We don’t normally put heat and Halloween in the same sentence here in Oklahoma. If there were any year for that to be the case though, this year might be it. Tulsa has had only 5 October days with below normal temperatures and Halloween will fit right into this unseasonably warm trend. In fact, this month will likely go down as the 5th warmest October on record for Tulsa.
While we may be just shy of the 87° record high, this will likely be the warmest Halloween Tulsans below retirement age have ever experienced at home. This warmth is thanks to the continued presence of an upper level high pressure and southerly winds at the surface, reinforcing the air mass that is normally displaced far to our south by now. The jet stream is still streaming along quickly from west to east without any major shifts southward to bring that colder Canadian air our direction. We did see on Sunday how much even a weak cold front time of year can disrupt the warmth however from Tulsa northward.
Monday’s return of strong southerly winds will be maintained into the month of November. This warm spell clearly doesn’t know calendar boundaries. However, clouds will be on the increase Tuesday as our next storm system draws near, limiting that warm-up just a bit. By Wednesday, showers will break out in the return flow of moisture as the upper energy starts to push overhead. The associated cold front will likely arrive Wednesday night with our best chance of rain and storms. And by Thursday morning, we can finally breathe in that fresh, cooler fall air. Here's that midweek jet stream set-up seen from the EURO computer model on Weatherbell's display below.
The cool-down for the second half of the week won’t be very dramatic as temperatures will still be slightly above normal. In early November, the average highs are in the upper 60s and the average lows in the mid-40s. You wouldn’t know it, but we are sneaking up on our average first freeze date by the weekend. We will be nowhere near those cold readings by that point this year. Still, another stretch of mild days and cool night are expected with generally clear, dry weather.
The only kink in that plan by the weekend may be the approach of a slow-moving cut-off upper level low. That low splits off from the jet stream early this week and sits and spins its wheels over the Desert Southwest for quite a while before getting the boot eastward. That could bring some showers our way by Sunday, but no heavy rain totals are expected once again. Instead, our drought will hold steady at the best or even worsen as we head into November. The most recent Drought Monitor is shown below.
Looking deeper into November, the computer models hint at stronger storm systems shifting into the Plains that would draw cold, Canadian air southward. However, the signal lies out beyond the reliable range of our forecasts. Should that trend continue though, that second weekend of November could bring a serious chill to our state. Between then and now, the Outlook below from the Climate Prediction Center will likely be the ongoing story, not just for us, but much of the country with colder weather on hold.