Wednesday, 11:30 a.m.
Today's post will be short and simple. It will deal with all of the cold air that has been shivering Canada for weeks now, with that cold air extending into Alaska until the past few days. Since the weekend, it has been rearranged, with the coldest air now over northern Ontario. When I analyzed my morning weather map, the coldest spots on the map were underneath high pressure that stretched from northwestern Ontario through northern Manitoba into the Northwest Territories. A little piece of that cold air mass bled into North Dakota into Minnesota overnight, but it's already retreating back to the northeast.
On the same weather map, there was also an area of low pressure in Montana. As it darts eastward, it will draw another little chunk of the remaining arctic air southward behind, reaching Montana and North Dakota into northwestern Minnesota tonight. However, if you look at the jet stream flow, there's too much west-to-east flow aloft over the northern Plains, and it's hard to drill cold air very far south under a flow regime like this:
Some of that cold air will slide across the upper Great Lakes tomorrow night and into northern New England later Friday and Friday night. It will offer up enough resistance to the approach of warmer air associated with a storm heading for the Great Lakes late Saturday and Saturday night, so that there can be some snow and ice across upstate New York and northern New England on Sunday and into Sunday night.
Beyond that, I don't see a high of even this magnitude in the pipeline for a while, and it's not like this 1024mb that grows into a 1034mb one by Saturday over Quebec is very strong to begin with. It's not. I saw one Saturday when looking at a synoptic plot that was nearly 1060mb over northeastern Asia! And if you've been studying world wide weather at all, then you'd know just how brutal the cold has been in significant chunks of Asia in recent weeks! That said, there's nothing remotely close to that strong in Canada in the next 10 days.
That makes it hard to drain cold air southward with any vim and vigor. Notice that as we get to the weekend, the frigid air is forecast to return to Alaska and the Yukon Territory:
Some of that bitter air drains into British Columbia and Alberta by midweek:
However, where's the high to drill it farther south? There really isn't one. Furthermore, the jet stream later next week still has a lot more west-to-east in it, if you at the GFS spaghetti plot for Wednesday evening next week:
It should be noted that on that image there's a distinct feature off the Northeast coast by Wednesday evening, a storm that will impact the mid-Atlantic and Northeast with rain and potentially snow next Tuesday and Wednesday, as we've been hinting at for a couple of days now. Nothing has really changed with it - snow is still in the discussion on the northwest side of the storm. And that's not against all of what was said above, either.
If you look at normal temperatures for the latter half of December, they're plenty low enough now for even a normal air mass to yield snow under the right circumstances. Even though there's no appreciable arctic air and nothing to suggest a mechanism to transfer it bodily southward, it just has to be 'cold enough,' and that can easily happen with a storm tracking south of a given location.
That spaghetti plot is making me hungry. It is, after all, Wednesday. And if you're from the Northeast and you're my age, you remember those commercials from the '70s and early '80s. Today, being Wednesday, is 'Prince Spaghetti Day.' Ahh, that brings back memories! Time to go home and make some spaghetti!
Much of the country from the Plains to the East Coast will have several more days of very cool weather. Meanwhile, Odile is threatening Arizona and New Mexico with flooding rains later this week.
A strong storm in Quebec combined with a very large high near Montana will result in sweeping changes across the Ohio Valley into the mid-Atlantic and Northeast in the next 24 hours.
The latest surge of heat and humidity into the Midwest will spread to the East tomorrow but be trimmed back to the South later this weekend by the passage of a cold front.
Summer's heat and humidity will still have a period of time to sizzle the rest of the week into the start of the weekend, but a fall-like air mass will invade the northern Plains and Midwest this weekend.
Even though fall is but three weeks away, summer heat and humidity will have a full run this week from the Plains to the East Coast.
The steamy weather from the Mississippi Valley to the East Coast today will be trimmed only slightly behind a cold front tomorrow into Wednesday. It will heat up again late this week.