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Weather Blog - 100% Chance Of Snow Tonight

Posted at 7:09 AM, Jan 23, 2020
and last updated 2020-01-23 14:31:29-05

Good morning bloggers,

A storm system will be developing right overhead today. This snow forecast is another tough one for Kansas City. Forecasting snow only becomes difficult when we are asked to forecast the exact amount that may fall. I am 100% confident that it will snow tonight. And, our weather team at 41 Action News will be 100% accurate on this prediction. Now, what is it that you would like to know? I am guessing one of your first questions is "how much snow will fall in my neighborhood?". And, then other questions, as to the timing of when it will begin and end. Will there be school closings on Friday? When forecasting rain, I could tell you that it will rain and there is a 100% chance. And, then when it rains we are right! If we had to get the exact amount of rain predicted for each location, we would not be nearly as accurate. For example, if we forecast 1/2" of rain will fall, and if you are in the heavier thunderstorms, then you may have 2" of rain. And, then let's say only 1/4" of rain falls, then most of you would consider that an accurate forecast. If this same forecast were for snow, we would be predicting 5" of snow to 20" of snow. And, then when only 2.5" of snow falls, you would consider our forecast so wrong. Right? Well, this is what is asked of us, and we do a very good job at it. In the last big storm around two weeks ago, we predicted 3" to 6" of snow and 2" to 5" fell, and many people said we did not get it right. I will argue we did get it right. Well, anyway, let me present the facts on this storm that is approaching.

I showed this forecast graphic on the air last night. This shows that I am 70% confident that we will have at least 1" of snow, and that 1-2 inches or 2-3 inches of snow will be the most likely amount by the time we get up Friday morning. There is still a chance that this storm will really come together and produce 4" or more. For this to happen it would have to get very organized by midnight tonight.

I also showed this last night, and it is still about the same this morning. By this evening, a storm will be intensifying over eastern Kansas and western Missouri. Take a look at the raw data analyzed on this map:

This map shows the storm intensifying aloft. This is the 500 mb level, or half way up in the atmosphere in weight. The top of the atmosphere has no weight and thus a pressure of 0 mb (milibars). And, the surface has a pressure of near 1000 mb. So, the 500 mb level is half way up, and around 18,000 feet above us. We look at this level of the atmosphere to find the storm systems, and this one is intensifying due south of KC. This places us in easterly flow aloft, and this means that the snow developing should be moving from east to west. Watch my weather forecat tonight at 10 PM on 41 Action News, and I am expecting to be able to clearly show the snow beginning to move from east to west. We will see if this indeed does happen. If it does, then the snow will begin accumulating and lasting into Friday morning. Here is the midnight forecast map:

Notice how the temperatures are dropping to 32 degrees by around 10 PM to midnight. This is when the snow should begin accumulating more efficiently. If it starts earlier, then the higher amounts are possible. If the temperatures do not drop as fast, then 1" or less is possible.

Kansas City Weather Timeline:

  • Now -5 PM: Drizzle or light rain, possibly mixed with snow. No accumulation expected. High: 38°
  • 5 PM - 9 PM: There is a 100% chance of drizzle or rain changing to light snow. Some accumulation is possible, likely less than 1". Temperature dropping to 33° The wind will begin increasing from the north at 10 - 15 mph.
  • 10 PM - 6 AM Friday: There is a 100% chance of snow, possibly heavy at times. Accumulations of 1" to 3" expected with slick and hazardous conditions. Temperatures will drop to 29° with north winds up to 18 mph..
  • Friday: Snow ending with temperatures staying below freezing. There will be slick and hazardous conditions. High: 32°

So, will there be school closings on Friday? The kids, parents, and teachers want to know. I would say there will be a lot of them, but will yours be closed? I better not get into that prediction. Have a great day. We hope to see you at Kansas City Royals Fanfest this weekend. We will be there manning our booth. I am planning on being there Saturday afternoon around 2 PM with Sunny, and I may even bring Rainbow The Weather Puppy.

Have a great day! We will go in-depth and bring you KC's most accurate forecast!

Gary