Up-and-down week leading way to warmer pattern; also, a little-known MLK Jr. historical weather footnote
This Monday is the federally recognized day commemorating slain civil rights leader Martin Luther King, Jr. As a footnote to history, there is a bizarre weather event connected to the timing of his assassination in Memphis in 1968. King had been scheduled to arrive in Memphis on March 22, 1968, to support striking city sanitation workers. But on March 21-22, 1968, Memphis was hit by its second deepest snowfall on record — more than 16 inches. (Linked here, a photo from that snowfall by the Memphis Commercial Appeal.) Memphis very rarely gets that much snow in an entire winter, let alone on the first day of spring. Because of that freak snowstorm, King was forced to delay his visit to Memphis by several days, and was shot and killed at the Lorraine Motel on April 4, 1968. What would have happened — or not happened — had the snowstorm not happened and King had come to Memphis on the earlier date is, of course, speculative. But this is one of many notable historical events influenced, at least in a small way, by weather.
It appears very likely we are headed into a new weather pattern — and not one snow lovers want, at least in the next couple of weeks. All signs point to Arctic air pooling over the Atlantic and northern Pacific, inducing a large area of high pressure downstream over the lower 48 states, leading to a widespread and significant late January warmup. It’s what we might call a January thaw some winters — but this winter, there’s not much to thaw. This will be different in that the pattern we have had for weeks (arguably nearly 3 months!) has been more progressive, with periods of mild weather occasionally interrupted by rain, followed by sharp cold. Perhaps the first small signal that something new is up is displayed on the 3-day rainfall map from the Hydrometeorological Prediction Center. Notice how the darker colors of heavier precipitation peter out at the Appalachians, with a doughtnut hole of quarter-inch or less amounts in Virginia. That shows a low-pressure system tracking farther west, drawing warmer air into the region for Tuesday but pulling in less of a moisture feed from the Atlantic and Gulf of Mexico like we’ve seen in about half a dozen storm systems that have hugged the Appalachians since November. This time around, we will get a decent punch of Arctic air on Wednesday, and likely a fairly vigorous round of upslope snow showers. But after this shot of Arctic air, we may not see another one so cold for at least 10 days afterward, as growing warmth over the continental U.S. keeps it bottled in central/northern Canada and Alaska.
There is some chance that a few showers of rain may arrive before cold air has fully been eroded Monday night, especially in deep rural valley locations and those with remaining snowpack, so some spotty sleet or freezing rain is possible. Beyond that, temperatures may well shoot into the 50s or even low 60s Tuesday, before crashing back to 20s/30s again for Wednesday. A steady rise in temperatures is expected through the weekend, possibly topping 60 again by Sunday.
I think there’s a pretty good chance we have a day or two with some 70s in the following week. Beyond that, I’m still betting on an Arctic plunge at some point in early/mid February. When Arctic air starts stacking up behind such a large warm air mass in mid-winter, it usually comes crashing south sooner or later.