Svr Wx & Chase (10/5 - 10/8) -- Update #2

Friday Oct. 5, 10:15 AM: Well the severe threat today will be hampered by the strong capping that is overtaking the northern plains this afternoon. Early thunderstorms and cloudcover are working through central Iowa into areas of eastern MN and Wisconsin this morning. The warm front will be focused over areas of central Minnesota, where the best threat for severe weather does still exist. However, with such a large capping inversion expected over the areas near and to the south of the warm front the only thunderstorms that may get going will be well north of the front. The areas north of the front, although with decent shear values will not have near the instability that will be warranted to maintain some of the stronger severe thunderstorms that seemed possible earlier in the week. If for some reason we are able to break the cap nearer to the warm frontal boundary or just to the south of it, shear values as well as instability could support a substantial threat for large hail and tornadoes. However, with such a large cap expected, that threat is quite minimal thus far and is indicated by the latest SPC day 1 outlook that keeps only minimal probabilities over the area.

Tomorrow's severe weather threat also looks to be limited by the substantially warm air in place ahead of the trough and overall system that will be moving into the plains. A weak low pressure system is likely to form during the day tomorrow, with a cold front drapped to the south through areas of the western high plains. Ahead of this cold front will see warm temperatures not only at the mid-levels, but even higher at 500mb that will weaken even the instability factor for severe thunderstorms. Without substantial instability, expect the cap to hold in the warm sector for the day tomorrow. However, with the trough digging past the Rockies it will have the potential to ignite thunderstorms along it. These thunderstorms will mainly exist behind the cold front however, meaning the best threat seems to be a large hail risk with elevated storms.

Sunday's threat also seems to be on the downfall with the models deciding to disagree with eachother in the strength and position of the trough. Despite the disagreemnt there, the agreement between them does indicate that the day will be a likely mess of convection all over the plains states. A new low pressure system likely to form over some portion of KS/NE during the morning, leading to a nearly stationary boundary over the northern plains states and a cold front, possible dryline to the south over KS/OK and into the Texas Panhandle. Thunderstorms likely to be ongoing around the area of low pressure and along the stationary boundary in the northern plains. Some indications pose that thunderstorms will exist ahead of the front in the central/southern plains as well during the afternoon hours. All of this convection is likely to lead to less instability and overall less threat for severe weather over the plains states. SPC concurs with these, as they have only introduced minimal probabilities for the day over the central/southern plains. All in all it doesn't look like this weekend will be as good as an event as previous indications were pointing towards...