The 24 hour temperature trace on the right for Tulsa shows clearly when the clouds moved in during the overnight hours as temperatures bottomed out near midnight and then started rising. It also shows the effect of the sunshine that broke through the clouds this afternoon and brought us into the 70s. Any sunshine, or lack thereof, will also be a significant factor in our weather on Thursday.
With a major storm headed our way, conditions now favor overcast skies and little or no sunshine except for the extreme SE counties of our state. That will also be the more likely location for greater instability and a greater threat for severe storms. Having said that, there is still at least a slight chance of severe storms just about anywhere in the eastern half of the state for later tonight and through the day Thursday. The low level jet is expected to crank up overnight which could produce some marginally severe hail or gusty winds.
During the day Thursday, a cool front will have arrived to just south of the I-44 corridor by early morning and a surface low will be moving along that boundary during the day. The warm sector and thus the greatest instability is expected to be SE of that feature, but any subtle changes in the movement of the surface low could move the severe threat further north or south. It will be close and the bottom line is that we expect widespread rainfall by later tonight ending from the west Thursday afternoon with embedded storms capable of reaching severe intensity. Temperatures will be strongly influenced by the location of the frontal boundary with 60s and 70s south of the front and 40s to near 50 behind the front.
Friday and Saturday should be quiet with partly cloudy to at times mostly cloudy skies and somewhat cooler conditions. Sunday is shaping up to be interesting though as another strong storm system will be coming our way and could produce another round of storms.
As always, stay tuned and check back for updates.