Mesoscale Discussion 504

Issued

May 3, 2021, 7:16 PM EDT (23:16 UTC)

Expired

May 3, 2021, 7:45 PM EDT

In force

29 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

5%

Counties Baltimore County, MD, Carroll County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Jefferson County, WV

The Sterling radar (KLWX), 60 km from the middle of the area, began a volume at 23:19 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.

129 
ACUS11 KWNS 032316
SWOMCD
SPC MCD 032316 COR
DEZ000-MDZ000-PAZ000-VAZ000-WVZ000-032345-

Mesoscale Discussion 0504
NWS Storm Prediction Center Norman OK
0616 PM CDT Mon May 03 2021

Areas affected...Portions of Maryland...Virginia...and Washington
DC.

Concerning...Severe potential...Watch unlikely 

Valid 032316Z - 032345Z

CORRECTED FOR COUNTY REFERENCE

Probability of Watch Issuance...5 percent

SUMMARY...An isolated risk of damaging winds or a brief tornado will
be possible over the next couple of hours along a diffuse warm
front. A weather watch is unlikely.

DISCUSSION...Recent radar imagery and storm reports showed a small
supeprcell over Federick Co. Maryland had intensified over the last
45 minutes. SPC mesoanalysis indicates this storm is located along a
diffuse surface warm front stretching from eastern Ohio toward the
northern Chesapeake Bay. To the south of the front, surface
temperatures in the mid 70s F and dewpoints in the lower to middle
60s F are support MUCAPE of 800-1200 J/kg. Enhanced mid-level flow
ahead of a shortwave trough across the Carolinas is contributing to
30-40 kt of effective shear as analyzed by local VAD VWPs.
Observational trend suggest that severe weather in the form of
damaging wind gusts and perhaps a tornado will be possible with this
storm as it tracks east along the front over the next 1 to 2 hours.
Given the limited spatial area and expected longevity of any severe
risk as the storm moves into cooler air near the bay, a weather
watch is unlikely.

..Lyons/Thompson.. 05/03/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PHI...CTP...LWX...

LAT...LON   39317762 39257795 39477795 39727755 39677697 39647614
            39477571 39187595 39077645 39197751 39317762

Mesoscale Discussions in Maryland, 2021Mesoscale Discussions in West Virginia, 2021Every mesoscale discussion in 2021

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.