Would you believe temperatures so far this month are running nearly 6 degrees cooler than normal despite that 10 day stretch of warm, spring-like weather a week ago. Not only that, but so far this is the driest Jan-Feb on record for Tulsa. We do have a chance of rain first thing Friday morning, but amounts are expected to be rather light and probably will not change that status. Friday will also be much warmer with gusty southerly winds and temperatures well into the 50s if not some low 60s by the end of the day. The morning clouds should be clearing out during the afternoon with at least some sunshine, so a relatively balmy end to the month of February.
However, March will come in like a lion with another strong cold front entering the state Saturday and finally sweeping on through the state by early Sunday. This boundary will hang up for awhile creating quite a contrast in temperatures with the more southern counties likely in the 60s or perhaps even lower 70s while the more northern counties will be in the 30s to lower 40s. Cloudy skies will be the general rule as well along with perhaps some drizzle.
Saturday night into Sunday is when it gets interesting. I really thought we were through with any more arctic air this winter, but it appears that is not to be the case. Another surge of extremely cold air will be pushing southward Saturday night and the source region for this air is above the Arctic Circle. This cold air is also very shallow which means the air above it will be quite warm. Notice the temperature profile on the right, which I have used in the past. It is applicable again for this event with very warm air over the top of shallow but very cold air. The way things stand right now, it appears that the event will start off as freezing rain, then as the cold air deepens transition over to sleet. That can be expected for Saturday night into Sunday morning. Later Sunday into Sunday night, there is the potential for enough cold air aloft to arrive before the moisture moves out for another transition to snow or a wintry mix. Elevated surfaces will likely become ice covered quickly and then there is the potential for snow on top of that. Not a very promising scenario no matter how you look at it.
Temperatures will stay below freezing all day Sunday. Keep in mind, the system responsible for bringing the threat of precipitation is currently out over the Pacific Ocean, so there continues to be a great deal of uncertainty since it has not as yet entered our observational network. For example, the NAM has a much drier solution, particularly with respect to the snow potential late Sunday whereas the GFS is much more aggressive and the EURO would appear to strike a middle ground. Unfortunately, there will likely be some flips in the data until we get a better observational sample and that will not be until Friday night or so.
At any rate, early next week will remain quite cold and in fact temperatures will probably not get above freezing till Tuesday afternoon. Another system could bring a threat of precipitation on Wednesday but let's get through the weekend becoming too concerned about that one.
So, stay tuned and check back for updates.