Mark Farnik
EF5
Note- I had this thread previously listed for Wednesday 6/25, but then realized I was off by a day. Lol. So I fixed it.
With a potentially significant severe event possible on Thursday in the Northern Plains, I thought now would be a good time to start a thread.
A strong shortwave trough will be crossing the Northern Rockies and ejecting out over the Northern Plains on Thursday afternoon/evening. Strengthening mid-level westerlies will result in steep height falls downstream of the shortwave trough. In response, lee side cyclogenesis will take place across eastern WY/northwestern NE/southwestern SD and the resulting surface low will continue to deepen through the afternoon and evening hours. A warm front will extend to the E/SE across far northern NE/southern SD initially and will lift north with time. The large scale forcing will hold off until later in the day, so initiation should be in the 3 p.m. to 6 p.m. time frame.
The 12z WRF run depicts the 60 degree dewpoint isotherm extending as far west as Rapid City, SD, mid to upper 60's across all of northern NE/central SD and a tongue of low 70's poking into northeastern NE and eastern SD at 00z Thursday. With surface temperature's progged in the mid 80's the T/d spreads will be acceptable. The WRF also depicts a bullseye of helicity on the order of 300-400 m2/s2 over eastern SD at 00z. Shear will be ample, with due southerly 25 knot 850 winds veering to 50 knot west/northwesterly winds at 500 mb. With the combination of the deep moisture, strong shear, a deeping surface low and a warm front lifting northward across the area, a significant severe weather outbreak is certainly possible, with tornadic supercells a distinct possibility.
Throwing a dart at a map, while keeping in mind a certain late June outbreak back in 2004, my preliminary target would be Mitchell, SD.
With a potentially significant severe event possible on Thursday in the Northern Plains, I thought now would be a good time to start a thread.
A strong shortwave trough will be crossing the Northern Rockies and ejecting out over the Northern Plains on Thursday afternoon/evening. Strengthening mid-level westerlies will result in steep height falls downstream of the shortwave trough. In response, lee side cyclogenesis will take place across eastern WY/northwestern NE/southwestern SD and the resulting surface low will continue to deepen through the afternoon and evening hours. A warm front will extend to the E/SE across far northern NE/southern SD initially and will lift north with time. The large scale forcing will hold off until later in the day, so initiation should be in the 3 p.m. to 6 p.m. time frame.
The 12z WRF run depicts the 60 degree dewpoint isotherm extending as far west as Rapid City, SD, mid to upper 60's across all of northern NE/central SD and a tongue of low 70's poking into northeastern NE and eastern SD at 00z Thursday. With surface temperature's progged in the mid 80's the T/d spreads will be acceptable. The WRF also depicts a bullseye of helicity on the order of 300-400 m2/s2 over eastern SD at 00z. Shear will be ample, with due southerly 25 knot 850 winds veering to 50 knot west/northwesterly winds at 500 mb. With the combination of the deep moisture, strong shear, a deeping surface low and a warm front lifting northward across the area, a significant severe weather outbreak is certainly possible, with tornadic supercells a distinct possibility.
Throwing a dart at a map, while keeping in mind a certain late June outbreak back in 2004, my preliminary target would be Mitchell, SD.
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