Wednesday, 11:00 a.m.
The ever-changing nature of the weather continues to amaze me today. Yet another nuance has come to the forefront over the past 24 hours to spell trouble for those in the Northeast looking for a snowstorm later Friday and Friday night into Saturday morning. Oh, there will be a storm. But unlike the concerns from late last week and last weekend of a storm bring too much warmth too far north, we're instead looking at two separate systems than appear unlikely to come together until it is too late for much of the northern mid-Atlantic and New England to get any meaningful snow. If anything, the best snow associated with the end-of-week event may end up south of Washington, D.C. - as in central and southern Virginia and northern North Carolina back into parts of Kentucky and West Virginia. There's something so wrong with that, that is actually seems right in an odd sort of way!
The culprit may well be the feature moving through the Midwest and Great Lakes into the Ohio Valley right now with a lot of clouds and some very, very light snow and flurries. The system may best be seen at 850mb this evening:
If you look at the solid black lines, they show an upper-level trough swinging through the Great Lakes and Midwest. The coldest air aloft drills into Minnesota and Wisconsin behind it, where temperatures will fall this afternoon in the wake of the feature. It will generate some light snow this afternoon into early tonight across parts of the Ohio Valley to the spine of the Appalachians, then later tonight east of the Appalachians over portions of Maryland and Virginia. Snow amounts won't be a problem, but what it may do to the roads could be a real headache for the early morning commute in places like Washington, D.C., and Richmond, perhaps over to Salisbury and down to Norfolk.
That feature, once it darts off the coast early in the day tomorrow, will cause a storm to blow up well off the coast, not unlike what we saw earlier yesterday from a similar feature. That first storm has rolled up through the Northwest Atlantic and will hook by the southern tip of Greenland tonight to end up between southwest Greenland and Labrador by the end of day tomorrow:
Notice that by the end of the day tomorrow, a pretty healthy low has blossomed out of seemingly nothing well south of Nova Scotia. And aloft, that strengthens the northwest flow from the Midwest to the mid-Atlantic:
That sets the stage for the feature coming at the northern Plains and Upper Midwest. It will be starved for moisture, so it won't have a lot going for it. By Friday morning, a weak surface low will be somewhere in the vicinity of western Lake Superior or northeastern Minnesota, while at the same time some warm advection precipitation will be developing from eastern or northeastern Texas up into the Tennessee Valley. Because the low levels will still be pretty cold across southeastern Missouri into Tennessee, some freezing rain, freezing drizzle and sleet may be the concern. Eventually as the precipitation spreads farther northeast during the day Friday, it will run into the deeper cold air, and snow will be the primary form of precipitation. This is where the 700mb forecast chart may show things better. Look at the forecast for Friday evening:
It appears to be one giant area of moisture stretching from the Great Lakes to the eastern Carolinas and offshore, but it's really two separate areas, with the separation between the two in the process of disappearing. In the north, you can still see the upper-level trough moving into the Great Lakes, while the better area of high relative humidity values is moving through eastern Virginia and the eastern Carolinas, getting ready to quickly escape offshore later Friday night.
In essence, these two features not only remain separate, but because they do, the southern branch feature on its own will be unable to turn the northwest flow around enough to allow the developing storm to cut toward the northeast later Friday and Friday night. If the two features were to join forces and a little more slowly, then it would turn to the left more quickly, but that now seems unlikely.
Still, in the end, there should be at least some snow across the Ohio Valley into the mid-Atlantic and southern New England. I have a hard time believing there is no snow in places like Philadelphia, New York City and Boston. It may not be anything more than what has fallen already this week, but for it to be a complete miss is hard to fathom.
Following this weaker 'event,' it will remain cold, as high pressure settles into the East Saturday night and Sunday morning. But once the high leaves, milder air will quickly expand from the southern and western Plains to the Mississippi Valley. The farther north and east the warm air advances, the more resistance it will run into, leading to an expansion of clouds, followed by some ice then rain. In the end, there will be a nice warmup in the Ohio Valley for a while next week, spreading into the mid-Atlantic and New England Tuesday and Wednesday.
Once the storm off the Carolina coast pulls away from the coast tonight, the weather pattern will be rather quiet in much of the country into early next week, and it will also be rather mild in much of the nation. That will all change with a storm during the middle of next week that could dump heavy snow from parts of the Ohio Valley to the Northeast, and it will be followed by another blast of very cold air for the second half of next week into next weekend.
Cold and wintry weather is not leaving any time soon, though there will be a couple of breaks in the cold over the next week that will offer up some spring teases.
The worst of the bitter arctic air is easing over the next 24 hours, but there's still plenty of cold air in the pattern, and there will be a storm next week that may spell trouble as it runs from the Northwest early Monday to the East late Wednesday.
A record-setting cold air mass is in place from the southern Plains to the East Coast today. It will ease later this week, and another of its kind is unlikely, but the pattern remains cold for much of the next two weeks.
In the wake of the winter storm still bringing heavy snow through Virginia, Maryland and Delaware, it will be frigid tonight into Wednesday before the cold eases over the second half of the week.
The major winter storm that will track across the country this weekend is already bringing heavy rain into California. It will bring a lot of ice and snow from the central Plains to the Northeast and parts of the mid-Atlantic states, especially Sunday and Sunday night into Monday.