The next few days is really going to put a damper on what went down this last weekend. Sunny skies and 50's are out of here and we are turning our gears back to winter.
This also comes just in time for the last week of Meteorological Winter. We'll be dry for Monday and both commutes will be okay. Everything starts late Monday evening as rain will gradually turnover to snow. A Winter Storm Watch is in effect for the entire Stateline beginning tomorrow night in spots. Stephenson, Jo Daviess, Carroll and Whiteside Counties go into effect at 6 p.m. Monday and the rest of the Stateline goes into effect Tuesday morning. This continues through Noon Wednesday.
To put it simply, yes we are going to see accumulating snow on Tuesday and early Wednesday. That's near certain. However, there are still questions as exactly how much will fall. The latest model trends have pointed to a southward movement of the system, which means still accumulating snow but not as hefty. As of Sunday evening, our computer forecast models are giving a big spread in snowfall potential.
On the lower end of the spectrum, the European model is giving Rockford around 3-4" of snow. The NAM and GFS models around 6-8" and our in-house Timecast model going the highest with 8-9". This is a huge spread in snow totals and unfortunately that hinders us meteorologists giving you an exact forecast.
If models were in more of an agreement, yes we'd have higher confidence in our snowfall forecast. However because of this, the snowfall forecast comes with low confidence. As new model runs come in overnight and throughout the day Monday, we'll have a better idea of what's to come in terms of exact numbers. For right now, the forecast models giving between 3-9" is a huge ballpark (NOT A HUMAN-MADE FORECAST).
This just shows that yes accumulating snow is near certain on Tuesday and early Wednesday. This also does mean this is bound to be our biggest snow-maker of the season. We are 8.3" below average for snowfall during Meteorological Winter.
One thing the models in agreement on is the timing of the heaviest snow. Looking at the graphics below, you can see that most of the heavy snow will fall Tuesday mid-day continuing through early Wednesday. This means that commutes from Tuesday morning through Wednesday morning are going to be impacted.
As we go through time, the new model runs will give us a better idea of what will happen. We'll keep an eye on the track and strength of the storm from here-on-out. This will either make our snowfall potential go way up, or slightly down.
Be aware that accumulating snow is near certain for Tuesday and early Wednesday. Because our temperatures have been so warm lately, it won't stick to the ground and pavements initially. Rather the snow will stick to grass first. As our temperatures get below freezing and stay that way late Tuesday and into Wednesday, this is when you can expect snow to accumulate on the pavements.
We'll be tracking this storm around the clock online, on-air and on the 23 Storm Team Mobile App. All in all, be ready for hefty accumulating snow on Tuesday and into early Wednesday and keep an eye on the forecast.