Good morning Kansas City,
We are likely about to experience a once in a lifetime May snowstorm. Parts of the KC viewing area will likely have accumulations of snow as a storm intensifies and moves our way. Last night, on 41 Action News, I showed a special weather graphic that began with this first page, below, and I then showed all of the potential scenarios ranging from just wet with rain and a few snowflakes, to a more likely 2″ to 6″ snow range in a small band that may very well end up near Kansas City:
Let’s discuss the weather below, but I will begin with one of the questions: How low will the temperatures get tonight. If it doesn’t drop below 35° most of the snow would likely melt and not accumulate. We are forecasting a low of 32° or 33° tonight:
A strong cold front came through Wednesday evening and we are currently having another, and hopefully last cold blast of the season. So, we have the cold air, and we also now have a developing storm system aloft that is just now beginning to form.
- How strong will this storm become, and where will it track?
- How low will the surface temperatures reach overnight?
Let’s take a look at this developing storm and answer these questions, beginning with the 7 AM surface map:
It is currently snowing in the Texas Panhandle where it was 97° on Tuesday. NINETYSEVEN DEGREES Tuesday and it is now snowing and accumulating. Wow! Our temperatures are dropping, but again how low will they get overnight when our best chance of snow arrives?
The storm system that is going to create the conditions favorable for snow is just now deepening, strengthening, and digging into Kansas. This storm, as you can see on the left (click on the map for a larger view) is just sagging south today as the energy bumps into a strong blocking pattern over the eastern part of North America. You can see the block over the east. Just east of the block is an upper low off the New England coast that is also just stuck there with no where to go. As this energy gets blocked we have this unique set up that will likely not happen again in our lifetime.
By Friday morning the upper low is forecast to completely close off and something quite fascinating begins happening that will likely impact our potential snowfall accumulation. Kansas City may very well go into southeast flow aloft as you can see to the right. What does this mean and how would this impact us?
The bands of rain and snow that will be seemingly moving off to the east later tonight may very well stop and begin moving back to the west. There will be a pivot point where the band of snow/rain just stops and then just sits there for a while and this location will likely end up with the most snowfall.
As this storm system closes off it will begin pulling warmer air around the system. Take a look at the 850 mb level, around 5,000 feet up in the atmosphere:
The solid purple line is the 0° isotherm. Isotherm means a line of constant temperature, so it is 32°F all along that line. Notice how the warmer air over eastern Missouri (the 3°C and 6°C lines) is being pulled west towards Kansas City. Eventually this warmer air will wrap around the entire system. How long will it stay cold enough to snow before it changes to back to rain? There will likely be a shrinking area of snow with a change back to rain as we move through Friday.
We will be under the influence of this storm through Saturday and then hopefully this storm will exit the area Sunday as the blocking pattern breaks down.
The latest NAM model forecasts a temperature drop to 32 or 33 this evening with heavy snow. We will monitor these developments closely. What do you think bloggers? Can you believe this?
Have a great morning. We will update the blog later this afternoon.