Weather Blog

This weekend has been pretty nice across the country, with little in the way of watches or warnings or intrusions of cold air or wet weather. Unfortunately, it is only late November, and winter is not yet cancelled.

In fact, there maybe a couple of features that bring wet weather and less pleasant conditions to the country this week. First, early this week a feature will come out of the Rockies and move into the Plains, bringing rain, snow and cooler air to the middle of the country.

The feature will shift towards the Great Lakes, with showers and thunderstorms south from the Ohio River, and a real possibility of lake enhanced snow mid week before shifting out through New England late in the week.

A couple of other surges of wet weather will be possible with a feature arriving in the Pacific Northwest on Tuesday, which might lead to some significant problems in the mountains for casual travelers, but probably not those that are used to it.

Late in the week, a system will develop in the Lower Mississippi Valley with cold air driving in from the northwest. It will predominantly be a rain maker, initially in Mississippi and Louisiana, but shifting northeast before clobbering the Ohio Valley again, and eventually the entirety of the Eastern Seaboard. Again, it should all be rain at least through next Sunday, with some thunder further south.

Now, as for the beginning of December. A developing area of low pressure in the mid-Atlantic might make things a bit more wintry. But we’ll talk about that again at a different time.

One aspect of emerging media and is the rapid dispersal of terms that come up in the news. Some things have always been there, and just get out of hand when they enter the news cycle. Things like “bomb cyclone” seem absurd to the point of frivolity if you don’t know the definition. I’ve gotten into debates on Twitter about Particularly Dangerous Situations being assigned to some weather watches, because the other Twitter user thought meteorologists were being overdramatic in their terminology. It’s a lesson in never using Social Media.

One term that really exploded in the last half decade was “Polar Vortex” which emerged in the midst of a persistent cold snap that was particularly cruel to the Eastern Seaboard. Since the East Coast is where most media, and really most of the people in the country reside, the term was foisted upon the country. There were some amusing consequences.

But mostly, it just annoyed meteorologists, because the colloquial definition of the polar vortex is not correct. As the media may have led some to believe, the polar vortex is not just a surge of cold air that dive bombs the mid latitudes out of the Arctic.

A vortex is something that rotates, The Polar Vortex, then, is the Arctic jet that spins around the North Pole. Ergo when it is strong, as is the case with all jet streams and streaks, it represents a sharp temperature contrast on other side of the streak. While it will certainly be cold north of, or within the vortex, it’s strength suggests that it will actually be fairly warm south of it.

Weaker flow can lead to some ripples in the jet, which can mean lobes of cold air pressing further south, particularly later in the year when high latitudes start to get colder on their own. Right now, though, it looks like we have a stout Polar Vortex to guide us into winter, and that is a good thing.

2020 has now surpassed 2005 as the most active tropical season in the North Atlantic in recorded history. We’ve exceeded the total of named storms by two, dipping further into the Greek alphabet than ever before. The long lived Eta has made the most of it’s first appearance in our meteorological lexicon, while Theta is spiraling out by the Azores, and Iota is preparing to landfall in Central America, near where Eta initially exploded on the scene. Similarly, Iota is expected to become a hurricane, with the present forecast asserting that Iota will be a major hurricane upon besetting the Nicaragua/Honduras border with more destruction.

Fortunately, despite all the action this year, we haven’t matched the pace of hurricanes or major hurricanes of 2005, which still holds the record in both categories. A bit of good news is that, at least for the next couple of weeks, it doesn’t look like Iota has a follow up on the immediate horizon, which will make it difficult to reach the hurricane or major hurricane numbers of 15 years ago.

Of course, I say that now, but it should be noted that the Tropical Storm Zeta of 2005, the last storm of that busy year was also the first storm of 2006. In a year like this, there is plenty of time for more new ground to be covered.

Today was a particularly active weather day, with low pressure in the Upper Midwest extending a cold front through the Great Lakes and on towards the Mississippi. The front itself has been the origin of severe weather from the Quad Cities south through Missouri and eventually across Big Muddy and through Illinois.

More indicative of what’s coming is the snow that fell in the Upper Midwest. 2-5″ fell in Minnesota as precipitation wrapped into the cold air diving into the country behind this system, merely a couple of hundred miles away from tornado warnings in northern Illinois.

More tangibly, I think these two images spell out the change coming for the end of the week. First, the radar imagery.

And now, take a look at tonight’s lows. There should be some significantly colder air northwest of those bands of thunderstorms.

And there is that sharp drop I promised. High pressure will move in at the surface over the Plains, and prevent much of a warm up for a couple of days. Eta will slow the cold front so all those places that will get copious rain from the tropics will remain warm few days longer.

If you didn’t believe it yet, winter looks like it is here, and will hang on.

We are only a week into November, which means that we are awarding the forecaster of the month sooner than usual lately, and also, with as long as this week took, it’s clear time has no meaning anymore. The forecasting was pretty ok this month, though it leaned heavily on model guidance because of a west coast bias. It was Accuweather who did the best work for the month.