Stormy End to November Followed by a Chilling December
The temperatures are back on the rise this week as close out a roller coaster November. Winter came early for many of us this month after getting an early blanket of snow. Since that time, temperatures have risen into the 60s and even 70s giving us a nice period of Indian Summer before more Arctic air finds its way to Green Country. This warmer spell also comes with a risk of storms by Friday.
Southerly winds over the next few days will help to transport Gulf moisture back into Green Country. As a powerful and fast-moving disturbance in the jet stream arrives from the West, the stage will be set for rapid thunderstorm development late Friday. Exactly where the storms fire and how intense they will be is still the big question at this stage, but there appears to be at least some risk of severe weather as shown below. Here’s our latest thinking.
Low-level moisture may keep us locked into cloud cover for much of the day Friday slowing our warming trend a bit. However, as the main impulse arrives around sunset, the powerful winds aloft and overall wind shear should help to generate widespread showers and storms lined up north to south over the area. These storms could form as far west as I-35, but more likely really get going along Highway 75 (through the Tulsa area) before racing eastward and gradually strengthening as they move into a more unstable environment. While showers may occur earlier in the day, the window of time for heavy downpours and storms is after dark and before midnight for the area. Below is a timeline for the activity around Tulsa.
In this highly dynamic, but low instability environment, high winds are usually a threat. There will be enough low-level spin to generate a few brief tornadoes. However, that threat may not be realized in Green Country, but further southeast in the ArkLaTex in a more unstable environment. Hail could also occur if the cells get beefy enough. Once again, the threat for the immediate Tulsa area is limited at this point, but higher in southeast Oklahoma. The timing sure is not great for the high school championship football games Friday night. The one bit of good news is that these storms will be in and out in short order. Just have rain gear on hand and a way to receive severe alerts if you’re out and about Friday night.
Since this storm system is taking a southerly track across the U.S., it isn’t latching onto Arctic air. This means the weather behind this system over the weekend will remain fairly mild. However, a system early next week will pull down some cold, Canadian air into Oklahoma. This means the first full week of December will be cold one. If we can get a storm system with any appreciable moisture, wintry weather would be a good bet nearby. This pattern may be with us into mid-December before another moderation of temperatures may be in the offing for our region. We are settling into a winter jet stream pattern, which means now through March, we are in the running for snow, ice and the occasional round of storms.