After a relatively quiet start to winter across much of the Northeast and New England, the stage is set for a classic blizzard to impact the region this weekend.
Two separate pieces of energy will phase together on Saturday as abundant arctic air feeds into the system from the west, allowing for a somewhat rare "all snow event" from the Delmarva to Maine.
What meteorologists refer to as a "full phase" of two branches of the jet-stream will result in a rapidly intensifying storm system, with pressure near the center of the storm dropping so quickly it will undergo bombogenesis. This phenomenon occurs when pressure drops 24 millibars or more over the course of 24 hours. Model guidance across the board is in agreement that this will take place beginning later tonight, with some guidance showing a 40 mb drop in pressure from tonight to Saturday night –– more reminiscent of a tropical cyclone than a winter storm.
ECMWF hPa 24 hour forecast (WeatherBELL)
While model guidance had been struggling with the exact path and precipitation shield, last night finally saw a better consensus on what will happen and where:
Light snow is already spreading across the region ahead of the main storm event. These snow showers are associated with the arctic front that will allow temperatures to remain well below freezing throughout the storm.
Nearly half of the eastern seaboard will experience plowable snowfall between now and late Saturday night. Widespread 3+ inches can be expected from the Delmarva to Maine.
A smaller corridor stretching from New York City to down-east Maine will likely see significant snowfall with blizzard conditions at times. Widespread 8+ inches of snowfall and wind gusts of 40+ mph can be expected for this region.
The worst of the storm will occur across a narrow swath that will be difficult to pinpoint until the storm actually forms. Based on the latest model guidance, we believe that swath will stretch from northeastern CT across Rhode Island and into eastern Massachusetts and Maine. This is where we expect snowfall totals of 2-3 feet, wind gusts as high as 65 or 70 mph, and coastal flooding.
Snowfall will come to an end from southwest to northeast on Saturday, with an all-clear by early Sunday morning.
WeatherOptics snowfall forecast & analysis
While the snowfall and analysis map above should remain relatively the same between now and the start of the storm, there is still some uncertainty with exact placement of the heavier snowfall totals.
A deformation band –– the result of rising and unstable air that occurs during intense winter events –– will form to the west of the our storm system late tonight and into tomorrow morning. Figuring out exactly where this deformation band sets up is challenging, even less than 18 hours out, and can make for drastic differences in snowfall totals.
Based on today's mesoscale guidance, wherever this band parks can expect snowfall rates of 3-5" per hour, thundersnow at times, and total accumulations of 20-30+". Multiple deformation bands are also possible. As we've seen with past similar events, some areas could receive more than 3 feet of snowfall from this phenomenon.
We currently believe somewhere between northern Rhode Island, eastern Massachusetts, eastern New Hampshire, and southern Maine has the best chance of surpassing 30 inches.
Impacts to people, places, and businesses
WeatherOptics combines predictive weather modeling with ground-truth impact and geospatial data to deliver actionable insights at a highly localized level.
We account for crucial location-specific differences such as tree cover density, topography, land type, and more using hundreds of variables, allowing for a more accurate impact signal.
Supply chain, logistics, transportation and travel impacts
We're anticipating high to extreme impacts for supply chain and logistics beginning later tonight and lasting into Sunday. Post-storm effects could reasonably lead to issues extending into the early part of next week.
WeatherOptics road danger forecast for11:00 AM ET Saturday
Our Road Conditions Index, which predicts the level of road danger on a scale of 0-10, is showing extreme road danger from Philadelphia to Bangor.
What do we consider to be extreme road danger?
Weather that poses an extreme threat to drivers, with weather-related accidents inevitable, and driving nearly impossible. Widespread road closures with an extremely high threat to life.
Maximum Road Conditions Index over the next 24 hours:
Richmond, VA: 3.7 (low danger) at 2:00 AM Saturday
Washington DC: 4.7 (moderate danger) at 1:00 AM Saturday
Baltimore, MD: 5.3 (moderate danger) at 8:00 AM Saturday
Philadelphia, PA: 8.9 (extreme danger) at 8:00 AM Saturday
Atlantic City, NJ: 9.6 (extreme danger) at 7:00 AM Saturday
New York City, NY: 8.8 (extreme danger) at 8:00 AM Saturday
Hartford, CT: 9.8 (extreme danger) at 11:00 AM Saturday
Boston, MA: 10 (extreme danger) at 11:00 AM Saturday
Portland, ME: 10 (extreme danger) at 1:00 PM Saturday
WeatherOptics RightRoute software
Key freight corridors across the region will see high risk of accidents, significant delays, and road closures. Using our proprietary routing software, here's a look at some of the most at-risk routes:
Richmond to Washington, 6:00 AM departure: 27% slowdown with extreme weather
Washington to Philadelphia, 8:00 AM departure: 33% slowdown with extreme weather
Philadelphia to NYC, 8:30 AM departure: 36% slowdown with extreme weather
NYC to Boston, 9:00 AM departure: 38% slowdown with extreme weather
Boston to Portland, 10:30 AM departure: 69% slowdown with extreme weather
Power and utilities impact
High wind gusts associated with our blizzard will lead to scattered or even widespread power outages, especially near the coastline. With temperatures dropping during and after the storm, this may become a life-threatening situation to those who lose power.
WeatherOptics Power Outage Index for1:00 PM ET Saturday
Here's a look at the most at risk regions:
Coastal Delaware: 10-20% chance of power outages (low) with highest risk Saturday morning
Coastal New Jersey: 20% chance of power outages (low) with highest risk Saturday morning and afternoon
Coastal Long Island: 20-40% chance of power outages (moderate) with highest risk Saturday morning and afternoon
Coastal Connecticut: 20-30% chance of power outages (low) with highest risk Saturday morning and afternoon
Coastal Rhode Island: 40% chance of power outages (moderate) with highest risk Saturday afternoon
Coastal Massachusetts: 40-80% chance of power outages (moderate to high) with highest risk throughout most of the day on Saturday
Coastal New Hampshire: 40% chance of power outages (moderate) with highest risk Saturday afternoon
Coastal Maine: 40-80% chance of power outages (moderate to high) with highest risk Saturday afternoon and evening
Regions further inland will also be at risk of power outages, especially at higher elevations and after the storm has moved through the region.
As temperatures plummet, these outages will quickly become dangerous.
Overall business, day to day activities, and consumer demand impact
As the blizzard moves over its most densely populated regions, changes to regular activities, retail demand, and business operations will be seen.
At the beginning of this week, our partner Consumer Edge released a report that used our Business Disruption Index to figure out how top retailers and brands may be impacted by the blizzard.
WeatherOptics Business Disruptions Index for 10:00 AM ET Saturday
Here's how we expected the some of the biggest cities in the nation to be affected:
Washington DC: 4.2 Disruption Index (low): Temporary disruptions to normal business and industrial operations. Changes to planned activities may be needed.
Baltimore, MD: 4.3 Disruption Index (low): Temporary disruptions to normal business and industrial operations. Changes to planned activities may be needed.
Philadelphia, PA: 6.5 Disruption Index (moderate/high): Significant changes to consumer activity. Scattered disruptions to warehouse and factory operations. Storm preparation recommended and changes to planned activities needed.
New York, NY: 5.3 Disruption Index (moderate): Scattered utility disruptions possible. Minor property damage possible. Preparation for weather conditions is needed as well as changes to planned activities.
Providence, RI: 7.5 Disruption Index (high): Major delays across main highways. Widespread power outages possible. Minor damage to building and infrastructure possible. Storm preparation strongly recommended with impacts lasting for several days.
Boston, MA: 7.7 Disruption Index (high): Major delays across main highways. Widespread power outages possible. Minor damage to building and infrastructure possible. Storm preparation strongly recommended with impacts lasting for several days.
Portland, ME: 7.9 Disruption Index (high): Drastic changes to consumer behavior. Significant disruptions to warehouse and factory operations. Road closures likely. Impacts could last several days or more.