Alert archive / Virginia / Frost Advisories in 2020

Frost Advisory 7, NWS Wakefield, VA

October 30, 20205 counties in Virginia; 4 counties in Maryland

NWS Wakefield, VA issued this frost advisory at Oct 30, 2020, 2:04 PM EDT for 5 counties in Virginia; 4 counties in Maryland. It took effect at Oct 31, 2020, 3:00 AM EDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Oct 30, 2020, 2:04 PM EDT (18:04 UTC)
In effect from
Oct 31, 2020, 3:00 AM EDT
Expired
Oct 31, 2020, 9:00 AM EDT
In force
6 hr
Issued by
NWS Wakefield, VA

Counties Dorchester County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Caroline County, VA, Fluvanna County, VA, Goochland County, VA, Hanover County, VA, Louisa County, VA

The radar

The Sterling radar (KLWX), 116 km from the middle of the area, began a volume at 18:06 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

Roanoke, VA (KRNK), launched 12:00Z, 6.1 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, Roanoke, VA at 12:00Z on 2020-10-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Roanoke, VA at 12:00Z on 2020-10-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -102 square meters per square second.1939587897Sfc1 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
1 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
699 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
-102 m²/s²
0-3 km storm-relative helicity
-67 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 29, 11:21 PM EDTSpecial Weather StatementAKQLunenburg, Mecklenburg54 min
Oct 30, 12:16 AM EDTSpecial Weather StatementAKQBrunswick, Dinwiddie, Greensville, Prince George, Sussex, City of Emporia and 1 more59 min
Oct 30, 2:40 AM EDTSpecial Weather StatementAKQSouthampton, City of Franklin65 min
Oct 30, 3:30 AM EDTSpecial Weather StatementAKQCity of Chesapeake, City of Suffolk60 min
Oct 30, 4:29 AM EDTSpecial Weather StatementAKQCity of Virginia Beach46 min
Oct 30, 8:01 AM EDTRiver Flood WarningAKQChesterfield, Henrico, City of Richmond44 hr
Oct 30, 8:01 AM EDTRiver Flood WarningAKQHenrico, City of Richmond44 hr
Oct 30, 10:17 AM EDTRiver Flood WarningAKQAmelia, Cumberland, Prince Edward32 hr
Oct 30, 1:02 PM EDTSmall Craft AdvisoryAKQ43 hr
Oct 30, 2:35 PM EDTCoastal Flood StatementAKQAccomack, Northampton, City of Chesapeake, City of Hampton, City of Virginia Beach10 hr
Oct 30, 3:57 PM EDTGale WatchAKQ24 hr
Oct 30, 2:41 AM EDTAreal Flood AdvisoryAKQDorchester3 hr
Oct 30, 4:42 AM EDTAreal Flood AdvisoryAKQSomerset, Wicomico, Worcester3 hr

Nearby

Frost Advisories in Virginia, 2020Frost Advisories in Maryland, 2020Every 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.