11AM Update – Blizzard Inches Closer to NJ: Heavy Snow North, Mix South
The combination of heavy snow, high winds, low visibility, and coastal flooding will make this nor'easter a nasty storm, no matter where in New Jersey you are.
I really had not planned to craft a midday forecast update. But as I'm studying the 06Z and 12Z model runs, I'm seeing a clear warming trend at the 850mb level. That's about a mile up into the atmosphere, and a very important part of the sky for snow development.
So as temperatures at 850mb (and probably at the surface too) climb above-freezing for a bit, any snowflakes will melt and fall as rain instead. Therefore, I believe we are going to see more rain/mix and less snow across southern New Jersey than I had previously anticipated. I had always figured that rain would be the dominant precipitation type along the southern coast. But further inland, even a brief period of rain and/or sleet mixing with snow could significant decrease snow totals.
I realize my new "4 to 12 inch" contour for coastal and southern New Jersey represents a wide range. But that's necessary, given the forecast's inevitable uncertainty. There is going to be a sharp cutoff between "lots of snow" and "hardly any snow" — precisely where that sets up is still anyone's guess.
Meanwhile, the rest of our nor'easter forecast remains the same — heavy snow to the north and west, wind, surge, and waves. A Blizzard Warning, Winter Storm Warning, High Wind Warning, and Coastal Flood Warning go into effect late Monday and Tuesday.
By the way, if you've been following my weather blog posts all weekend, this was almost precisely Scenario #2: The Coast Hugger.
I'm not a fan of "flip-flopping" from forecast to forecast. But I'd rather correct an error in judgment now, rather than wait until later (or remain stubborn, and "bust"). I feel much more comfortable with this snow map than the previous one.
I'll have one more weather blog update coming around dinnertime Monday.