More snow expected after mid week warm-up

TAP HERE FOR THE LATEST STORY ABOUT THIS WEEKEND’S SNOW FORECAST.

COLUMBUS (WCMH) – The weather is changing, with some major swings coming our way this week.  We look to see a temperature swing to as warm as 20 degrees or more above normal later this week, before a potentially big weather system slides into the area to start the weekend.

A very cold pattern finally ended

Monday was our first above normal day for an average temperature since December 23rd.  In fact, during that 15-day, or half month long losing streak, our average temperature was 17 degrees below normal!!  We have already dropped below zero 4 times this month as well, something we haven’t done in a while.

The good news is, we are going to see a very big swing upward in temperatures this week, with above normal temperatures experienced on Tuesday, in the mid/upper 40s on Wednesday, and mid/upper 50s on Thursday.  This will all mean a big melt in our snowpack, with much of it melting away before the end of the week.

After the warm-up, payback will arrive late in the week

So first we will watch warmer air moving northbound that will bring back the chances of precipitation starting early on Wednesday.  With ground temperatures a degree off of freezing as the start of the precipitation, and warmer air moving in aloft, it is possible that we could see a very narrow window of freezing drizzle Wednesday morning.  But this window should be very brief as warmer air will return and change to all rain showers through the day.

Temperatures will soar into the 40s during the rain, and will accelerate into the 50s on Thursday with additional rain.  Friday though, we will have an early day cold front pushing through, this will allow colder air to spill down as a disturbance arrives later in the day on Friday bringing additional moisture.

Here is where the uncertainty comes in… how much snow we are going to get

One of the things that needs to be stressed is that a long range forecast model is not always correct.  Also, winter weather forecasts for snowfall depend on many factors, and a slight increase/decrease in position, intensity, or temperature could change a lot in a snowfall forecast.

To show this point, below is the same American GFS model from 3 different forecast runs today, 6z, 12z, 18z  (1a, 7a, 1p)

The above 6z run did a horrible job of snowfall that we saw last night into today, with numbers roughly an inch higher in Columbus, to 2-4″ higher to the east.  This means that additional snowfall still of almost a foot on Friday/Saturday and snow showers for Sunday.

6 hours later, the above model cleaned up that bad data, and gave a forecast for snowfall Friday/Saturday/Sunday only.  Still notice the numbers are high, especially from the I-71 corridor and west.

But the latest model that was run this afternoon, greatly reduces the previous model runs from today, and lower the snowfall numbers for the upcoming weekend.  This is still a significant amount of snowfall, and would represent roughly 67% of the total snowfall from last winter in one weekend event.

So what should we expect heading into this weekend?

Well it depends on what long range forecast model you want to look at.  It also depends on what run of that model you look at.

Right now, it appears the models are coming into a bit better agreement on position of this system heading into the weekend.

Below is the most likely forecast track heading into the weekend.  Notice the warmer more rainy air near the track and heaviest snow to the west in Indiana and western/northwestern Ohio.

Below is a more westerly track, which is more possible of a shift if there will be a shift on this track.  This would mean the heaviest snow band would be more to the west as well, and our snow would be more mixed with rain, therefore snowfall numbers would be lower for us.

Finally, I show below a shift of the track to the east, and what this could mean for us.  This would be the lowest potential of happening, but not a zero chance thing either.  This would bring in additional snowfall and give us our potentially highest snowfall numbers heading into the weekend.

 

Below is a “most likely” snowfall forecast for Columbus as of tonight for this upcoming Friday through Sunday.  We should have higher numbers north, and lower numbers southeast.

As far as forecast for our entire area, below is what I am looking at.  This graphic will most likely have some tweaks and minor shifts needed as the system becomes more defined.

Bottom line…. a lot can change between now and the end of the week.  Besides our big warm-up, the potential for this winter weather system will be something we will watch very closely and update the forecast for all week long.  If you see crazy graphics someone is sharing somewhere online, remember, they are sharing one run of one model, and on one day.  As you can see above, just relying on one model can have many different outcomes during one day of calculations.

I do expect colder weather, a messy forecast by late Friday, and at some snow to start the weekend before a much colder airmass returns to our area.

Stay tuned!

Remember, if you ever have great pictures, want to share a weather story, or have a question about the weather, email me, dmazza@wcmh.com

-Dave

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