Short-Term Forecast Summary
The parade of the maybe clippers! I put maybe in there because these next two systems are well, unimpressive, for now. Clippers by definition are fast movers and they tend to be moisture starved. These upcoming ones definitely fall in that category. Any snow that does fall from them will be light and accumulations are mainly expected in the mountains, but there can be surprises as we saw this morning, especially in snow-deprived Southern Maryland. The next clipper is scheduled to arrive on Friday night. Rain showers are possible beyond 8pm and mixing with snow after 10, lasting to about 3am Saturday or so. Given how moisture starved this system is accumulations of well less than 1″ are expected across the area. Best chance of seeing accumulation is west in the mountains. It clears out Saturday, and then the second snow shower event occurs overnight, as weak as the one that precedes it.
Tomorrow: Partly cloudy for much of the day, with increasing clouds later. Highs in the mid 40s
Tomorrow Night: Rain showers then rain/snow showers. Lows around 30
Saturday: Clearing out through the day with highs in the mid 30′s
Saturday Night: Increasing clouds and a chance of snow showers. Lows upper 20s to around 30
Sunday: Mostly sunny, highs in the low 40s
Looking into the extended range…will give you goosebumps. Another southward incursion by the polar vortex seems likely and this time it looks like it will last longer, but it doesn’t have the same model presentation with threatening wind chills and sub-zero temperatures. The incursion begins on Tuesday Night and could last some time.
Take a look at this map. This is the temperatures modeled by GFS a couple thousand feet off the ground with an established flow directly from the Arctic
That’s cold, but neither the temperatures nor wind chills are as cringe-inducing as the last time we dealt with the polar vortex.
For instance, GFS highs on Wednesday…cold, but not cold that threatens to freeze your hands off with highs in the mid-10s to 20. Full disclosure, now it could go there, but it’s not indicating that yet. As I’ve said previously, this next cold shot looks less intense, but longer lasting than the one we just had. So we win there, but that taxes the infrastructure a lot more, so be aware of that.
This cold also shows across models so in response CPC has painted our area for a high chance of below normal temperatures next week and into the week after that as well. That’s a high confidence forecast from them, so it deserves attention
This represents a big change in the pattern. The pattern, which has been relatively fluid and transient, could just lock in place, delivering us a prolonged period of cold lasting at least through next week and possibly through the end of January. This does not necessarily mean our snow chances go dramatically up, as arctic air outbreaks are usually dry air outbreaks as well. Nothing right now screams big storms but when the pattern starts taking on this configuration…storms can become more likely and it becomes easier for them to produce snow, they’ve got cold air to work with. I think there will be multiple chances for snow events, but most of these should be on the lower end of the scale (clipper trains).
Euro and GFS are hinting at something bigger coming up at the end of next week but that’s long-range fantasy storminess for now. Will keep you updated on the incoming cold.