Alert archive / Virginia / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 25, NWS Baltimore/Washington

May 6, 20154 counties in Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at May 6, 2015, 7:39 PM EDT for 4 counties in Virginia. It was in force for 36 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 6, 2015, 7:39 PM EDT (23:39 UTC)
Expired: May 6, 2015, 8:15 PM EDT
In force: 36 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Culpeper County, VA, Madison County, VA, Orange County, VA, Spotsylvania County, VA

The radar

The Sterling radar (KLWX), 83 km from the middle of the area, began a volume at 23:42 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, 11.7 hours before the alert went out and 85 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: 58 J/kg
Mixed-layer CIN: -187 J/kg
Mixed-layer LCL: 1430 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 43 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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this severe thunderstorm warning went out at May 6, 5:09 PM EDT, 2 hours 30 minutes earlier.

Area forecast discussion, May 6, 5:09 PM EDT, 2 hours 30 minutes before

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Hazardous weather outlook, May 6, 4:45 PM EDT, 2 hours 54 minutes before

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In the hours before

Local storm report, May 6, 3:42 PM EDT, 3 hours 57 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
342 PM EDT WED MAY 06 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0340 PM     HAIL             1 SE RESTON             38.94N  77.33W
05/06/2015  M0.88 INCH       FAIRFAX            VA   TRAINED SPOTTER

            DIME TO NICKEL SIZE

&&

EVENT NUMBER LWX1500111

ADS

Local storm report, May 6, 3:44 PM EDT, 3 hours 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
344 PM EDT WED MAY 06 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0344 PM     HAIL             1 SSE CENTREVILLE       38.83N  77.43W
05/06/2015  M0.75 INCH       FAIRFAX            VA   TRAINED SPOTTER

&&

EVENT NUMBER LWX1500112

ADS

Local storm report, May 6, 3:50 PM EDT, 3 hours 49 minutes before

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Local storm report, May 6, 3:59 PM EDT, 3 hours 40 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
359 PM EDT WED MAY 06 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0338 PM     HAIL             2 S HERNDON             38.94N  77.39W
05/06/2015  E1.00 INCH       FAIRFAX            VA   PUBLIC

&&

EVENT NUMBER LWX1500114

ADS

Local storm report, May 6, 4:06 PM EDT, 3 hours 33 minutes before

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Local storm report, May 6, 4:58 PM EDT, 2 hours 41 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
May 6, 1:52 AM EDT	Dense Fog Advisory	LWX	Culpeper, Fauquier, Greene, Madison, Orange, Page and 6 more	6 hr
May 6, 2:45 PM EDT	Severe Thunderstorm Warning	LWX	Frederick	30 min
May 6, 3:19 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, City of Fairfax	41 min
May 6, 3:32 PM EDT	Severe Thunderstorm Warning	LWX	Frederick	28 min
May 6, 3:56 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Shenandoah, City of Winchester	23 min
May 6, 4:04 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax	23 min
May 6, 4:12 PM EDT	Severe Thunderstorm Warning	LWX	Fauquier, Prince William	22 min
May 6, 4:41 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Fauquier, Frederick, Loudoun, Warren	34 min
May 6, 4:48 PM EDT	Severe Thunderstorm Warning	LWX	Fauquier	27 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2015 Every 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.