PDS Tornado Watch 333 in effect until 9PM EDT June 23 2020
Hazards:
Numerous long-track strong to violent tornadoes expected
Numerous significant wind gusts to 115 mph likely
Widespread large hail with scattered giant hail events to 5" in diameter likely
Discussion:
A well-developed and intense MCS/derecho continues to move through much of West Virginia AOA 65kts. The environment within the watch area is characterized by extreme instability (MLCAPE 7000-8000+ J/kg), impressive shear (EBWD 70-90 kts), high moisture content (Pwats of 2-2.25"+) and strong DCAPE (1200-1600+ J/kg). As the MCS moves into the mountains additional supercells are expected to rapidly develop by 19-20z along the foothills/Blue ridge ahead of the main line and move east through the DC and Baltimore metropolitan areas. With the extreme low-level shear also in place (effective SRH of 500-900 m2/s2) these cells will have a high risk of producing long-track and potenially violent tornadoes as well as giant, life-threatening hail. The greatest wind threat over this region will come with the main line of storms between 20-23z with high-end severe winds (possibly in excess of 115 mph). Storms will move out of the watch area by 00z.
Forecaster: George BM
Look at the 20z Mesoscale Analysis! Unreal.
And just look at that sounding from the 20z special balloon launch!