From Warmth to Winter We Go

December sure isn’t feeling quite like… December. With highs near or at 70° over the last couple days, we are kicking off meteorological winter on about the warmest note possible. We’re not alone in the lack of winter conditions. Less than 10% of the Lower 48 is currently covered in snow and most of that 10% is at high elevations. See for yourself, below. However, that is about to change in a big way this week.

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                We’ve got one more day of unseasonable warmth before the temperature tumble begins. A strong cold front late Monday will put an end to Indian Summer. In will come the colder air, but between the warmth and wintry air comes a little wetness. Moisture levels will continue to increase Sunday night into Monday morning, allowing for record warm lows in the 60s to begin the day. Light drizzle and showers are possible through midday. Despite widespread cloud cover, temperatures will climb into the 70s for most of eastern Oklahoma before the cold front arrives Monday afternoon.

                Showers and a few storms will be sparked along the front. Its timing will likely determine whether or not Tulsa sees any appreciable rainfall. Most of the activity will be confined to areas southeast of I-44 with a high likelihood of at least a brief downpour from far eastern to southeastern Oklahoma. While instability will be lacking, the powerful winds and shear associated with this storm system might be enough to create locally damaging wind gusts, small hail and perhaps even a brief tornado spin-up (more likely to the east in the Ozarks though). From 3pm to 10pm, we’ll be tracking this threat. Rainfall will be welcome news as our drought grows more severe over much of the area. The fast-moving nature of the system won’t allow for amounts much over .5” in most areas though. Below, you'll see a computer model depiction of tomorrow evening's storm activity.

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                Behind the front comes gusty northwest winds and drier air. This will enhance fire danger Monday afternoon northwest of I-44. The air will grow colder into Tuesday morning, dipping to near freezing in northeast Oklahoma. Clouds and continued infiltration of the cold air Tuesday will keep readings at or below 50° during the day. By Wednesday morning, we’ll have 20s on our thermometer. In just a day and a half, we’ll go from near-record warmth in the 70s to sub-freezing readings. That’s Oklahoma for ya!

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                The cold, dry air settles in for the rest of the week. In fact, a deep trough in the jet stream becomes entrenched over the eastern U.S., sending a conveyer belt of cold fronts our way. (See map above) This appears to be the case all the way into mid-December. Due to the predominantly northerly winds associated with that for us, moisture is not likely to return from the Gulf of Mexico anytime soon. Therefore, this is also a very dry pattern setting up for us, shown below. Snow-lovers are likely going to have to wait at least deeper into December before those chances show up. The one exception might be late this week (Thursday), a few flurries could be flying thanks to one of these incoming cold waves.
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                In any case, the time for coats is coming and it appears we won’t return to this current level of warmth anytime soon. It should begin to “feel” like Christmas fairly soon. Be sure to follow me on Twitter: @GroganontheGO and on my Facebook Page!