At 9:06PM... on Wednesday night... I considered dropping my snowfall forecast in Topeka. The original range was 3 to 5 inches. I was now considering 0 to 1 inch! By 9:20PM... I decided to stay with the original 3 to 5 inches. That's a big difference. Frankly... as of 11:30PM... when I am writing this... I have my fingers crossed that my decision was correct. One of the hardest things we do is forecast snow amounts... and this is no exception to that rule.
Let me show you why I considered dropping it... and why I am confident now that I made the right decision to stay with the 3 to 5 inch forecast for Topeka.
First... this is from the "NAM" forecast model... and shows the expected precipitation for Midnight on Wednesday night. This image hit my computer at 8PM on Wednesday night. Notice that there is absolutely no precipitation in Kansas... or northern Oklahoma. Concern... begins right here. This is the last computer model that I was to get before the 10PM Newscast.
Continuation of that computer model. This is the projection for 6AM on Thursday morning. According to my running forecast... there should be snow at this point. Yikes. I am now wide eyed and... fearful of grocery shopping for the next 2 weeks. :)
The next image... below... shows Noon for Thursday. Now I am having a vision of a call from my boss... asking... "where is the snow". And I seriously considered dropping the snow forecast at this point.
And... the final image of this series... shows the storm has now missed Topeka completely. It now appeared to be possible that instead of 3 to 5 inches... Topeka could see absolutely zero snow! Not a flake.
<h3>ESP Radar At 10:00PM</h3>
So... question #1 is... does the first part of the computer model match up to the ongoing trend? No. It didn't. First of all... it had the central area of low pressure to far south... and thus takes the precipitation farther south than likely. Next... check out the radar. There is already precipitation in south central Kansas and northern Oklahoma. The precip there was "light" at this time... but it was clear that this precip band was expanding... and moving northeast... following an evident jet stream. This followed a previous computer model solution.
<h3>New Computer Model after 10:00PM</h3>
GFS computer model has done a better job on the last few snowfalls to hit the area. Check out the first slide... and how well it matches the ongoing precipitation in Oklahoma and Kansas. This is for Midnight Wednesday night.
GFS continues to push snow northeast toward our region by 6AM.
GFS solution for Noon Thursday below. The third darkest shade of green covers Topeka for this time period. This is about 1 inch of snow in the middle of the day. The yellow and orange are higher amounts. 2 or 3 inches during the middle of the day.
GFS solution for 6PM Thursday below. Still snowing across the entire area.
Note: No computer projection shows significant snowfall in the Concordia area. Areas northwest of Topeka will see lesser snowfall. Areas to the south and east of Topeka are likely to see more.
After all of the map reading and number crunching... weather has a way of keeping us humble. I have done the best I could to forecast this one accurately... as we always do... but nature is nature. Computers and humans will never be perfect. :)