We've enjoyed some great fall weather of late, but our cold spells have been getting colder and longer. In fact, some of us had our first frost and freeze of the season. Tulsa narrowly avoided a freeze with a low of 34 on Saturday morning. Another threat of a freeze lies ahead for northern sections of Green Country Thursday night into Friday morning. The average first freeze in Tulsa is actually November 3rd, but we are well within the range of first freezes now. It's definitely that time of year you hear us meteorologists talk a lot about "sensitive vegetation!"
Our forecast features a lot of ups and downs as we lie on the boundary between an entrenched cold air mass over the Midwest and milder air of the southern Plains and Southwest. A cold front will drop our temperatures a good 10° Thursday, but the sunshine will cut back on the cold air.
Temperatures rebound to seasonal norms over the weekend and a weak system will provide us with a slight chance of rain on Saturday, more than likely after the Tulsa Run has ended. The "up" in temperatures continues into early next week as we see a big pattern shift. That entrenched cold air over the Midwest thanks to a deep trough in the jet stream will finally push out as another strong storm system digs into the western United States. That opens us up to strong southerly flow, bringing up those readings and bringing back moisture from the Gulf of Mexico.
With a big storm system set to move in, we can count on a big shift in temperatures yet again. A stout cold front will be a focus for rain and thunderstorms. Following that, cold air arrives yet again just as we make the final touches to our Halloween costumes. It's still over a week out, but the big night for trick-or-treating may be a cold and/or soggy. It's a big system and it will take several days to clear the region. Before that front arrives, however, it'll feel a lot more like late spring. The cool-down may have us scrambling for our winter coats. In any case, it looks like one active weather pattern lacking moisture this week is about to give way to another with lots of moisture next week. The attached map shows a computer model prediction of the upper-level storm system a week from now.