I am writing this post in advance of much of the 18z modeling data that will come out over the next 2 hours, which is why I am not quite yet forecasting widespread snow days for Southwestern Connecticut on post-Super Bowl Monday, but recent trends have me thinking that at the next update to come around 5:30 PM (the final pre-Super Bowl update) I will be forecasting snow days, so make sure to check back in before the big game to see whether everything is coming together to lead to schools closing. This post is going to focus just on some more recent trends regarding the storm tomorrow, with all talk of the two other storms being pushed to later blogs.
The biggest trend noticed over the past few hours since the last update was one towards more moisture from the later 12z weather models that came out. The 12z ECMWF weather model showed widespread amounts of 4-6 inches across the area with a shift north in the storm. One of the other main international models, the 12z CMC, also seemed to show a shift, though it was not as drastic as the ECMWF. The third main international model I use, the UKMET, did not show much of a shift. My takeaway from all of this, though, is increased confidence in my forecast of 2-4 inches of snow for all of Southwestern Connecticut with maybe isolated areas near 5 inches at the coast, and increased confidence in schools needing to close. The National Weather Service has updated their grids to expect generally 3-5 inches across the area, very close to my thinking, and as a result they will be issuing Winter Weather Advisories later today. The publicity that those will get can sometimes be enough to close schools, because this is 2-4/3-5 inches of snow coming at just the wrong time for schools.
That is mainly why I upped the snowfall amount with this forecast: no major timing changes but some weather models have trended towards more moisture. I could go in depth about why I don’t exactly buy the extreme ECMWF solution here, but I’ll spare the details. Basically, the model has not performing well this Winter, especially in the short term, and I will trust the GFS and other weather modeling that has had a better grasp on smaller scale systems like the one moving through tomorrow. Still, there is that upside potential, 20-30%, that we get widespread amounts of 5 inches or more, and so there is a chance the forecast may need to be revised up, which would almost guarantee snow days tomorrow. The only reason schools would be able to open is because temperatures at the surface are near freezing, so if roads are properly treated they could be ok in the first hour or two of snow, but snow could be moderate to heavy for a period and it will be sticking and coating roadways too as temperatures, though close to freezing, will still be below. Driving conditions will be treacherous for most of the day and at this time confidence is only growing that school closures would be the correct call.
I’ll have another pre-Super Bowl update with all the 18z weather modeling data as well as current trends with the storm, etc. around 5:30. Make sure to check back then and see if a snow day has been forecasted yet. Until then, as always, constant updates will ensue on Twitter breaking down each of the weather models and any trends that I see with the current storm, and coverage will continue through the evening and into the overnight hours on the potential of this storm to cause travel troubles and close schools.