Alert archive / Virginia / Mesoscale Discussions in 2023
Mesoscale Discussion 2113
The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2023, 6:34 PM EDT for 7 states. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Sep 8, 2023, 6:34 PM EDT (22:34 UTC)
- Expired
- Sep 8, 2023, 8:00 PM EDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 674
All 69 counties
Kent County, DE, New Castle County, DE, 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, 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, Camden County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Orange County, NY, Adams County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Stafford County, VA, Warren County, VA, Jefferson County, WV
The radar
The Dover AFB radar (KDOX), 122 km from the middle of the area, began a volume at 22:35 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, 10.6 hours before the alert went out and 161 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
- 374 J/kg
- Mixed-layer CIN
- -194 J/kg
- Mixed-layer LCL
- 1095 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 17 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
The text
As transmitted.
298
ACUS11 KWNS 082234
SWOMCD
SPC MCD 082234
NJZ000-NYZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-090000-
Mesoscale Discussion 2113
NWS Storm Prediction Center Norman OK
0534 PM CDT Fri Sep 08 2023
Areas affected...portions of northern Virginia into
Maryland...Delaware...eastern Pennsylvania...New Jersey...Extreme
Southeast New York
Concerning...Severe Thunderstorm Watch 674...
Valid 082234Z - 090000Z
The severe weather threat for Severe Thunderstorm Watch 674
continues.
SUMMARY...The severe threat continues across Severe Thunderstorm
Watch 674. Damaging winds and large hail may accompany the stronger
storms, especially where the airmass has yet to be overturned by
earlier storms.
DISCUSSION...Pulse cellular and multicellular storms are in progress
amid multiple confluence bands across the Mid Atlantic into the
lower Hudson Valley. Several instances of damaging gusts and severe
hail have been observed with the stronger storms over the past few
hours. However, many of these storms have overturned the airmass
over several locales, tempering storm potency to some degree.
However, a narrow corridor of pristine air resides across central MD
into southeast PA, with surface temperatures near 90 F contributing
to 1500-2000 J/kg MLCAPE. Any storms that can develop or propagate
into this environment may produce damaging gusts and perhaps large
hail into the evening hours.
..Squitieri.. 09/08/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OKX...PHI...BGM...AKQ...CTP...LWX...
LAT...LON 38477870 40017718 41127567 41557471 41437421 40867414
40217448 39377505 38707572 38197675 38477870SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 8, 1:58 PM EDT | Mesoscale Discussion | SPC | Sussex | 92 min |
| Sep 8, 2:46 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle | 119 min |
| Sep 8, 3:11 PM EDT | Severe Thunderstorm Watch | SPC | Kent, New Castle, Sussex | 8 hr |
| Sep 8, 4:52 PM EDT | Mesoscale Discussion | SPC | Bergen, Essex, Hudson, Hunterdon, Mercer, Middlesex and 7 more | 83 min |
| Sep 7, 9:16 PM EDT | Mesoscale Discussion | SPC | Washington | 59 min |
| Sep 8, 3:34 PM EDT | Severe Thunderstorm Watch | SPC | Albany, Columbia, Dutchess, Greene, Rensselaer, Ulster | 7 hr |
| Sep 8, 6:47 PM EDT | Mesoscale Discussion | SPC | Rensselaer | 88 min |
| Sep 8, 5:20 PM EDT | Mesoscale Discussion | SPC | Brunswick, Chesterfield, Dinwiddie, Greensville, Henrico, Isle of Wight and 15 more | 85 min |
Nearby
Mesoscale Discussions in Virginia, 2023Mesoscale Discussions in Maryland, 2023Mesoscale Discussions in Pennsylvania, 2023Every mesoscale discussion in 2023
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.