Mesoscale Discussion 0905 NWS Storm Prediction Center Norman OK 0803 PM CDT Wed Jun 10 2020 Areas affected...The lower Great Lakes/upper Ohio Valley/Allegheny Plateau vicinity Concerning...Severe Thunderstorm Watch 279... Valid 110103Z - 110200Z The severe weather threat for Severe Thunderstorm Watch 279 continues. SUMMARY...Squall line progressing across the region may continue to pose a risk for damaging wind gusts another couple of hours, into 10-11 PM EDT time frame, before tending to weaken. DISCUSSION...The pre-frontal squall line has filled in over the past couple of hours, with a number of embedded bow/lewp radar reflectivity structures. Although activity has been generally maintaining strength, the boundary layer air mass ahead it is beginning to become less unstable with the onset of diurnal cooling. With the primary supporting short wave impulse tending to accelerate north-northeastward through lower Michigan, weakening trends could be fairly rapid as the convection begins to process more stable air. However, until this occurs, stronger convection may continue to pose a risk for potentially damaging wind gusts, and this includes the portion of the line which could impact the Greater Pittsburgh metro area by around 02Z. ..Kerr.. 06/11/2020 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF...CTP...PBZ...RLX...CLE... LAT...LON 42567996 41807901 39787987 38988071 38358225 38858171 39228129 39978062 40908077 41758066 42567996