New high-resolution model data coming in aggressive on snow totals for Tuesday
We are now about 36 hours from the start of this event and 48-54 hours away from the end of it. Good news is, we now have all of our model power at our disposal. First, let me explain what 'high-resolution model data' is. These models, namely the GRAF, HRRR, and NAM, are high-resolution, which means they're better at seeing finer details such as precipitation rates and areas of higher snow bands. Global models are decent in the long range, but they have lower resolution, meaning they're not as good at seeing these details. Global models give us a broad view, while the high-resolution models put things into better focus.
These models have more short-term data, with the GRAF only running 72 hours out, the HRRR 48 hours out, and the NAM 72 hours out. We are close enough to the event to now analyze these.
So, now to the notable part. All of these models are currently coming in more aggressive than the global models, especially the GRAF and HRRR, which just came out tonight. The GRAF continues to show the possibility of 8-12 inches of snow across the area. While it may be overdoing things, it has been remarkably consistent. It can also tell us the location of where the heaviest precipitation will be. We call this "banding" in the snow world. It has the heaviest band of snow setting up right across I-10.
The new HRRR model shows anywhere from 7-9 inches of snow across the area through Tuesday night, also exceeding global models. More importantly, it agrees with the GRAF in terms of the location of the heaviest snow totals, which it's showing right along I-10 communities.
For this reason, my forecast will show lesser snow totals towards central Louisiana and possibly the immediate coast, but a higher band of snow totals right along I-10. Average snow totals across the area will be in the 3-6 inch range, but within this I-10 band, snow totals of 4-8 inches will be common with amounts as high as 8-10 inches.
Behind the snow, hard freezes will continue. Lows could be in the mid-teens Wednesday morning, after not getting above freezing at all the Tuesday afternoon before. It's debatable if we get above freezing Wednesday afternoon either. Another hard freeze is likely Thursday morning. Protect those exposed pipes with this Arctic outbreak for sure. I'd recommend not letting faucets drip as this could lower water pressure in communities, creating a secondary hazard for customers and firefighters. Be careful warming your home with space heaters!