Once again, an interesting weather forecast for the next couple of days as we will have at least a couple of chances for additional snowfall. The first chance will be tonight and into the day Thursday when a rapidly moving storm system aloft will be moving across the state. Its preliminary impacts are already being felt as what sunshine we had this morning has already been replaced by increasing cloud cover this afternoon. The air is quite dry at the surface and aloft so this system will not have a lot of moisture to work with but on the other hand that may produce rather high liquid:snow ratios. The general rule of thumb is 10:1 or 10" of snow equates to 1" of liquid. However this event may well be more like 20:1.
Why is that important you ask? Well, typically we translate the liquid precipitation that is anticipated into a snowfall forecast so if only .1" of liquid is anticipated that would translate into 1" of snow. However, since this is a drier system it will be more of a powder that will fall and may take twice as much snow to produce the same amount of liquid equivalent. So, if this next system was to produce 0.1" of total liquid, that would translate into a 2 inch snow. Obviously, it does not take much of an error in the expected liquid equivalent to result in a rather large change in the amount of snow that will be on the ground. Also, the main impacts of this system now appear to be along and south of the I-40 corridor for later tonight, through Thursday morning, and quickly ending from W-E that afternoon where an inch or two may occur.
Another system will be rapidly following on the heels of this one with another chance of flurries or light snow later Friday and through Friday night. This will be another quick hitter with only light accumulations anticipated. Another inch or so of snow will be possible with that system for those locations that receive any snow at all. All in all, not enough snow from either system to cause any major issues, but still enough to perhaps create some local travel problems.
It looks like a break in this active pattern just in time for the weekend, but additional systems are lined up to the west in the upper level flow to bring more rounds of precipitation as we go into next week. Notice the 7 day QPF map on the right. Most of that projected precipitation will be due to stronger systems that are currently projected for early to mid next week. Also, given the much below normal temperatures that will prevail throughout this forecast cycle, some of that will likely be of a wintry variety. Far too early to say what type, where, and how much; just that next week could also be very interesting.
Speaking of temperatures, the bitter cold air in place today will be slow to erode. Notice the high/low map on the right, courtesy of the OK Mesonet. When you factor in northerly winds up to 20 mph or more with those kind of temperatures that results in dangerously low wind chill values and a wind chill advisory remains in effect through Thursday. In fact, as you look at the forecast, it is obvious that we will be way below normal throughout the period. Notice the National SnowCover Map also on the right and you can see there is a lot of snow just north of us as well as the lighter amounts we now have and which may be augmented over the coming days. In other words, temperatures will remain well below normal well into next week the way things are looking now. In fact, some more single digit morning low temperatures are likely along with the cold daytime highs and the dangerous wind chill values on any given day.
So, stay warm, stay tuned, and check back for updates.