Just before bedtime I wrote about how the GFS’s 00Z run had backed off on precipitation for Friday’s major event. I added, “The GFS is seldom my first choice.” The difference between the 00Z and 12Z runs is a prime example why!
The Euro is in and its solution for Friday/Saturday is sobering. Feet of snow and scattered blizzard conditions seem the most likely scenario. A storm like this can quickly turn a below average winter into something you’ll long remember.
Before I get into specifics, allow me to give you some advice. A storm like this can quickly get ahead of anyone who tries to challenge it. People will attempt to travel in marginal conditions only to find those conditions rapidly deteriorate stranding the traveler. A storm like this can kill.
Machismo will not serve you well! Plan on sheltering in place Friday evening into the weekend.
There’s been a lot of talk about two systems combining. Sort of, though that’s misleading.
The majority of what we’ll get comes from the coastal low in the map at the top of this entry. It and an inland low will phase, allowing the western storm to shape the path of the coastal storm.
The second low is why this Nor’easter bends slightly north instead of steaming directly out to sea. Bending the path keeps it closer to us for a longer period of time.
Mo snow. Mo problems.
Friday AM – Friday afternoon
The storm’s first moisture reaches us around daybreak. The latest GFS and ECMWF runs are cold enough to wonder if any rain will be mixed in–even on the shore! Certainly the beginning of the storm looks like light snow everywhere.
By early afternoon you’ll be saying, “Where’s this blizzard they’re talking about?” The midday snow shouldn’t be too bad.
Schools could open–but they probably won’t. They probably shouldn’t. Most school districts have plenty of banked snow days to play with¹. Be generous. Err on the side of caution.
At cloud level the warmest air arrives early afternoon. That’s the most likely time for any rain or mixed precipitation near the shore. If you’re all snow through 2:00 PM, you’re all snow for the storm!
Afternoon drive will be a mess. 3-6″ already on the coast, a little less inland. All the slippery is in the first quarter inch!
The intensity of the snow begins to ramp up. The temperature drops.
As a rule of thumb, road crews can keep up with 1/4-1/2″ of new snow per hour. By evening we’ll be seeing 2-3″ per hour. Secondary roads will become impassable. Interstates will be treacherous.
As the Sun goes down, the wind picks up. First the shore, then inland (especially the I-395 corridor) will feel gale to tropical storm force gusts. There are Blizzard Watches/Warnings up already. This is why.
By midnight some areas will be approaching a foot on-the-ground with blowing, drifting snow and near zero visibility. The storm center will be east of Atlantic City, south of Narragansett Bay–in the Atlantic, but likely its closest approach to us.
Heavy snow. Strong winds. Very cold. Blizzard conditions (or nearly so). Coastal flooding at high tide.
I can’t overemphasize how dangerous it will be to leave your home during this time. If you’re walking the dog, stay within sight of your house/apartment–seriously.
Another foot (or more) will fall over portions of the state through the night. By this time accumulation numbers will be meaningless. Too much snow for sure.
There will be enough snow weight to weaken/damage/collapse a few roofs!
In spots, blowing and drifting could trap people in their homes!
By dawn the wind will begin to diminish in intensity. The snow too. Another few inches are possible before all is said and done around noon.
Earlier I had an IM chat with my meteo prof friend, Bob in Florida. I’ll let you eavesdrop.
Bob: wow, looks like euro targets CT
lots of banding on back side
through 48hr dry slots groton to providence, but pounds new haven to white plains, no totals, but i’d guess over 2″ liquid
this is all a product of the phasing with the second, western, low.
Bob: ideal phasing, which the euro has been hinting at all the time
me: look how it bends hard left as we approach 48h
nws will issue blizzard warnings state wide if they buy euro
me: and they will. I think we’ve all come to the conclusion it is vastly superior to any US model
It must be a sad time to work at NCEP or MDL
Bob: i don’t see any 850 > 0C air
on euro in CT
i think -2C at shoreline is warmest
It’s been a while since we’ve had weather like this, thankfully.
¹ – Correction – Because of Sandy many districts used their spare days long before winter arrived. I apologize for the error. H/T Jim McGuire.