We’re tracking a strong cold front that brings a chance for severe storms later today and blustery weather tonight into Friday. 

The lead southern stream wave is ejecting into the Missouri Valley this morning taking the elevated overnight storms away from the area.  The powerful northern stream trough is moving across the Rockies this morning, located near Wyoming with upper jet streaks winds nearing 80 knots at the base of the trough across the southern Rockies and northern desert southwest.  This system will move into the central plains today and will be located near Minnesota Friday into Saturday.  A surface low pressure area has rapidly developed (lee side cyclogenesis) and is now located across northern Kansas this morning and will transit across the upper Midwest Friday.  A trailing cold front from the low will surge southward this morning and enter northcentral OK and southcentral Kansas by noon.  We anticipate this front nearing the metro between 1pm and 3pm with a narrow line of storms rapidly developing and expanding in maturity as the front pushes quickly into east central and southcentral OK early this evening. 

Convective potential energy around 2000 j/kg combined with adequate low-level shear will present severe thunderstorm chances including hail and wind near and east of the boundary.   Deep layer shear is marginal over the projected time and space, with stronger values slightly removed to the west of the expected development.  Any discrete cells, especially any that may form well ahead of the front, could rotate and have some low-end tornado potential.  The upper flow is mostly parallel to the surface boundary and will keep most threats linear in nature by later in the afternoon, meaning squall-line variety severe as the system moves southeast. 

Normally this front under the current air flow would be a slow mover, but pressure rises upstream, and the extreme cold air advection will ensure the front moves rapidly.  There will be post frontal showers and storms as forcing from the upper level system will still impact the area later this evening into pre-dawn Friday with showers and thunder late into pre-dawn Friday.  Some pockets of moderate to occasionally heavy rainfall may occur but flooding threats will be mitigated due to the progressive nature of the system. 

 After we rid of the convective issues, the blustery weather kicks into high gear with the coldest air of the season rolling across the nation.  And we’ll get a taste with Friday morning lows in the lower 40s along with northwest winds from 20 to 25 mph.  Two weeks ago, we were tracking heat index values near 100.  Friday morning I’m anticipating wind chill values in the upper 20s and lower 30s across northern OK.  Clouds will linger for the first half of Friday with highs staying in the lower 50s.  Around early afternoon, clouds will quickly clear with late day sunshine as the winds will relax by evening setting the stage for a cold Friday night football game.  Games will be in the 40s. 

Saturday morning will present a nearly perfect radiational cooling impact.  This allows any incoming solar radiation we receive Friday to exit the boundary layer by Saturday morning with a surface ridge of high pressure and light winds nearby.  If the sky remains clear, and it should, Saturday morning will feature lower to mid-30s area wide with a light frost likely.  A few spots will briefly touch freezing.  Once we get past 9am Saturday, we’re off to the races with great weather for the weekend with Saturdays highs in the mid-60s and Sundays highs in the lower 70s. 

Our next front will move across the area Monday night into Tuesday with only a wind shift.  The upper air pattern may support a very dynamic looking upper level system by the following weekend. 

Thanks for reading the Thursday morning weather discussion and blog.

Have a super great day.

Please remain aware of your weather surrounding later this afternoon and early evening.

Alan Crone