Alert archive / Virginia / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 129, NWS Baltimore/Washington

June 21, 20164 counties in Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Jun 21, 2016, 7:04 PM EDT for 4 counties in Virginia. It was in force for 14 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: Jun 21, 2016, 7:04 PM EDT (23:04 UTC)
Expired: Jun 21, 2016, 7:18 PM EDT
In force: 14 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Arlington County, VA, City of Alexandria, VA, City of Falls Church, VA, Fairfax County, VA

The radar

The Sterling radar (KLWX), 32 km from the middle of the area, began a volume at 23:07 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 21, 1:06 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.1 hours before the alert went out and 24 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: 719 J/kg
Mixed-layer CIN: -132 J/kg
Mixed-layer LCL: 1478 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 143 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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 Jun 21, 3:08 PM EDT, 3 hours 56 minutes earlier.

Area forecast discussion, Jun 21, 3:08 PM EDT, 3 hours 56 minutes before

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
308 PM EDT TUE JUN 21 2016

.SYNOPSIS...
A cold front will cross the region this evening. High pressure
will briefly build in from Canada on Wednesday. A warm front will
lift north across the region Wednesday night. Another cold front
will cross the region later Thursday and Thursday night. High
pressure will build back across the area for the weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
Very active afternoon with plenty of showers and thunderstorms.
Severe Thunderstorm Watch is in effect until 9PM but will probably
be able to start shaving off portions of it as it becomes more
clear where the first line has stabilized the atmosphere.

Patchy fog possible overnight. Otherwise...high pressure from
Canada will usher in drier air for the region on Wednesday.
Temperatures will drop a bit but northwesterly downslope flow
likely to prevent a big drop.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Front that moves through as a cold front tonight will push back
north as a warm front on Wednesday night with rain and perhaps
embedded thunder moving back across the region. Very warm and
humid air mass moves in behind warm front for Thursday and we will
have another potential round of severe weather later Thursday into
Thursday evening. As front drops back south on Thursday night the
showers and thunderstorms will move southeast away from the area.

An upper trough of low pressure will swing across the region
Friday. There is a chance for a lingering shower or thunderstorm,
mainly across the west and south.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pressure will build into the region Friday night through
Sunday. Drier and cooler air will follow throughout the weekend.

This same area of high pressure will move offshore and closer
to southern New England Sunday night and Monday. A warm and more
humid return flow will evolve Sunday night through Tuesday. This
will help in fueling showers and thunderstorms each period. A few
thunderstorms could contain gusty winds.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Brief IFR with severe thunderstorms across the region at present.
Hail and damaging winds main threat. This threat will rapidly
diminish this evening as cold front sinks south with VFR later
tonight thru Wednesday. Front moves back in as a warm front with
more rain later Wednesday night into early Thursday. Another round
of severe weather possible later Thursday into Thursday night.

Ifr conditions possible near CHO with any showers or
thunderstorms Friday. Vfr conditions all terminals Friday night.
Winds northeast around 5 knots Friday becoming southeast around 5
knots Friday night.

&&

.MARINE...
Marginal SCA continues at present. Also have damaging
thunderstorms with wind and hail moving across the waters thru
early this evening. Conditions improve later tonight and continue
dry thru Wednesday, though winds may be near SCA limits on
Wednesday. Warm front moves in with more rain later Wednesday
night then SCA looking likely ahead of next cold front on Thursday
into Thursday night, along with another round of t-storms.

No marine hazards expected Friday and Friday night.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     ANZ530>543.

&&

SYNOPSIS...RCM
NEAR TERM...RCM
SHORT TERM...RCM
LONG TERM...KLW
AVIATION...RCM/KLW
MARINE...RCM/KLW

Hazardous weather outlook, Jun 21, 6:42 PM EDT, 22 minutes before

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In the hours before

Local storm report, Jun 21, 5:59 PM EDT, 1 hour 5 minutes before

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Local storm report, Jun 21, 6:02 PM EDT, 1 hour 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
602 PM EDT TUE JUN 21 2016

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

0538 PM     HAIL             BRUNSWICK               39.32N  77.62W
06/21/2016  E1.00 INCH       FREDERICK          MD   TRAINED SPOTTER

&&

EVENT NUMBER LWX1604190

LEE

Local storm report, Jun 21, 6:10 PM EDT, 54 minutes before

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Local storm report, Jun 21, 6:41 PM EDT, 23 minutes before

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Local storm report, Jun 21, 7:02 PM EDT, 2 minutes before

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Local storm report, Jun 21, 7:03 PM EDT, 1 minute 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
Jun 21, 12:50 PM EDT	Severe Thunderstorm Warning	LWX	Frederick	40 min
Jun 21, 1:11 PM EDT	Special Marine Warning	LWX		2 hr
Jun 21, 1:12 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Fauquier, Loudoun, Prince William	48 min
Jun 21, 1:23 PM EDT	Severe Thunderstorm Warning	LWX	Frederick	52 min
Jun 21, 1:51 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	39 min
Jun 21, 2:02 PM EDT	Severe Thunderstorm Warning	LWX	Madison, Page, Shenandoah, Warren	43 min
Jun 21, 2:05 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Fauquier, Frederick, Loudoun, City of Winchester	20 min
Jun 21, 2:16 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Augusta, Greene, Rockingham, City of Harrisonburg	44 min
Jun 21, 2:20 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, City of Alexandria, City of Falls Church	36 min
Jun 21, 2:24 PM EDT	Special Marine Warning	LWX		2 hr
Jun 21, 2:32 PM EDT	Special Marine Warning	LWX		43 min
Jun 21, 2:35 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Madison, Rappahannock	40 min
Jun 21, 2:54 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Fauquier, Loudoun, Prince William	34 min
Jun 21, 2:58 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, City of Charlottesville	47 min
Jun 21, 3:02 PM EDT	Severe Thunderstorm Warning	LWX	Fauquier	15 min
Jun 21, 3:06 PM EDT	Special Marine Warning	LWX		84 min
Jun 21, 3:17 PM EDT	Severe Thunderstorm Warning	LWX	Fauquier, Prince William	13 min
Jun 21, 3:27 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Loudoun, Prince William, City of Alexandria, City of Fairfax, City of Manassas and 1 more	48 min
Jun 21, 3:31 PM EDT	Special Marine Warning	LWX		119 min
Jun 21, 3:32 PM EDT	Special Marine Warning	LWX		118 min
Jun 21, 3:40 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, City of Charlottesville	20 min
Jun 21, 3:51 PM EDT	Severe Thunderstorm Warning	LWX	Page, Rockingham, Shenandoah	39 min
Jun 21, 4:15 PM EDT	Special Marine Warning	LWX		2 hr
Jun 21, 4:23 PM EDT	Severe Thunderstorm Warning	LWX	Madison, Page, Rappahannock, Shenandoah	28 min
Jun 21, 4:31 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Loudoun, City of Winchester	29 min
Jun 21, 4:43 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	36 min
Jun 21, 4:49 PM EDT	Areal Flood Warning	LWX	Madison, Page, Rappahannock, Rockingham, Shenandoah	6 hr
Jun 21, 4:50 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Madison, Rappahannock	26 min
Jun 21, 4:53 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Fauquier, Loudoun, Prince William	52 min
Jun 21, 4:57 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	48 min
Jun 21, 5:10 PM EDT	Special Marine Warning	LWX		95 min
Jun 21, 5:31 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	44 min
Jun 21, 5:32 PM EDT	Flash Flood Warning	LWX	Fairfax, Fauquier, Loudoun, Prince William, City of Fairfax	3 hr
Jun 21, 5:44 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick	46 min
Jun 21, 5:51 PM EDT	Flash Flood Warning	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	3 hr
Jun 21, 6:11 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	49 min
Jun 21, 6:15 PM EDT	Special Marine Warning	LWX		2 hr
Jun 21, 6:36 PM EDT	Special Marine Warning	LWX		84 min
Jun 21, 12:01 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Washington	44 min
Jun 21, 12:39 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick, Washington	36 min
Jun 21, 12:47 PM EDT	Severe Thunderstorm Warning	LWX	Washington	27 min
Jun 21, 1:01 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Carroll, Frederick, Howard, Montgomery, Washington	31 min
Jun 21, 1:19 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Carroll, Frederick, Howard, Montgomery and 2 more	56 min
Jun 21, 1:34 PM EDT	Tornado Warning	LWX	Baltimore, Howard	26 min
Jun 21, 2:05 PM EDT	Flash Flood Warning	LWX	Anne Arundel, Baltimore, Harford, Howard, City of Baltimore	4 hr
Jun 21, 2:08 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel	52 min
Jun 21, 2:13 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Calvert, Prince George's	32 min
Jun 21, 2:28 PM EDT	Flash Flood Warning	LWX	Howard, Montgomery	3 hr
Jun 21, 2:53 PM EDT	Areal Flood Warning	LWX	Anne Arundel, Howard, Prince George's	6 hr
Jun 21, 3:11 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Calvert, Montgomery, Prince George's	49 min
Jun 21, 3:29 PM EDT	Severe Thunderstorm Warning	LWX	Calvert, Charles, Prince George's, Saint Mary's	22 min
Jun 21, 3:45 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's	60 min
Jun 21, 5:17 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Carroll, Frederick, Howard, Montgomery	43 min
Jun 21, 6:06 PM EDT	Flash Flood Warning	LWX	Baltimore, City of Baltimore	3 hr
Jun 21, 6:31 PM EDT	Severe Thunderstorm Warning	LWX	Washington	44 min
Jun 21, 7:09 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Washington	51 min
Jun 21, 7:31 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick, Howard, Montgomery	44 min
Jun 21, 7:51 PM EDT	Severe Thunderstorm Warning	LWX	Washington	11 min
Jun 21, 4:17 PM EDT	Severe Thunderstorm Warning	LWX	Grant, Hardy, Pendleton	28 min
Jun 21, 4:58 PM EDT	Severe Thunderstorm Warning	LWX	Grant	15 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2016 Every severe thunderstorm warning in 2016

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.