January Ending Like a Spring Month

After an 8-day stretch of below-average temperatures, a weather pattern change may bring you Spring Fever by the end of this week.  We’re not even halfway through the cold season yet so it’s too early to think we’re done with the worst of winter. However, this mid-winter reprieve will feature about the best weather you can hope for this time of year.  And, yes, this weather pattern also has an end in sight.

                I’m going to start with something kind of technical: the Arctic Oscillation (or AO for short). It’s a measure of the northward/southward displacement of the polar jet stream that encircles the North Pole. When it’s negative, the winds in the jet stream are weaker and the jet stream is prone to dipping to more southern latitudes. When it’s positive, the winds are generally stronger and the jet stream resides closer to the Pole.  Basically, with a less wavy jet stream, you have the Arctic air locked up in the Arctic.  That will be the case as move into the next week and half or so. In the attached map, you can see the trend for it to go from strongly negative (corresponding to our mid-month cold spell) to a positive AO (corresponding to our late month “heat wave.”) Neat, huh?

So, with the jet stream lifting north and ridging overheard, that opens the door for unseasonably warm air to spill northward into the central and southern Plains. South winds return on Wednesday and we’ll see that general southerly flow until early next week. A steady warm-up ensues. 50s on Wednesday. 60s on Thursday. We might even hit 70° by the weekend! The first attached map shows the warm air over our region displayed from the GFS model.  The second map shows the temperature anomalies… or how much above normal those readings are compared to the daily normal.  It’ll still get chilly at night, but our last night near the freezing mark will be Wednesday night until midweek next week.

A deepening trough to our west early next week will bring a strong storm system our way. This pattern change will put an end to our warm spell. January will end on a near-record warm note and February will begin like April, but shortly thereafter, the door will open for Canadian air to spill southward yet again. After all, the AO projections go back to neutral or negative into February, indicating a southward dip in the jet stream. The passage of the upcoming storm system could bring showers or even a few thunderstorms late Monday or Tuesday. We can’t rule out some wrap-around snow following that as well, but the computer models have not consistently shown much precipitation over Oklahoma with the passage of this storm system.

Soak in the sunshine and growing warmth this week. We’ve still got another 53 days before spring officially arrives.  Be sure to follow me on Twitter: @GroganontheGO and on my Facebook page.