A winter storm is going to be the first highlight of 2022 in Kansas City as a combination of disturbances out west affect the Plains starting Saturday morning. The good news is that Friday night parties etc. are going to be fine.

The arctic air will be moving in during the evening, and while the temperatures will be dropping quickly later on, we should see OK road conditions into the 12AM hour… if not beyond.

The changes in the data (so far… more are coming) is a slow down in the timing of the worst of the weather, and also an uptick in the snow amounts for part of the area as well. This is going to be a very tricky snow forecast in terms of totals because of the sleet transition timing… and what part of the area receives the heaviest precipitation.

It’s not out of the question that the worst of this comes more towards later Saturday morning into the late afternoon, and because of the way the storm is structured, it may be the “storm that keeps on giving” because the snow may last (probably light) well into the evening as well.

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Forecast:

Today: Fighting lots of clouds into the afternoon with chilly but seasonable conditions. Highs in the upper 30s to lower 40s. Cooler northeast and a bit milder SW of the Metro.

Tonight: Fair skies with somewhat steady temperatures near 30°

Tomorrow: Partly cloudy… breezy and milder with highs in the mid 50s

Tomorrow night: Fine through 12AM perhaps a bit later…then some light and patchy areas of freezing rain showers develop. These could lead to a light glazing on the roads before daybreak where the ice accumulates…especially on bridges and overpasses. Temperatures will be tanking. Whatever we are at 12AM…25-30° or so…will be the high for the day. By daybreak we’re closer to 20° as we transition more to sleet.

Saturday: Sleet switches to snow, heavier snows possible, especially from Downtown northwards. The I-35 corridor area may define the heavier snow areas or at least close to it. More glazing and sleet towards the SE of KC, more snow towards the NW of KC. Falling temperatures to near 10° later in the day. Wind chills near 10 or 15 BELOW later in the day with gusty north winds to 25+ MPH

Sunday: Sunny but cold. Lows in the morning near 0° (colder with deeper snows) and highs in the afternoon near 20°. Lighter winds.

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Discussion:

Let’s start with the winter storm watch that has been hoisted for the entire region.

That’s all 2.6 Million people in the Pleasant Hill area and all 650,000 people in the Topeka NWS area of responsibility

These watches in time will be extended towards the northeast into Chicago…Milwaukee and into Michigan as well.

For us locally, these watches are in effect starting early Saturday morning.

There have been some subtle changes in the data and more changes are coming over the next 36 hours into the morning of the event…

  1. The system that we’re tracking. There are two really, and as I mentioned earlier in the week, the pirouette of how these systems interact with each other will be a big factor in what happens locally. The two dips in the flow up around 18,000 feet or so are circled.

The dip off of SW CA…has been creating heavy rains in southern California Thursday, and even the potential of some waterspouts near the coast as well. The two things will eject into this by Saturday morning. The system off CA weakens as it comes this way…but it should be the trigger to get more precipitation going as it comes into the arctic air that is flowing in.

That first little wave will help to moisten the atmosphere and provide the left needed to get winter weather going in the area. The second wave will provide the extra lift in the afternoon and evening to help give the snow an extra punch leading to the risk of snow into the night for awhile at least.

2) One issue that we’re having though is that while the arctic cold is flowing into the area later Friday night and Saturday, the air above us will be cooling down at a slower rate. As a matter of fact, the atmosphere may not be conducive for full-on snow through sunrise in KC proper. For areas NW of the Metro, this will be a faster evolution. For areas SE of KC…a MUCH slower evolution and that brings the sleet issue front and center. Sleet is going to be an issue in the area for awhile in the morning.

Let me show you the way the atmosphere may be setting up at daybreak Saturday (6AM). To do that I want to show you a forecast sounding off the morning run of the NAM model and as you look at it remember what happens close to the ground is only a small part of the atmosphere…

6AM Saturday

This is a forecast sounding. The RED line that stair steps up through the atmosphere is the temperature. The GREEN line is the dew point. Where the lines are on top of each other…indicates where both are the same value…hence the air is totally saturated. Where they spread apart more and more…drier air. The slanted highlighted thicker light blue line is the freezing line…as you go up through the atmosphere.

I’ve circled an area…about 5-10,000 feet above the ground that is to the right of the thicker light blue line. That represents the model seeing a layer of 32°+ air…that is a big problem. Snow that is above that layer…will melt…then as it drops through the arctic air closer to the ground…it will freeze into ice pellets (sleet) or perhaps a mix of freezing rain and ice pellets

Notice that layer is still there at 9AM…

9AM Saturday

This again is more or less a sleet look, and this is for the KCI area… that “warm” layer (above 32°) may be even thicker on the south side of the Metro.

The longer we’re fighting sleet the over all lower the snow amounts will be.

This is just one model…last night’s run was snow crazy locally. This run isn’t. It’s the reason why I didn’t want to knee jerk the forecast around last night.

Last nights update

So let me show you the difference in the snow forecast off the NAM model. This is a 10:1 ratio…which sort of is OK…but there needs to be some fudging here too.

Comparing NAM runs…slide right for today’s run…left for last night’s run

Big difference right?

What most of the data has consistently shown is that there is going to be a sharper cutoff to the significant snow…and this cutoff could be as close to us as KCI…or the I-35 corridor. Areas S/SE of there much less snow and areas to the NW of that line…more snow.

I’m still sort of in this 1-4″ range forecast from the SE of the Downtown area…towards southern JOCO and JACO…to the higher amounts near and north of KCI towards Weston. There is upside…especially NW of the I-35 corridor. Areas towards and north of 36 highway still appear to be in somewhat better shape for heavier snows because of less sleet.

Again this may come down to more of what’s happening at 5,000-7,000 feet above us than what’s happening here at the ground in regards to temperatures.

Is this totally right? Maybe not. It’s just one solution of many coming. I have a feeling that it might be underplaying the backside of the system. In other words it slams us fast and furious with sleet and ice…some snow…and things wind down so quickly after lunch.

So we really don’t have the chance of getting more snow because the 2nd system coming up isn’t being modeled correctly. That 2nd system will continue to send up little waves that could provide more “lift” into a bitter cold air mass. That gets snow going (again the “storm that keeps on giving” thought. At least I think that may be happening.

The other issue is that “warm” layer may be real. This is a wave coming up from the SW…and born in the sub-tropics so there is “mild” weather aloft connected to it…so I do feel that the sleet thing is a “thing”. The issue is can the 2nd system behind this provide additional lift into a colder atmosphere to get the snow going enough to get some better accumulations. If not…we’re likely going to fall into the lower end of things in terms of accumulations.

3) Can the track of the heaviest snow change? Yup…for sure. IF we can get things to come 50+ miles farther south…in other words IF this disturbance (circled) is south of where the model thinks it’s going…that would wipe out the “warm” layer faster and we can get more snow.

Don’t be surprised though IF there is little to no actual snow on the ground Saturday morning.

4) Are there more twists and turns ahead? Yes for sure I think…it’s the reason why forecasting snow is so difficult. Add in the sleet component and or the freezing rain thing…and it’s complicated.

5) What am I most confident in? The cold obviously…that’s set in stone

6) What am I least confident in? The snow totals…especially SE of the I-35 corridor areas. There is big bust potential I think…it could easily be a coating to 1″ type thing on the south side of KC Metro if we don’t get properly positioned. Also some of those higher end totals for northern MO too…there may be some room down for those numbers.

Finally…and to reiterate. These numbers will likely change over the coming 36 hours. There may be some abrupt changes to things on Friday too. I’ll stick with my 1-4″ thoughts from SE to NW through the Metro though.

OK that’s it for today.

Joe