This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Well today it feels like winter… and with all the clouds around, and a cold start, it’s going to really struggle for us to warm up to around 30° or so. This may be the 1st sub-freezing day (for highs) that we’ve seen. Unusually late into the season. This will tie us for the 5th latest (1946) IF we don’t get to 32°.

Meanwhile northern MO may have some light snow or flurries today…perhaps coating the ground. Our KC eyes are on what’s coming later on into the start of 2022 as an arctic front will be moving through the area early Friday evening…and that will do it for another brief warm-up coming over the next 48 hours. A blast of arctic air, wind, sleet and snow is on the way.

Some may need to shovel… others more so.

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

Forecast:

Today: Cloudy and cold. Highs only around 32°. There may be a few flurries out there

Tonight: Cloudy with steady temperatures in the mid 20s

Tomorrow: More sunshine, during the afternoon with highs in the mid 40s

Friday: Milder with highs in the 50s… there may be some areas of lighter rains/drizzle that develop after sunset. Perhaps some freezing drizzle towards 12AM.

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

Discussion:

We continue to experience a volatile weather pattern around the country. FEET of snow in the western US…severe weather in the south…record breaking warmth today in the deep south and for KC…at least for the next 48 hours…sort of a lull in between systems.

Today severe weather will develop in the deep south…including the risk of tornadoes.

That’s an enhanced area of severe weather (a level 3 out of 5) in a part of the country that does get severe weather in December. That enhanced area represents the highest risk of tornadoes as well.

One of the things that is sort of getting lost in all the warmth is that the dew points in the south are wayyy high. 70° dew points in the deep south in late December are pretty impressive and that is helping the set-up developing across MS/AL/TN.

While that occurs…record highs will be attainable in these cities in the deep south.

So the heat is there…the moisture is there…there is the front that came across our area yesterday…that’s there today…and you have some jet stream dynamics to help as well.

In northern MO…there is a the potential of some light snow or flurries. The atmosphere is pretty dry overall…and it may take awhile to saturate…but at least a coating is possible across northern MO north of the 36 highway corridor towards the IA border.

That’s today!

As far as we go over the weekend…things are progressing according to plan. The arctic front is #1.

  1. The front. This will arrive sometime Friday evening. We should warm-up into the 50s ahead of the front and start tanking behind the front on stronger north winds of 15-25 MPH or so. Take a look at how things may roughly progress from 6PM Friday…to 12AM Saturday (Happy New Year) to 6AM Saturday.
3PM Friday
12AM Satuday
6AM Saturday

I won’t be surprised if we’re a bit colder than that as well… typically the models can’t catch up to the rapid temperature drop with the arctic air moving in so quickly.

That’s at the surface…now let’s zoom in to KC and show you one of the big issues with whether or not we have a lot of sleet or snow… and that’s what’s happening above the surface, around 5,000 feet. Remember to get snow, we need to have the entire atmosphere above us to be below 32°…notice at this particular level the 0° line = 32°F.

3AM Saturday—despite surface temps below 32°…aloft is above 32°. This supports freezing rain/sleet for KC proper
6AM Saturday: Still fighting the transition along the I-35 corridor and eastwards. Snow west and north of I-35
9AM Saturday: All the the Metro is in the snow…mixed precip south and east of KC

These maps are from the EURO model. The GFS is running about 5°C colder…which is substantial really. That transitions everything to snow quicker…and hence you get more snow off the model. For example just looking at the 3AM temperatures at 5,000 feet….compare it the the EURO one above…

So about 30-40 miles further south with the 32° line at that level at least. This would mean a faster switch from freezing rain to sleet to all snow in KC.

It’s really tough at this point to quibble about either solution because both are plausible really.

At this point I really like looking at the ensemble outputs…and while not perfect when handling how much snow is forecast when we have these mixed bag of precip types to deal with…and since the ratios use a strict 10:1 ratio…1″ of rain=10″ of snow…these aren’t perfect…but I like to see what they’re showing.

In my head I look for how many of the ensemble members are showing at least 1″ of snow…how many show at least 3″ of snow…and then at least 6″ of snow. We get these members from the EURO/GFS/Canadian models…here are EURO and the GFS members. You then can average all the members and get the mean.

The problem with this approach as well is that it tends to flatten out extreme events. Ensemble members are essentially the same model except they are run with different initializations and tweaks. By their very nature and outputs you’re going to get different results and outputs.

So let’s start with the EURO ensembles…

Most of the members…51(!) are below 1″ for KCI

Now the GFS…

Most of it’s members (31) are over 2″…but 12 are below 2″. There are some BIG numbers in there!

Now the Canadian…

Only 3 of it’s members are under 2″. 18 are over 2″

So clearly we have a discrepancy with how much snow falls up at KCI at least.

Most of this has to do with the timing of the switchover to accumulating snow…and the strength of other various features.

As I mentioned there is a pathway for each model to have a better solution. IF the EURO is right and we’re waiting on snow after daybreak…we may only get up to 2″. IF the other models are right with a faster switch…then yes a 3-6″ snow can be on the table, especially north and west of I-35.

Areas farther to the SE of the Metro should have more sleet than snow it appears…with significantly less snow totals.

The morning run of the NAM model just came out as I was typing this…

It sort of leans more towards a EURO solution with a more extended period of mixed precipitation overnight with a switch towards some lighter snows near daybreak Saturday. It is VERY similar to the EURO model in terms of the 32° line at 5,000 feet at least at 6AM Saturday.

The transition to snow is close to the I-35 corridor at 6AM

Let’s say we wait that long to get accumulating snows to start…then how much moisture do we get from 6AM to 6PM…

About 1/10″ for most of the Metro…a bit more near and north of KC…this would roughly be a 1-3+” snow system for accumulations in KC…with closer to coating to 2″ on the SE side of the Metro and 1-3″ on the northwest side of the Metro…i.e. Leavenworth to KCI to Kearney.

So that is where my mind is right now.

We’ll need to watch the 32° line aloft and see IF things progress quicker because that would ramp up the snow totals by a couple of inches at least…

Regardless of all this…I still have considerable worries about a flash freeze as I’ve stated for the last couple of days early Saturday morning…

Things will be changing but what won’t change is the coming 2 day cold shot. Assuming we don’t have a lot of snow on the ground…we should warm up pretty quickly early next week. Another cold shot comes at the end of the next week.

Also of note…temperatures Sunday AM may tank to near 0° and perhaps down to -10° in northern MO!

OK that will do it today…see you tonight with more updates.

Joe