Snow Saturday NIght, Then Brutally Cold.
Saturday night into Sunday morning is starting to look more interesting with respect to our snow chances and the early part of next week still looks brutally cold. In fact, if the most recent projections regarding snowfall come to pass, then we could certainly be seeing temperatures the like of which we have not had around here since early Feb of 2011. There are several factors to be considered before venturing too far in that direction not the least of which is the amount of snow that may fall.
One of the numerical products that we rely on has the greater amounts confined to far NE OK with most of this area in the dusting to perhaps 1" category. However, this is by no means certain and some of the other numerical products are much more generous with the snowfall projections and would suggest 4" or more for much of the area as shown on the map to the right. Current thinking is the truth will be somewhere in between with 1-2" and perhaps locally more in the Tulsa metro and 2-4" with locally higher amounts for the more NE counties. Obviously, those numbers are subject to change.
The timing is dependent on the arrival of the cold air and the initial surge of colder air will be arriving during the afternoon and evening hours of Saturday. That means much of the day Saturday will be fairly decent with brisk southerly winds, cloudy skies, and a chance of drizzle or a few light rain showers. Temperatures will likely be at or above freezing to start the day and should make it into the low-mid 40s before the winds shift around to the north and the colder air starts rushing in. Look for the rain to be changing to snow well after dark Saturday night and then quickly ending from W-E Sunday morning, so this will be another quick hitting system. There will be a brief period in which some sleet or freezing rain may occur before the transition to all snow takes place. All the precipitation should have ended by Noon Sunday and we may even see some breaks in the clouds that afternoon.
However, the coldest air in nearly 3 years will then be surging our way Sunday night and Monday and depending on how much snow is actually on the ground we may end up setting some records. Temperatures during the day Sunday will generally be in the teens or low 20s at best with wind chill values into the single digits. The questions regarding how cold it will be Monday morning are related not just to how much snow we have but also to the wind and any lingering cloud cover. Right now, it appears we will still have a rather strong NW wind through the morning hours and there may be some lingering mid-level clouds as well. If so, that will act to keep temperatures from totally bottoming out. Even so, single digits are anticipated and the gusty NW will likely put wind chill values well into negative territory.
Despite lots of sunshine, an extremely cold, surface high pressure ridge will be settling over the state during the day so daytime highs will only be in the teens. In fact, the strength of this high pressure ridge looks to be comparable to the Feb 2011 event mentioned above and that surface map is the second one on the right to provide some perspective. We don't often see high pressure ridges of that magnitude this far south.
These shallow, cold, arctic air masses are typically rather slow to move out so have kept temperatures much colder than the guidance would suggest through at least Wednesday. By then, we will have a deep southerly fetch and some energy aloft coming this way which may combine in such a way as to provide another opportunity for some wintry precipitation before it all changes to rain. Rain chances may well extend into Thursday and perhaps Friday as well.
Bottom line is some very winter-like weather will be returning late Saturday and will last till the middle of the following week.
So, stay tuned and check back for updates.