Made slight adjustments to snow map to account for more mixing with sleet possible. Impacts will be the same however on both commutes tomorrow. There could be a few spots esp north that see over 12. Gets going after midnight through the day tomorrow. Will start to see sleet work it’s way in from 7 to 10am from south to north then back to snow on the back side in the early afternoon.
Here is Snow Map focused on CT. 8-14 inches is a good bet throughout interior SNE, mixing makes it’s way to the coast by mid morning Monday with lots of pingers and freezing rain. Some Ice accumulation possible. Further inland lots of fluff. This things gets going after midnight Sunday and goes all day Monday with the worst between 7am and 1pm Monday where 1+ inch an hr rates of snow will be common. Both Monday commutes look horrendous at this point. Plan accordingly. There could be a few spots with a little more or less than the totals on this map. If it busts (meaning more sleet) everyone should still get 6. If it booms you would see more widespread 12+ to as much as 18. The most likely solution is the deterministic amounts shown and think of the bust and boom as the upper and lower echelons of probability.
** Some final thoughts as the Blizzard of 2015 exits. **
The storm is winding down, Boston and Eastern Mass looks like the jackpot zone, Worcester, PVD and BOS are all approaching record snow. As I highlighted in my forecast where ever the NW deformation zone would set up would get slammed with 30 inches and there would be a sharp cutoff to the west. Western CT on west down to PHL was a bust by basically everyone in the weather community. The storm took a few extra hours to be captured by the mid level jet stream and therefore the surface low went about 30-50 miles east with the heaviest snow axis. Some of our computer models suggested this was going to happen but with experience and the very consistent ECMWF model deterministic forecasts from NWS and most others called for 2 feet or more in NYC. That didn’t happen but just 30 miles to the east in LI they got slammed with said totals. The northeast is an extremely small place compared to the entire earth so it’s pretty amazing that we can model the real world to get a storm track within 50-100 miles. The entire Contiguous US is only 1.5percent of earths’ surface. Think about that. There is always uncertainty involved in trying to predict a nonlinear dynamical system like the atmosphere. It cannot and will not ever be perfected due to chaos theory. However it will continue to improve with growing resources and technology. I thought overall the job by Meteorologists and Emergency managers did a great job getting people prepared for a truly dangerous storm. The media hype yesterday in NYC was in my opinion outrageous and although this storm was serious the media needs to help convey the message we Meteorologists do and that is probabilistic forecasting. There was a good chance NYC was going to be buried so that’s why the going forecast by NWS was what it was. I understand people are upset and are asking questions, however you need to understand we do not have crystal balls to predict the future, we use science and technology but there are limitations. We try to pinpoint the most likely solution. We learn from every storm and add it to our experience. I know I learned a lot from this storm and will use that knowledge for the future. Also, I would much rather have overpredicted and have people safe than underpredict snowfall and have hundreds of people stranded and freezing to death in heavy snow and 20 below wind chills.
Also, we are headed into a very cold pattern with multiple snow chances so keep tuned.
This one is a potentially historic wind driven blizzard and it’s set to begin tomorrow afternoon and rage tomorrow night into Tuesday. Here is my thinking right now for the storm. Where best banding sets up, somebody could get 3 feet, it’s not out of the question. Latest data suggests a potential max from NYC, Hudson Valley through the Berkshires and another one in Eastern Mass including Boston. This is where you could see 30+ but it’s really hard to say where the best mesoscale banding will set up at this point. In the heaviest banding there could be as much as 2-4 or even more inches per hour! Based on where the 850/700mb low’s track will determine this and where the best frontogenic forcing will be. Cold high pressure to the north in perfect timing with this storm will only help it strengthen. Surface temps should be generally in the 20’s but dropping into the teens late Monday night into Tuesday. A bit of uncertainly on the Cape and Islands where there could also be some mixing issues, could be more like 6-12 there possibly with some rain especially on ACK. This things gets going tomorrow afternoon and cranks tomorrow night and Tuesday am. All in all, a textbook setup for a classic, potentially historic Nor’easter with 1-3ft of snow from PHL to BOS. Not to mention winds gusting to 50mph inland and 60-75mph on the coast. Reaching Blizzard criteria officially means 3+ hrs of sustained winds of 35mph or greater and reduced visibility of under a 1/4 miles. Blizzard Warnings have been posted by the NWS for NYC, all of CT and Boston.
Updated Snow Map for tomorrow’s storm. Mixing issues SE as I talked about in yesterday’s blog post. Begins early tomorrow am. Travel will be affected tomorrow so take note.
A powerful winter storm is headed for the Mid-Atlantic and Northeast Saturday. A shortwave deepening in the Southern US will create strong development of a surface low and it will track northeast Saturday and eventually right near or over the 40N/70W benchmark Saturday evening. Computer model solutions have been waffling a little bit but most have come into agreement a track right near the BM and this is where my forecast track is. Usually that track is great for I-95 for heavy snow, not this time. We have no arctic air injection before the storm and therefore the air mass in place is very marginal with temps through all levels of the troposphere. Therefore, I’m favoring snow changing to rain in the big cities while inland areas will see more snow especially in interior Southern New England. I think DC/Balt start as snow early Sat morning and sees a coating to 2 inches before rain. NYC more like 1-3 before rain and a little snow on the backside Sat afternoon. SE CT and SE Mass not including the Cape I like 2-4 with a coating to an inch or so before rain on the Cape and Islands. Everyone goes back to snow however as the storm pulls in cold air on the backside Saturday evening. Further back NW starting in Eastern PA, a narrow band of 3-5 from Harrisburg to Allentown and NW Jersey. I like 3-6 for Interior CT including Hartford area. From NE CT through Worcester hills to the west suburbs of Boston I like 4-7 could see an 8 somewhere. Boston metro I’ll go with about 3-6 as well, don’t think the city will see more than 6. The rain/snow line will be pesky as mid level warmth floods in with a rapidly deepening cyclone and no real cold air to work with. This is why the coast goes over to rain but changes back to snow on the backside. There will be a sharp cutoff of precipitation to the NW due to lack of a great baroclinic zone again without that arctic high. This will reduce isentropic lifting to the NW and create a sharp NW cutoff from moderate precip in Hartford, CT to nothing in Albany, NY. Stay tuned for updates…
A side note:
Fun times ahead as this pattern is now turning more favorable for winter storms, Monday there is another possible snow event but it’s unclear right now how that will turn out. After that it gets VERY COLD over the next few weeks, well below normal temps may stick around for most of February.