Tracking A Storm

We're starting with clear sky and cool air but we're going to finish this afternoon with mostly cloudy conditions as moisture rapidly streams northward in advance of a strong storm system.  Thunderstorms are likely tonight across western OK and some of these may moving into our area by early Friday morning.  Additional storms will also be likely Friday afternoon and evening across eastern OK as a pacific type front pushes across the region.  Surface instability will be rather weak but deep layer shear will be very strong.  This may overcome the lack of instability to create a severe weather environment with some of the stronger storms allowing for some hail and damaging winds.   The Storms Prediction Center has a slight risk of severe storms posted for western OK today.  The slight risk area for Friday currently includes the north into central and east central OK.   

The main upper level low will be lifting rapidly to the northeast of the state by Saturday morning and will be near the southern Iowa area by Saturday afternoon.  Some wrap around clouds will be possible across northern OK and southeastern Kansas but very little in the way of precipitation will be offered with the wrap around on the back side of the system for our area.  This type of a system would usually bring winter precipitation to the state, but the trajectory of the upper level system will keep any winter precip confined to northern Kansas and southern Nebraska for Saturday.  Today and tonight, locations across Eastern Colorado and far northwestern Kansas will experience near blizzard conditions as the system brings wintry precipitation to this region during the next 12 hours.   This will be a major winter storm for Eastern Colorado and portions of Northwestern Kansas. 

Temperatures this weekend will be cool for the state but near normal with lows in the lower 30s and highs in the upper 40s and lower 50s. 

The arctic oscillation is clearly in the negative and will be for the next week or two.  This means the very cold air to the north will be moving southward soon.  The trajectory of the upper air flow in some of the extended data suggests an almost cross-polar flow by late next week that would drive the bitterly cold air southward.  But the pattern also supports a quasi- rex block that would keep the very cold air to our northeast, mainly located across the northern high plains into the Midwestern U.S. and the northeast.

Stay tuned.  This could get interesting.

AC