Alert archive / Virginia / Mesoscale Discussions in 2016
Mesoscale Discussion 1004
The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2016, 3:34 PM EDT for 7 counties in Maryland; 42 counties in Virginia. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Jun 21, 2016, 3:34 PM EDT (19:34 UTC)
- Expired
- Jun 21, 2016, 5:00 PM EDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
All 49 counties
Calvert County, MD, Charles County, MD, Dorchester County, MD, Prince George's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Albemarle County, VA, Buckingham County, VA, Caroline County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Richmond, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Henrico County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Madison County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA
The radar
The Sterling radar (KLWX), 63 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.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 7.6 hours before the alert went out and 61 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.
- 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
The text
As transmitted.
597
ACUS11 KWNS 211934
SWOMCD
SPC MCD 211934
MDZ000-VAZ000-DCZ000-212100-
MESOSCALE DISCUSSION 1004
NWS STORM PREDICTION CENTER NORMAN OK
0234 PM CDT TUE JUN 21 2016
AREAS AFFECTED...VIRGINIA...SRN MARYLAND...DELAWARE
CONCERNING...SEVERE THUNDERSTORM WATCH 278...
VALID 211934Z - 212100Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 278
CONTINUES.
SUMMARY...RISK FOR SEVERE STORMS CONTINUES THROUGH 21-23Z...MOSTLY
TO THE SOUTH OF THE WASHINGTON D.C. AREA.
DISCUSSION...PORTION OF EVOLVING THUNDERSTORM CLUSTER WITH BOW ECHO
REFLECTIVITY SIGNATURE APPEARS LIKELY TO CONTINUE SOUTHEASTWARD
PROPAGATION... SOUTH THROUGH SOUTHEAST OF DOVER...AND OFF THE
DELAWARE COAST WITHIN THE NEXT HOUR OR SO. OUTFLOW ASSOCIATED WITH
THIS SYSTEM HAS ADVANCED INTO SOUTHERN PORTIONS OF THE GREATER
WASHINGTON D.C. METRO AREA...AND COULD STILL PROVIDE A FOCUS FOR
ANOTHER EVOLVING CLUSTER OF STORMS...BENEATH SEASONABLY STRONG WEST
NORTHWEST MID-LEVEL FLOW ACROSS SOUTHERN MARYLAND AND THE SOUTHERN
DELMARVA PENINSULA THROUGH 21-23Z. OTHERWISE...FARTHER TO THE
SOUTHWEST AND SOUTH...DISCRETE STORMS ARE IN THE PROCESS OF
PROPAGATING EAST SOUTHEAST OF THE BLUE RIDGE MOUNTAINS. AT LEAST
ONE OR TWO OF THESE MAY INTENSIFY FURTHER...IN THE PRESENCE OF
MODERATE LARGE BOUNDARY LAYER CAPE...AND COULD STILL POSE A RISK FOR
SEVERE WIND/HAIL ACROSS AND EAST OF THE INTERSTATE 95 CORRIDOR...AS
FAR SOUTH AS THE RICHMOND AREA.
..KERR.. 06/21/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PHI...AKQ...LWX...RNK...
LAT...LON 38277898 38867838 39177793 38897734 38857703 38787620
38187553 37307614 37547857 38277898SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 12:00 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 10 more | 90 min |
| Jun 21, 1:06 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 17 more | 9 hr |
| Jun 21, 2:01 PM EDT | Severe Thunderstorm Watch | SPC | Garrett | 8 hr |
| Jun 21, 6:30 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 16 more | 90 min |
| Jun 21, 1:08 PM EDT | Mesoscale Discussion | SPC | Buchanan | 97 min |
| Jun 21, 4:26 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Tazewell, Wise and 1 more | 94 min |
Nearby
Mesoscale Discussions in Virginia, 2016Mesoscale Discussions in Maryland, 2016Every mesoscale discussion 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.