While we bask in some late-season warmth, the state of Oklahoma continues to dry out. For many locations it has been 40 days since any significant rainfall (back to late September). It's no wonder the drought has worsened in the most recent Drought Monitor. Much of eastern Oklahoma has fallen back into "Extreme Drought," the second-worst drought category. Some of the driest, dustiest locations are portions of Okmulgee, Creek, and southern Tulsa counties. That's why we are giddy about the chance of a soaking rainfall this Sunday.
Until that time, warm, windy weather will prevail. Given the strength of this storm system we are feeling its effects while it still lies over a thousand miles away. A tightening pressure gradient is giving us strong winds, which is transporting that much-needed moisture into the area. Clouds will increase into the weekend, but the rain should be holding off until Sunday morning. There will be strong enough forcing to overcome the limited instability. Essentially, that means the winds at the surface and aloft will be powerful enough to provide a risk of severe storms despite a lack of heating. The main threat with the storms would be damaging winds and the primary area for this would be southeastern Oklahoma with the most daytime heating occurring there.
What about rainfall totals? The attached map above gives us an estimate of total rainfall through Monday morning. As the area of rain and thunderstorms move east and intensify with daytime heating on Sunday, the rainfall totals will go up overall the further east you get. Around Tulsa, we may only pick up a half-inch of rain. Closer to the Arkansas border, 1-inch amounts may be common. It won't be a drought-buster, but it'll be the first significant rainfall in a LONG time. Most everyone should see enough rain to at least settle the dust.
With the passage of the front midday Sunday will come a big-time drop in temperatures. Some of the coldest air of the season will rush into Green Country, giving us the risk of another freeze by Monday morning. After highs near 80 today, a high near 50 on Monday will be a shock to the system. Cool, but rather dry weather will continue into much of next week.