Tracking Two Weekend Waves

Thursday, November 13th 2014, 4:32 am

By: Alan Crone

The cold air will remain through the weekend and into the first part of next week before finally moderating as it moves eastward. We're tracking two systems that may impact the state this weekend with some precipitation, including the probability of some wintry precipitation over portions of the state. Any snowfall or winter mix is expected to be very light across northern OK with minor impacts.

Temperatures this morning remain in the lower 20s for many locations along with north winds creating wind chill values in the teens. Afternoon temperatures will move into the lower 30s with a sun-cloud mix.   No significant change is expected Friday with similar conditions. Friday night football games will be played in the lower 30s.

The arctic ridge of high pressure continues to build southward while the main upper level low over the Great Lakes and Midwest combines to open the gate for polar air flowing southward into the nation. The main upper level “blocking pattern" will continue to exist through the weekend before the pattern begins to change next week. A series of waves will rotate down the upper air flow across the state this weekend with some chance of a rain-sleet-snow mix Saturday and all snow Sunday. The exact coverage and amounts will continue to be refined as we approach the weekend, but the overall impact appears minimal for most locations.   Many locations across the state will not receive any precipitation this weekend.

The first wave will approach from the west Saturday morning across far northwestern OK. Precipitation will break out in these areas of the state in the form of some light snow. As the wave progressives east to slightly northeast, additional precipitation is likely across Kansas in the deeper and colder air mass supporting all snow. Southward into central OK, the temp profile may support an early snow or sleet mixture before changing to some very light rain by midday to early afternoon. At this point, surface winds are expected to be from the southeast. Some accumulating snowfall is likely across central Kansas into southeastern Kansas and possibly along the OK-Kansas state line region Saturday afternoon and evening.    This wave will then move east taking some precipitation across far northeastern OK and northwestern Arkansas Saturday night in for the form of a winter mix.   This first wave may barely brush the Tulsa area with a small area of wintry mix by late Saturday afternoon.

Sunday another wave approaches from the west which will drive another surface boundary (cold front) southward into the state bringing another reinforcing shot of cold air into the region along with gusty northwest winds. Model data continues to support some snowfall potential (light snow) across west-central or central OK with the possibility of a few snow bands into northeastern OK.   There is some potential for a swath of 1 inch snowfall across west-central OK but any amounts across the north or eastern third of the state will remain less than 1 inch, and possibly just a dusting. I will also continue to stress the probability for precipitation remains relatively low for many locations across northern, eastern, and southeastern OK. Many locations may not receive any precipitation this weekend.   The best chance for northeastern OK to receive winter precipitation appears to be Sunday afternoon or evening.   The timing for both events this weekend may continue to undergo changes.

The cold air-mass will remain Monday into Tuesday morning before finally moving eastward allowing for some mid to upper 40s to populate northeastern OK by the middle of next week.

Thanks for reading the Thursday Morning weather discussion and blog.

Have a super great day!

Alan Crone

KOTV