Wednesday, 11:45 a.m.
Today is a relatively quiet day across the country. The biggest feature, if you wish to call it that, is the one that brought a dusting to an inch or so of snow to southernmost Wisconsin and northern Illinois overnight and this morning. The snow is still falling as I write this across northern Indiana and northern Ohio into southern Michigan, but snowfall amounts are light. The problem with the snow is that it is so cold that it's having no trouble sticking to the ground, which means many road surfaces are slick. The snow will move across northern and western sections of Pennsylvania later this afternoon and tonight, as well as upstate New York and northern New England. Eventually, though, what's left of this feature will morph into a lake-effect/upslope snow event overnight as the arctic air drills over the wide open lakes. As I stated yesterday, someone in the lee of Lake Erie and Lake Ontario could well wind up with more than a foot of snow through tomorrow night and into Friday.
Here's an amazing stat: over 60 percent of the country has some degree of snow cover this morning! Take a look:
Compare that to one year ago:
With all of the arctic air on the playing field and one large surface high after another coursing through the pattern, there's just not much modification take place of these air masses, unless you can get a sustained wind from the Gulf of Mexico to develop. And the upcoming storm this weekend is not really going to qualify as producing a sustained wind off the Gulf!
The air mass now drilling across the Dakotas into the Midwest is brutally cold. Check out the 850mb analysis this morning:
The overnight lows were impressive in the northern tier stats into south-central Canada:
This air mass won't be quite this brutal as it reaches the Northeast tomorrow, as the 510dm thickness line only gets to southern Pennsylvania and New Jersey, and the sub-500dm thicknesses are largely reserved for northern New England. Still, it's going to be very, very cold across the Great Lakes to New England tonight through tomorrow night. The projected daily temperature anomalies tomorrow:
By Friday, the cold will be easing. You might even say retreating, but that might be construed as it giving up a lot of ground. It will be peeled back some, but it's still going to offer up some resistance to the advancing warmth and moisture from the Gulf of Mexico Friday and Saturday. And therein lies the seeds of trouble for the weekend.
Much like what we saw Sunday and Sunday night, an initial weak area of low pressure appears destined to move into the Ohio Valley. As it does, it will carry SOME warmer air along for the ride, but at this juncture it would appear to be less than what was saw Sunday and Sunday night. That means the transition line from snow to something other than snow is not likely to get as far north this time around, and that could that mean more snow for some places.
The 12z Dec. 11 GFS forecast appears to be trending in the direction of the European model, and that would mean a secondary area of low pressure developing in the Carolinas Saturday, then scooting off the mid-Atlantic coast Saturday night and spreading heavier precipitation ahead of it. The warming on the GFS is still stronger than any other model, including the NAM, with the strongest warming aloft set for Saturday night. Here's the 90-hour forecast of 850mb temperatures:
Because this arctic air mass will be relatively stale - in other words, it will not be freshly arrived as the storm is moving in - there should be less icing overall. It won't be non-existent, but it should cause fewer issues overall, especially from the southern Plains and Mississippi Valley into the mid-Atlantic states.
While it's not currently part of the forecast package, I do wonder if there will be another 'burst' of warm advection snow on the front side of this across parts of the mid-Atlantic, spreading up into southern New England. That would likely occur Saturday afternoon into Saturday night if it does, but there's not necessarily a lot of support for that idea - yet. My concern, though, is if the secondary storm takes over quickly enough, there may be enough forcing and overrunning moisture to cause it to happen, and it would be across parts of Maryland, Pennsylvania and New Jersey through southeastern New York into southern New England.
Farther north, where it is all snow, it will be a decent snowstorm, though probably not a major one. It is likely to be enough to cause disruptions Saturday and especially Saturday night into Sunday morning from Massachusetts northward and across upstate New York and northern Pennsylvania. In that broad area, a solid 3 to 6 inches would seem likely, though locally higher amounts are certainly well within reach. More on snow potential tomorrow as the storm draws near.
Behind the storm? Yep, you guessed it. More arctic. The supply is seemingly endless right now, and until we completely drain the arctic reservoir, it will always be a threat to the pattern. And I don't expect that tank to be emptied until say, late April or May!
On a final note, today is the 90th birth anniversary of my mom. She passed away some 17 years ago, but she still is an influence on me to this one. Of the biggest things I do in tribute to my mom is make her holiday fruitcake - with or without fermented beverage! And as I bring it to new places each year for people to sample, more and more people are actually changing their minds about fruitcake! If it is made right and with the right ingredients, it is moist and oh so delicious! Not exactly the healthiest of dessert treats, but I like to use them as 'power bars' in the middle of a day of endurance training! They have the exact same impact, and they are soooo much more tasty! Thanks, mom! I'll be putting the next batch in the oven tomorrow in your honor!
Two systems will delay the onset of warm weather in the Ohio Valley and the East over the next week or so, but then it should get warm all across the country heading into the Memorial Day weekend.
A turn to much colder air over the Northeast and mid-Atlantic states will set the stage for a rain and snow storm later this weekend before it turns much warmer later next week.
It's warm now, but will turn much colder this weekend, with a storm threat later Saturday into Sunday. Warmth will return by the second half of next week.
Though it is cold now east of the Mississippi, with a couple of opportunities for snow into the weekend, a blast of warmth is due for much of the country east of the Rockies next week.
Warm air will once again surge eastward from the Plains to the East Coast this weekend and early next week. A strong storm next Tuesday and Wednesday will then be followed by colder air later next week.
A storm in Southeast Texas will generate severe thunderstorms this afternoon and tonight, and some wet snow on its western flank as it heads into the Ohio Valley tomorrow.