ZCZC SPCSWOMCD ALL ACUS11 KWNS 050808 SPC MCD 050808 MNZ000-SDZ000-NDZ000-MTZ000-050945- Mesoscale Discussion 1642 NWS Storm Prediction Center Norman OK 0308 AM CDT Mon Aug 05 2019 Areas affected...North Dakota Concerning...Severe Thunderstorm Watch 551... Valid 050808Z - 050945Z The severe weather threat for Severe Thunderstorm Watch 551 continues. SUMMARY...Thunderstorms continue along and ahead of a slowly southward-advancing cold front. Although the environment will continue to support hail and gusty winds, increasing thunderstorm coverage should limit a more widespread severe threat in the near term. DISCUSSION...A midlevel vorticity maximum continues to slowly progress southeast from Canada into North Dakota. Associated with this vorticity maximum, a surface cold front is also making its way slowly southward across the region. Severe thunderstorms developed along and ahead of this front early this evening producing hail and strong winds. With time, increasing cold pools and precipitation shields have merged into a large, west-east oriented mesoscale convective system (MCS). The overall environment will continue to support severe thunderstorms. Mixed-layer CAPE between 500-1500 J/kg, with most-unstable CAPE closer to 3000 J/kg existing just downstream of the MCS, should continue to provide ample buoyancy for ongoing thunderstorms. Additionally, deep-layer shear between 35-50 knots should support updraft/downdraft organization. Hail and gusty thunderstorm winds will be the likely threat with the strongest thunderstorms. The limiting factor for a more widespread severe event will be the combination of increasing surface-based inhibition and the expanding cold pool. NWS 88D radar imagery from Bismarck, North Dakota, indicates the MCS outflow has pushed well downstream of the main MCS by 1-2 counties, limiting this portion of the MCS to ingesting elevated parcels. Farther east, ahead of the main MCS, elevated thunderstorms are developing, which should act to lessen buoyancy and increase surface-based inhibition. With all this written, given sufficient buoyancy, seasonably-strong deep-layer shear, and convergence along the cold front, the threat for hail and gusty winds on an episodic basis should continue for at least another few hours. Later this morning, near the commencement of diurnal heating, an increase in convective intensity may occur as ongoing thunderstorms move into a less convectively contaminated environment. If this occurs, a new downstream watch may be needed later this morning. ..Marsh.. 08/05/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...ABR...BIS...GGW... LAT...LON 47340404 48630404 48650294 48540289 48560227 48800213 48710186 48470183 48470106 48630099 48620044 48520041 48549949 48399949 48389890 48519899 48519833 48209827 48169652 47889648 47769629 47749589 47889562 47499557 47499603 47169608 47149623 46639622 46619630 46049633 46049656 45929662 45979898 46299907 46269992 46639994 46640073 46940097 47260104 47220140 47230174 46980175 46960216 47020221 46970300 47310307 47310307 47340404 NNNN