A Premium update has recently been posted for Premium Subscribers. You may subscribe here if you would like to access our Premium content and get it emailed directly to you. Due to the severity of this storm, however, relevant portions of the Premium updates will be publicly released to alert of the numerous dangers with the storm. Attached below are those portions of this morning’s Premium discussion:
First, the National Weather Service, in reaction to the overnight weather model suite, lowered snowfall totals across the region. Their forecasts are now for 18-24 inches of snow with locally higher amounts, inside of my 16-28 inch range. As my range covers 3 counties and is built to account for both enhanced mesoscale banding and a drier slot, this makes sense for my range to be a little broader and account for still a number of scenarios. It is comforting too to see the NWS revise down slightly, as it shows there was merit to the idea last night that they may have jumped the gun. Ironically, now that they have changed their forecast, their original idea of widespread 2-3 feet may be getting more support from weather modeling. But first, I just want to say that the forecast is staying entirely firm, as I see no region to change it. It remains 16-28 inches region wide, with the higher amounts more likely in eastern areas than western ones, and amounts to 30+ inches possible in the heaviest banding. Someone could possibly even see three feet, but it is just really a matter of where the heaviest precipitation sets up and trains. I am not confident enough to hold that 3-foot range in my forecast, however, so I’m sticking with the going range, and adding the range of “isolated amounts of 30+ inches possible in heaviest banding,” which I think should cover any extreme convection.
In summary of this part of the forecast, 16-28+ inches, with the lower amounts in Westchester and the highest amounts likely near New Haven, remains the going forecast for this upcoming storm. Blowing and drifting of this powdery snow will make it almost impossible to measure regardless, however. And conditions between those that get 16 inches and those that get 28 inches may actually be quite hard to distinguish, as they will both be very difficult. It is clear, too, that the wind forecast was not overdone. The NWS is calling for gusts only in the 45-55 mph range, but that’s quite close to my 50-60 mph range. I would not at all be surprised to see someone exceed 55 mph due to the strength of the low pressure center. For example, the SREFs here show sustained winds in coastal New Haven County over 30 to maybe 35 mph at 4 AM tonight. It would not take much more to push that up a little more.
What that means is that for power outages, they remain most likely across New Haven County, and the first likely begin to get reported around 1 AM tonight or so as the stronger winds move into the area. If you have not already, please get the necessary supplies to spend multiple days without power with subzero temperatures. Temperatures get into the single digits tomorrow night and may get below 0 with the snowpack Wednesday night, so it is crucial you make emergency preparedness plans in case you do lose power in this storm.
I originally had the heaviest snow outlined as between 1 and 10 AM, but I’ll extend that out to 1 to 11 AM now as models indicate that the strongest banding could see very impressive forcing through at least 11 AM tomorrow in some areas. Expect snowfall rates of 2-4 inches per hour possible in the heaviest banding through that 10-hour timeframe along with the strong potential for thundersnow, where the convection is strong enough to actually create lightning and thunder in the banding. Thundersnow is most likely between 2 AM and 8 AM from what I am seeing, so do not be surprised to be awoken by a clap of thunder or two.
Right now, I would advise being off the roads by 4 PM if possible. And by the time it gets dark roads will certainly by slippery with a couple inches of snow on them. And by 7 PM conditions are really deteriorating. CT issued a travel ban at 9 PM, and I believe that is the right decision. It is looking like right around 9 PM is when conditions get so serious that traveling could put your life at risk. Travel between midnight and noon tomorrow will just simply be life-threatening, there’s really no better way to put that. Snow falling as heavy as some models show in the heaviest bands could trap cars on roadways, and this is an extreme blizzard with wind gusts in the single digits to below 0 at times, so there is no excuse for travel overnight tonight. Just hunker down and prepare.
That’s really the latest update covering all the latest morning trends. Again, it all comes down to how far west this major convective band can build. If it builds far enough west to significantly impact the region, we are looking easily at 20-30 inches of snow. If it doesn’t make it quite as far east, we are looking more at 16-24 inches of snow. Still sizable, but cuts about 6 inches of snow off the totals as snow will not be quite as intense at the height of the storm. As our extremely short-range guidance begins to get into range on this (most accurate at predicting the banding), I’ll be sure to keep you updated on the latest. One thing is for sure: once the sun goes down, hunker down, and prepare for a storm that you will be talking about for awhile. This still has the potential to be historic. As I said yesterday, this is the big one. There’s no reason to mess with it. An additional free update will be posted this evening around 4 PM, with one possible around 1 PM if conditions dictate.