Alert archive / Virginia / Tornado Watches in 2019

Tornado Watch 90

April 19, 201913 counties in Maryland; 34 counties in Virginia; 6 counties in West Virginia

The Storm Prediction Center issued this tornado watch at Apr 19, 2019, 12:48 PM EDT for 13 counties in Maryland; 34 counties in Virginia; 6 counties in West Virginia. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Apr 19, 2019, 12:48 PM EDT (16:48 UTC)
Expired
Apr 19, 2019, 9:50 PM EDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 53 counties

Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Washington County, MD, Albemarle County, VA, Arlington County, VA, Augusta County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Morgan County, WV, Pendleton County, WV

The radar

The Sterling radar (KLWX), 20 km from the middle of the area, began a volume at 16:48 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 19, 1:09 PM EDTSevere Thunderstorm WarningLWXCulpeper, Fauquier, Spotsylvania, Stafford36 min
Apr 19, 3:09 PM EDTSevere Thunderstorm WarningLWXHighland36 min
Apr 19, 4:36 PM EDTSevere Thunderstorm WarningLWXGrant, Hardy39 min
Apr 19, 4:52 PM EDTSevere Thunderstorm WarningLWXRockingham, Shenandoah53 min
Apr 19, 5:07 PM EDTSevere Thunderstorm WarningLWXGrant, Hampshire, Hardy, Mineral53 min
Apr 19, 5:10 PM EDTSevere Thunderstorm WarningLWXAlbemarle, Nelson50 min
Apr 19, 6:15 PM EDTTornado WarningLWXAllegany, Washington30 min
Apr 19, 7:10 PM EDTSevere Thunderstorm WarningLWXCulpeper, Orange, Spotsylvania50 min
Apr 19, 8:05 PM EDTSevere Thunderstorm WarningLWXSpotsylvania, Stafford, City of Fredericksburg40 min
Apr 19, 8:06 PM EDTTornado WarningLWXFrederick, Washington24 min
Apr 19, 8:21 PM EDTSevere Thunderstorm WarningLWXCulpeper, Fauquier, Orange, Prince William, Spotsylvania, Stafford and 3 more39 min
Apr 19, 8:28 PM EDTTornado WarningLWXWashington7 min
Apr 19, 8:34 PM EDTSevere Thunderstorm WarningLWXCalvert, Saint Mary's28 min
Apr 19, 8:41 PM EDTSevere Thunderstorm WarningLWXFrederick, Montgomery34 min
Apr 19, 8:53 PM EDTTornado WarningLWXFairfax, Loudoun22 min
Apr 19, 9:17 PM EDTTornado WarningLWXMontgomery15 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.8 hours before the alert went out and 18 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 2019-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 2019-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 209 square meters per square second.19395878Sfc1 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
7 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
781 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
209 m²/s²
0-3 km storm-relative helicity
191 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 12:08 PM EDTMesoscale DiscussionSPCHoward, Montgomery, City of Baltimore2 hr
Apr 19, 1:17 PM EDTTornado WatchSPCDorchester, Somerset, Wicomico, Worcester11 hr
Apr 19, 3:18 PM EDTMesoscale DiscussionSPCSomerset87 min
Apr 19, 4:32 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Charles, Frederick, Howard, Kent and 3 more58 min
Apr 19, 6:21 PM EDTMesoscale DiscussionSPCCharles, Frederick, Montgomery, Prince George's84 min
Apr 19, 10:06 AM EDTMesoscale DiscussionSPCFloyd, Franklin, Henry, Patrick, Pittsylvania, City of Danville and 2 more84 min
Apr 19, 10:31 AM EDTTornado WatchSPCAlleghany, Amherst, Appomattox, Bath, Bedford, Bland and 29 more9 hr
Apr 19, 12:29 PM EDTMesoscale DiscussionSPCBrunswick, Caroline, Charles City, Chesterfield, Dinwiddie, Greensville and 19 more2 hr
Apr 19, 1:40 PM EDTMesoscale DiscussionSPCAmherst, Appomattox, Bedford, Botetourt, Buckingham, Campbell and 18 more2 hr
Apr 19, 4:35 PM EDTMesoscale DiscussionSPCAppomattox, Brunswick, Campbell, Charlotte, Dinwiddie, Greensville and 9 more55 min

Nearby

Tornado Watches in Virginia, 2019Tornado Watches in Maryland, 2019Tornado Watches in West Virginia, 2019Every tornado watch in 2019

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.