Alert archive / Maryland / Frost Advisories in 2010

Frost Advisory 13, NWS Baltimore/Washington

October 31, 2010Clarke County, Fairfax County, City of Fairfax, Virginia; 4 counties in Maryland; Jefferson County, West Virginia

NWS Baltimore/Washington issued this frost advisory at Oct 31, 2010, 1:49 PM EDT for Clarke County, Fairfax County, City of Fairfax, Virginia; 4 counties in Maryland; Jefferson County, West Virginia. It took effect at Nov 1, 2010, 4:00 AM EDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Oct 31, 2010, 1:49 PM EDT (17:49 UTC)
In effect from
Nov 1, 2010, 4:00 AM EDT
Expired
Nov 1, 2010, 9:00 AM EDT
In force
5 hr
Issued by
NWS Baltimore/Washington

Counties Baltimore County, MD, Carroll County, MD, Frederick County, MD, Washington County, MD, City of Fairfax, VA, Clarke County, VA, Fairfax County, VA, Jefferson County, WV

The radar

The Sterling radar (KLWX), 34 km from the middle of the area, began a volume at 17:49 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.8 hours before the alert went out and 230 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, Wallops Is Stn, VA at 12:00Z on 2010-10-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Wallops Is Stn, VA at 12:00Z on 2010-10-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.1939587897117Sfc1 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
2291 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
267 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 31, 4:04 AM EDTFreeze WatchLWXClarke10 hr
Oct 31, 4:22 AM EDTSmall Craft AdvisoryLWX14 hr
Oct 31, 5:57 PM EDTSmall Craft AdvisoryLWX12 hr
Oct 31, 6:10 PM EDTFreeze WarningLWXClarke15 hr

Nearby

Frost Advisories in Maryland, 2010Frost Advisories in Virginia, 2010Frost Advisories in West Virginia, 2010Every frost advisory in 2010

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.