties Caswell County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Wilkes County, NC, Yadkin County, NC, Charlotte County, VA, City of Danville, VA, City of Martinsville, VA, Halifax County, VA, Henry County, VA, Pittsylvania County, VA

The radar

The Roanoke radar (KFCX), 66 km from the middle of the area, began a volume at 07:37 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.6 hours before the alert went out and 52 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1761 m above ground
0-6 km bulk shear: 94 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 457 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 frost advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Blacksburg, VA wrote its last area forecast discussion before this frost advisory went out at Apr 15, 1:37 AM EDT, 2 hours earlier.

Area forecast discussion, Apr 15, 1:37 AM EDT, 2 hours before

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Hazardous weather outlook, Apr 14, 2:54 PM EDT, 12 hours 43 minutes before

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In the hours before

Special weather statement, Apr 15, 1:14 AM EDT, 2 hours 23 minutes before

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Local storm report, Apr 15, 2:30 AM EDT, 1 hour 7 minutes before

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The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 15, 3:37 AM EDT	Freeze Watch	RNK	Botetourt, Rockbridge, City of Buena Vista, City of Lexington	11 hr
Apr 15, 2:46 PM EDT	Freeze Warning	RNK	Botetourt, Rockbridge, City of Buena Vista, City of Lexington	17 hr

Nearby

Frost Advisories in Virginia, 2020 Frost Advisories in North Carolina, 2020 Every frost advisory in 2020

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.