Alert archive / New Jersey / Mesoscale Discussions in 2021
Mesoscale Discussion 1516
The Storm Prediction Center issued this mesoscale discussion at Aug 13, 2021, 6:02 PM EDT for Kent County, New Castle County, Sussex County, Delaware; Wicomico County, Worcester County, Maryland; 5 counties in New Jersey. It was in force for 58 min.
The area
The outline as issued.
The facts
- Issued
- Aug 13, 2021, 6:02 PM EDT (22:02 UTC)
- Expired
- Aug 13, 2021, 7:00 PM EDT
- In force
- 58 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ
The radar
The Dover AFB radar (KDOX), 50 km from the middle of the area, began a volume at 22:04 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
Wallops Is Stn, VA (KWAL), launched 12:00Z, 10.0 hours before the alert went out and 137 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
- 809 J/kg
- Mixed-layer CIN
- -190 J/kg
- Mixed-layer LCL
- 1510 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 55 m²/s²
- 0-3 km storm-relative helicity
- 32 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
596
ACUS11 KWNS 132202
SWOMCD
SPC MCD 132202
NJZ000-MDZ000-DEZ000-132300-
Mesoscale Discussion 1516
NWS Storm Prediction Center Norman OK
0502 PM CDT Fri Aug 13 2021
Areas affected...DE...southern NJ...southeast PA...portions of the
MD Eastern Shore
Concerning...Severe potential...Watch possible
Valid 132202Z - 132300Z
Probability of Watch Issuance...60 percent
SUMMARY...A risk for damaging thunderstorm winds will exist through
the early evening hours. Trends are being monitored for the
possibility of a small Severe Thunderstorm Watch prior to 23z.
DISCUSSION...A broken line of strong/severe thunderstorms producing
scattered reports of wind damage continues to move steadily east
across extreme southeast PA and portions of eastern MD in the
Baltimore vicinity as of 22z. The downstream environment appears
favorable for a continued severe wind risk to the east of Severe
Thunderstorm Watch 436 for at least a few more hours given
moderate/strong MLCAPE, before nocturnal cooling gradually results
in increasing CINH. Latest CAM guidance also suggests a severe risk
continuing into early evening, and trends will continue to be
monitored for the possibility of a small Severe Thunderstorm Watch
prior to 23z.
..Bunting/Goss.. 08/13/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...AKQ...LWX...
LAT...LON 38077518 38247586 39377577 39717561 39767527 39757499
39687474 39537436 39437430 39287429 38587450 38077518SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 12:33 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Carroll, Charles, Frederick, Harford and 5 more | 87 min |
| Aug 13, 1:11 PM EDT | Severe Thunderstorm Watch | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 13 more | 7 hr |
| Aug 13, 4:48 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Cecil, Charles, Harford, Howard and 2 more | 87 min |
| Aug 12, 10:08 PM EDT | Mesoscale Discussion | SPC | Hunterdon, Mercer, Morris, Somerset, Sussex, Warren | 67 min |
Nearby
Mesoscale Discussions in New Jersey, 2021Mesoscale Discussions in Delaware, 2021Mesoscale Discussions in Maryland, 2021Every mesoscale discussion in 2021
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.