Alert archive / Virginia / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 33, NWS Baltimore/Washington

May 16, 2015Fairfax County, Loudoun County, Virginia; Montgomery County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at May 16, 2015, 5:02 PM EDT for Fairfax County, Loudoun County, Virginia; Montgomery County, Maryland. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 16, 2015, 5:02 PM EDT (21:02 UTC)
Expired
May 16, 2015, 5:45 PM EDT
In force
43 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon

Counties Montgomery County, MD, Fairfax County, VA, Loudoun County, VA

The radar

The Sterling radar (KLWX), 11 km from the middle of the area, began a volume at 21:11 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.0 hours before the alert went out and 8 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, Washington/Dulle, VA at 12:00Z on 2015-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 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, Washington/Dulle, VA at 12:00Z on 2015-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 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
20 J/kg
Mixed-layer CIN
-210 J/kg
Mixed-layer LCL
1233 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
95 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
May 16, 3:25 PM EDTSevere Thunderstorm WarningLWXGreene, Madison50 min
May 16, 4:09 PM EDTSevere Thunderstorm WarningLWXClarke, Frederick, Loudoun, City of Winchester36 min
May 16, 4:14 PM EDTSevere Thunderstorm WarningLWXLoudoun31 min
May 16, 4:19 PM EDTSevere Thunderstorm WarningLWXClarke, Fauquier, Frederick, Rappahannock, Warren28 min
May 16, 4:26 PM EDTSpecial Marine WarningLWX94 min
May 16, 4:31 PM EDTSevere Thunderstorm WarningLWXClarke, Fauquier, Loudoun29 min
May 16, 4:50 PM EDTSpecial Marine WarningLWX115 min
May 16, 5:35 PM EDTSpecial Marine WarningLWX115 min
May 16, 5:48 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax27 min
May 16, 6:16 PM EDTSpecial Marine WarningLWX119 min
May 16, 6:33 PM EDTSpecial Marine WarningLWX87 min
May 16, 6:43 PM EDTSpecial Marine WarningLWX2 hr
May 16, 4:08 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington36 min
May 16, 5:39 PM EDTSevere Thunderstorm WarningLWXCarroll, Howard, Montgomery28 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2015Severe Thunderstorm Warnings in Maryland, 2015Every severe thunderstorm warning in 2015

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.