THE LATEST SWEEP....
There have been a lot of numbers out there lately and we're now less than 12 hours out from this event and there's still a lot of variability.
Here's a note from Terry's last post:
Models are not to be taken precisely, they are a guide. Yesterday we had snow to the Minnesota border with two different camps depicting where the heavy snow band would occur.
Today that range is now reduced from 300 miles to 75 or less. Models have converged on a general solution. What you need to know is that if you are on the fringe, maybe just out of the snow band on the models I've shown, you are not yet out of the picture yet. Small track fluctuations are normal at this distance and in a situation like this can change a 1" accumulation to 6 or 7" with a 50 mile bump. Conversely, it could go the other way from 7" to 1". I can't stress enough the sharp cut-off that will be found on the edge of the storm.
Also, if the model says 10" in your area that's not a given. Again, it's a guide that helps us a forecasters determine a reasonable range. Usually, if the track is correct you could expect the final amount to be within 2" of the given number. There is no such thing as exact when it come to forecasting, especially snow. Lots of things can impact the final totals like convective bands, narrow swaths of snow in the primary band where thundersnow dramatically increases amounts in local areas. No way to call that!
Once again these are just models not the gospel truth. I want to lay out the latest data we've gotten in to give you some more information and show you all why there is so much uncertainty.
Here's the 18z European, which is still consistently on the south trend:
The 0z HRRR:
The 0z NAM (which is VERY bullish and has some very high snowfall totals - which are UNLIKELY):
The 0z hi-resolution NAM:
We'll need to wait for the new GFS to come in tonight, but for reference here's the 18z GFS:
It's going to be a matter of MILES - a sharp cutoff will exist from a lot of snow to little to no snow.
We're going to continue to watch this system. There has been uncertainty the whole time and as we're getting close to game time the picture isn't crystal clear. If you're in Iowa, Illinois, Missouri and Wisconsin you'll want to pay close attention and be prepared for strong winds and low visibility through the day Sunday.
More updates to come...