The first chances of snow come in the subway

As we approach the last day of November tomorrow, Mother Nature may be giving us one last day of November snow, and perhaps it will be more than just an occasional amount for parts of the region.

Snow is expected to form before dawn tomorrow, and I’m worried that a streak or two of snow might reach too far and give someone out there a decent accumulation (over 2 inches worth).

This first snow is, for whatever reason, pretty difficult. Where there is heavier snowfall the roads can become slick, and while the focus is more towards the east of the metro, I still have concerns about how this will play out in Kansas City itself. But why?

Because things will develop over or near the KC area, so to speak. So if something comes together around daybreak or to the west of us, it can be a little more problematic in terms of how much we get.

Starting tomorrow morning, the snow will clear and the colder air will stick around for a few more days before we ease off a bit towards the middle of next week.

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Forecast:

Today: Sunny with rising temperatures later in the afternoon. Highs will be in the mid to upper 30s

Tonight: The clouds are getting deeper and thicker. It may snow lightly towards daybreak. Lows will be in the mid to upper 20s

Morning: It may snow in the morning. Accumulations of up to 1″ for most of the metro, with higher totals of 1-4″ possible in some bands toward central Missouri

Sunday: Sunny and cold. Lowest temperatures are around 15° in the morning and around 32° in the afternoon.

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Discussion:

There is still a large discrepancy between models trying to figure out how the bands of snow that should develop around daybreak come together and how thick they are.

I don’t have a good feeling about this and I’m worried that the metro area may get more snow than I’m currently forecasting. At least there’s an upside that shows I’m not trying to sweep under the rug.

Part of my concern is that I see a strange feather-like arrangement on the models just above the surface. This is a low jet stream heading straight towards us tomorrow morning. IF this was spring, there would be conditions for thunderstorms. This build-up tonight and tomorrow will be maximized toward daybreak over the KC area, so to speak, based on some model data released this morning.

IF this was spring or even summer, we would be concerned that thunderstorms could develop over or near the metro before dawn. However, since the air is much colder, the focus is on the formation of possible bands of snow.

Where these bands of snow actually form is typically difficult as there is the potential for higher totals (over 3 inches). However, if they do not actually form, the amounts can be significantly lower or not present at all.

I can see the models fighting this in their output this morning. That’s what makes me nervous. I’m afraid there’s something bigger happening out there than what’s being talked about.

For example, this morning the NAM model had this for the snowfall output:

Note the sharp turnoff near the I-70 corridor. This would be a MAJOR problem and areas northeast of the metro would see 4 to 8 inches of snow. Even the north side of KC is in a band about 2 to 4 inches wide with thunderstorms on the south side.

The GFS has something similar, but not to this extent. Again, the aim is to detect this banded snow (although these models are not that good).

The Canadian…

I’m trying to see these bands again.

And the nightly run of the EURO…

It is important to note that the GFS ensembles, which are a mix of about 30 models with varying outcomes, have lower totals toward the metropolitan area and higher totals toward central Missouri.

That was about my forecast from last night with a potential of 1 to 4 inches toward central Missouri and east and lower totals in the metro area.

The morning run of the HRRR model actually didn’t do anything for us. Maybe a few storms. The HRRR model would normally do better with this, and that’s partly because it shifts the winds above us more quickly from west to east.

Take a look at the comparison of two models. The morning run of the NAM model and the HRRR model. This applies to the wind field at about 5,000 feet. Notice where the wind blows! That would be the area with the best lift.

Now the HRRR model. Notice the difference in the direction the wind is blowing. This is for Saturday, 6am.

This difference is, in my opinion, the problem.

That’s the key to severe weather or more than 4 inches of snow in the metro.

To make matters worse, this is actually not an organized storm moving through the air. It’s basically a series of weak glitches broken down into parts, which doesn’t inspire confidence when dealing with large sums.

There is also A LOT of dry air in front of these features, which must first be overcome. So if the propulsion or buoyancy is weak in places, the dry air is a greater factor in chewing up the falling flakes. But since there are a number of perturbations that potentially increase these areas of buoyancy locally, I believe this dry air can be overcome.

In a way, and perhaps to make a point, I’m thinking about a cup of marbles and then turning that cup over on a table. All these marbles are flying in different directions and at different speeds. In front of each marble there is a “buoyancy” in the atmosphere, and behind each marble the air sinks.

As for the weather, we know that the marbles will somehow move from west-northwest to east-southeast. So that helps a little, but we don’t know how many marbles there are or where exactly they go. We have a broad idea, but not a precise idea, and that is also a problem.

Oh, and there might be some larger marbles in there than smaller marbles, which affect the atmosphere differently.

Here’s how you can see how things can get out of hand…

So what do I think? at the moment? I think the NAM is too aggressive with its snow performance. I may increase the snowfall in the metro from dusty to about 2 inches (up from 1 inch) in the late shows tonight, and by then I’ll be doing the final model runs to hopefully confirm this thought process or not.

I still think there could be about 2 to 4 inches total toward central Missouri. Again, Mizzou fans, pay attention tomorrow morning when planning this trip. Alex will have this information for you.

I think the other model runs have a chance of being more accurate in this case…

What bothers me is the HRRR model and some others that give us next to nothing. Again, I understand why they are so negative about the snow here, and maybe they are right in the end, but I won’t let up here.

I will post a video update around 6:15 p.m fox4kc.com and another late night Update on the website at approximately 11:00 p.m. We have basketball and football tonight, so there are no early newscasts and our late newscasts are 30 to 45 minutes late, somewhere between 10:30 and 11:00 p.m. So it’s a good thing and a bad thing. I’m curious to see whether the HRRR model capitulates or whether the other data capitulates to it.

Jerry Keeney has today’s featured photo of the day from Smithville Lake.

Depending on the snow conditions there may be a chance for a blog tomorrow.

Joe