First chance of snow coming into the metro

As we head into the last day of November tomorrow, Mother Nature may give us one last day of November snow, and perhaps it could be more than just a casual amount for parts of the area.

Snow is expected to develop before dawn tomorrow, and my concern is that a band or two of snow could overcome and give someone out there a decent accumulation (over 2″ worth).

These first snows, for whatever reason, are a bit tricky. Roads can get slippery where the heavier snow falls, and while the weight may be more east of the metro, I still have my concerns about how this really plays out in Kansas City. But why?

Because things will develop at the top or near the KC area. So if something comes along towards dawn or towards our west, it might be a bit more problematic in terms of how much we get.

After tomorrow morning the snow will pull away and the colder air will settle in for a few more days before we moderate a bit towards the middle of next week.

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++ ++++++++

Forecast:

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

Tonight: Clouds lower and thicker. There is a chance of light snow towards dawn. Lows in the mid to upper 20s

Tomorrow: Snow is possible in the morning. Dust accumulations to 1″ for most of the metro, with higher totals toward central Missouri of 1-4″ possible in some bands

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

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++ ++++++++

Discussion:

There is still a big discrepancy in the models as they try to figure out how the bands of snow that should develop towards dawn assemble and how strong they are.

I don’t have a good feeling about this and I’m worried that it might be more of a major snow in the metro than what I’m currently predicting. Or at least there’s an upside that shows I’m not trying to sweep it under the rug.

My concerns are partly because I see a strange spring-like setup in the models just above the surface. It’s a low level jet stream hitting us tomorrow morning. IF this was spring, it would be the lineup for thunderstorms. This setup tonight and tomorrow is kind of maximized towards dawn on top of the KC area on some of the model data this morning.

IF this was spring or even summer, we’d be worried about thunderstorms developing on top of or near the metro before dawn. But since the air is so much colder, the focus will be on potential bands of snow to develop.

Where these bands of snow actually form is usually the battle because there is the potential for some higher than totals (over 3″). But where they are not actually formed, the amounts can be significantly lower or none at all.

I can see the models struggling with this in their output this morning. That’s what makes me nervous. I fear there is something bigger going on out there than what is being talked about.

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

Note the sharp cutoff near the I-70 corridor. That would be a BIG problem and a 4-8″ snow for areas just northeast of the metro. Even the north side of KC is in about a 2-4″ swath with showers on the south side.

GFS has something similar, but not to that degree. Again, it’s trying to see these banded snows (which these models aren’t very good at).

The Canadian…

Again, trying to see these bands.

And overnight in EURO…

It is important to note that the GFS ensembles, which are a mix of about 30 models with different results, have lower totals in the metro with higher totals towards central Missouri.

This was pretty much my forecast last night with 1-4″ potential towards central Missouri and east, and lighter totals in the metro.

The morning run with the HRRR model really gave us nothing. Maybe some showers. The HRRR model would typically do better with this, and part of the reason is that it shunts the wind above us more west to east more quickly.

Take a look at the comparison of two models. The morning run of the NAM model and the HRRR model. This is for the wind field around 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 where the wind blows. This is until 6 Saturday.

That difference is the problem, I think.

That’s the key to showers or 4+” of snow in the metro.

Another complicator to this is that it really isn’t an organized storm coming up. It’s basically a series of weak disturbances broken up into pieces that aren’t a confidence builder for big totals.

There is also a lot of dry air ahead of these features that needs to be overcome in the first place. So IF the forcing or lift is weak in places, the dry air will be a bigger factor in chewing away at the falling flakes. But because a number of disturbances are coming through to perhaps locally improve these lift areas, I think the dry air can be overcome.

In a way, and maybe to bring this home, I think of a cup of marbles and then flip that cup on top of a table, all those marbles going in different directions and at different speeds. In front of each marble there is “lift” in the atmosphere, and behind each marble the air sinks.

In the weather world, we know that the orbs are going to travel from west-northwest to east-southeast. So that helps a bit, but we don’t know how many bullets there are or where exactly they’re going. We have a broad idea but not a precise idea and that is also a problem.

Oh, and there might be some larger orbs in there compared to smaller orbs that affect things differently in the atmosphere.

So you can see how things can go off the rails…

So what do I think right now? I think NAM is too aggressive with its snow production. I may increase the metro snowfall from a dusting to 2″ or so (up from 1″) in the late shows tonight and before then I will have the final model runs to hopefully confirm, or not, that thought process.

I still think there could be some 2-4″ totals towards central Missouri. Again, Mizzou fans, be aware of that tomorrow morning if you plan on making that trip. Alex will have that info for you.

I think the other model runs have a chance to be more accurate in this case…

I’m bothered by the HRRR model and a few others give us next to nothing. Again, I can see why they are so negative about snow here, and they could end up correct, but I won’t let my guard down at this point.

I’ll get a video update out around 18.15 fox4kc.com and another late night update around 23.00 on the website. We have basketball and football tonight, so no early newscasts and our late news is delayed 30-45 minutes to somewhere in the 10:30-11pm range. So that’s a good thing and a bad thing. I’ll be curious to see if we see the HRRR model capitulate or if the other data capitulates to it.

Jerry Keeney has today’s feature photo from Smithville Lake.

There is potential for a blog tomorrow depending on the snow situation.

Joe