Alert archive / Virginia / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 416

July 25, 20165 states

The Storm Prediction Center issued this severe thunderstorm watch at Jul 25, 2016, 3:30 PM EDT for 5 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 25, 2016, 3:30 PM EDT (19:30 UTC)
Expired
Jul 25, 2016, 9:13 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 57 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Washington County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ, Salem County, NJ, Arlington County, VA, City of Alexandria, 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 Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Loudoun County, VA, Madison County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV

The radar

The Sterling radar (KLWX), 21 km from the middle of the area, began a volume at 19:33 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 25, 3:31 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick44 min
Jul 25, 3:33 PM EDTSevere Thunderstorm WarningLWXPage, Shenandoah, Warren42 min
Jul 25, 3:47 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington43 min
Jul 25, 4:04 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick, Washington39 min
Jul 25, 4:28 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick47 min
Jul 25, 4:42 PM EDTSevere Thunderstorm WarningLWXClarke, Fauquier, Frederick, Loudoun, Prince William48 min
Jul 25, 5:16 PM EDTSevere Thunderstorm WarningLWXMontgomery44 min
Jul 25, 5:44 PM EDTSevere Thunderstorm WarningLWXCharles, Montgomery, Prince George's18 min
Jul 25, 7:58 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean44 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, 7.5 hours before the alert went out and 15 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 2016-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 494 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 2016-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.1939Sfc1 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
494 J/kg
Mixed-layer CIN
-150 J/kg
Mixed-layer LCL
1400 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
56 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
Jul 25, 3:05 PM EDTMesoscale DiscussionSPCKent, Sussex115 min
Jul 25, 5:02 PM EDTMesoscale DiscussionSPCKent, New Castle, Sussex88 min
Jul 25, 7:06 PM EDTMesoscale DiscussionSPCKent, Sussex84 min
Jul 25, 12:41 PM EDTMesoscale DiscussionSPCAllegany, Carroll, Frederick, Garrett, Washington64 min
Jul 25, 12:43 PM EDTSevere Thunderstorm WatchSPCBergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more7 hr
Jul 25, 3:03 PM EDTMesoscale DiscussionSPCBergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more57 min
Jul 25, 4:52 PM EDTMesoscale DiscussionSPCBergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more83 min

Nearby

Severe Thunderstorm Watches in Virginia, 2016Severe Thunderstorm Watches in Maryland, 2016Severe Thunderstorm Watches in West Virginia, 2016Every severe thunderstorm watch 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.