Mesoscale Discussion 1515

Issued

Aug 13, 2021, 4:48 PM EDT (20:48 UTC)

Expired

Aug 13, 2021, 6:15 PM EDT

In force

87 min

Issued by

the Storm Prediction Center

Concerning

Severe thunderstorm watch 436

Counties Anne Arundel County, MD, Baltimore County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Harford County, MD, Howard County, MD, Prince George's County, MD, Chester County, PA, Arlington County, VA, Caroline County, VA, City of Alexandria, VA, City of Falls Church, VA, City of Fredericksburg, VA, Fairfax County, VA, Goochland County, VA, King George County, VA, Louisa County, VA, Spotsylvania County, VA, Stafford County, VA

The Sterling radar (KLWX), 49 km from the middle of the area, began a volume at 20:50 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.

795 
ACUS11 KWNS 132049
SWOMCD
SPC MCD 132048 
PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-132215-

Mesoscale Discussion 1515
NWS Storm Prediction Center Norman OK
0348 PM CDT Fri Aug 13 2021

Areas affected...central into northern VA...MD...far southeast PA

Concerning...Severe Thunderstorm Watch 436...

Valid 132048Z - 132215Z

The severe weather threat for Severe Thunderstorm Watch 436
continues.

SUMMARY...Severe gusts are possible and perhaps becoming maximized
in coverage over the next 1-2 hours from 30 mi north of Richmond
northward through D.C./BWI and through the upper Chesapeake Bay
vicinity.

DISCUSSION...Radar mosaic shows several strong to severe
thunderstorm clusters from 35 mi north-northwest of Richmond and
northward into southeast PA as of 445pm.  The Warrenton-Fauquier
(KHWY) ASOS recently observed a measured 56-kt gust at 435pm.  This
activity is moving east into the I-95 corridor during the next 1-2
hours.  With surface temperatures in the low-mid 90s with low-mid
70s dewpoints, the stronger water-loaded cores will be capable of
damaging microbursts and gusts in the 50-70 mph range.

..Smith.. 08/13/2021

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

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

LAT...LON   37797812 39257696 40007626 39977554 38207697 37507785
            37797812

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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.