Widespread rainfall with some embedded thunderstorms still look to be a good bet for later today through the night tonight and gradually ending from W-E during the day Sunday. At the same time, colder air at the surface and aloft will be moving back over the state Sunday bringing with it the possibility of a wintry mix. From the first map on the right, you can see that soil temperatures have warmed up nicely and since air temperatures will stay above freezing during this event, then it will be mostly just a cold rain and what wintry stuff may mix in will not accumulate.
However, this does appear to be a rather wet system with the potential for our first widespread, soaking rain event in several months. In fact, you have to go all the way back to early November for the last time we had as much as 1" of rain in Tulsa. From the 2 day QPF map on the right, you can see that we stand to receive a good bit more than that as 1-2" should be common and some locations may receive more. As mentioned, some thunder can also be expected but this does not appear to pose a threat of severe weather although some small hail may occur.
Temperatures will be mild today with afternoon highs reaching well into the 60s before the rain moves in. SE winds of 10-15 mph and increasing cloud cover also mean higher humidity levels which will mitigate the fire danger before the rains arrive later this afternoon. The rain will then be widespread during the overnight hours and our winds will shift to northerly and increase to 20-30 mph with higher gusts. So, this will be another windy system and those strong northerly winds will drop temperatures from the mid-upper 40s first thing in the morning to perhaps the upper 30s at times before recovering to near 40 late in the day. Together with the strong northerly winds and moisture in the air, it will certainly feel much colder.
Sub-freezing temperatures along with light winds and clear skies will start the day Monday but with the winds quickly returning to a southerly direction, temperatures should rebound back into the 50s if not near 60.
Another frontal boundary will be pushing across the state Tuesday with gusty southerly winds shifting back to northerly by days end. This looks to be a dry system and temperatures ahead of the wind shift should be close to 70. Wednesday will then be a bit cooler with highs near 60, then a return to southerly winds will bring daytime highs back to near 70 Thursday and into the 70s by Friday. By the way, according to the calendar Spring officially begins this coming Thursday and the Mon-Fri Spring Break period looks rather promising.
So, stay tuned and check back for updates.