It has been another much colder than normal day, as you can see from the max/min temperature map courtesy of the OK Mesonet. In fact, so far this year temperatures are averaging nearly 9 degrees colder than normal and today makes only the 4th day in which afternoon temperatures even made it to the 40 degree mark here in Tulsa.
Fortunately, the wintry precipitation that developed during the day largely occurred while temperatures were at least above the freezing mark so there have been no issues reported.
This cold weather trend actually started right after Christmas so after more than two weeks now of persistently cold conditions we will finally be getting a break.
Clearing skies later tonight together with lots of sunshine and a light westerly breeze for most of the day Thursday should result in a significant warm-up.
Morning lows will be in the 20s again, but look for our afternoon highs to be in the upper 40s if not lower 50s by days end. Keep in mind, our normal diurnal range at this time of year is 48/27.
Friday right on through the weekend look to be even milder, if not dare I say warmer, as our afternoon highs are expected to be around the 60 degree mark and perhaps even the mid 60s by Monday.
The last time we had those kinds of temperatures was the day after Christmas.
The reason for this is a change in the wind flow aloft.
Notice the 300mb map valid last night at 6pm. This map shows the relative location, strength, and orientation of the jet stream at that level which corresponds to about 31,000 feet above sea level.
As you can see, there is a substantial component of the flow coming down out of far northern Canada and diving deep into the U.S. That is a very amplified flow pattern that has been a persistent feature for weeks now and keeps sending cold, Canadian air our way.
The second map shows the same level but at noon on Monday of next week. Notice the flow is now more W to E or what we refer to as a zonal flow aloft which typically brings milder, Pacific systems our way.
At the surface, we will also have a more S to SW wind component which is also a warm wind for us.
Fronts will come our way from time to time and knock temperatures back closer to normal, but the lack of amplitude should keep the brutally cold air bottled up well to our north for some time.
In fact, if you look at the maps illustrating the average conditions for the 8-14 day time period, you will see that there is a signal suggesting we will be below normal with respect to temperatures and above normal with respect to precipitation.
However, to our north conditions will be closer to normal which suggests that the clouds and chance of precipitation will be the primary cause of the cooler conditions rather than additional outbreaks of brutal cold.
Keep in mind, this pattern can become more amplified again rather quickly so we are certainly not through with winter by a long shot.
So, stay tuned and check back for updates.