Crippling Winter Storm Stella Likely: Forecast
- Jackson Dill
- Mar 13, 2017
- 4 min read
As we get even closer to the main event of Winter Storm Stella, the confidence of what will happen with this storm is finally increasing. To sum up what I'm going to talk about below, a crippling and paralyzing winter storm is likely to impact the I-95 corridor and most of the Northeast with blizzard conditions, very heavy snow, and coastal flooding.
Threats:
Very heavy snow from Tuesday morning through Tuesday evening.
Blizzard conditions for most of the area much of Tuesday.
Scattered power outages likely due to wind gusts up to 60 mph.
Very dangerous and treacherous travel.
Coastal flooding up to 2 to 3 feet above normal tides.
Current Alerts:
A Blizzard Warning is in effect from 12AM Tuesday through 12AM Wednesday for all locations.
There is also a Coastal Flood Watch in effect for the southwestern Connecticut coast. This will be in effect from 12PM through 3PM, which is during the peak of high tide.
Discussion:
As mentioned earlier, the confidence in our forecast has increased because the models are finally beginning to hone in on a similar solution. In short term: a major winter storm is on the way. I have been emphasizing how important the track and position of the low pressure system is. We now know that it is likely to pass either directly over the 40/70 benchmark or north and west of there. This track is favorable to heavy snow for our area. The EURO ensembles below show the clustering of the low pressure just near that 40/70 benchmark.
These ensembles also give chances for certain amounts of snow. These chances are insanely high for significant snowfall. They give all of our area a 99.9% chance for at least half a foot (six inches) of snow, which is unbelievable alone. At least you know we're going to receive at least this amount!
There is also an 80-99.9% chance for at least a foot of snow, which is also pretty high considering that snowfall amount:
Then when we look at the chances for at least 18 inches, or a foot and a half, of snowfall, there is an unprecedented 20-30% chance:
Winds will be significant as well. These winds will contribute to the likely blizzard at least for the coast. The European model is especially bullish on the speeds of the wind gusts, but they are reasonable based on the track and the strength of the hurricane-force low. Check out the map below, which shows gusts up to between 60 and 65 mph for our area. This will certainly lead to downed trees, further resulting in power outages.
The EURO ensembles also show significant support for these strong winds. This map below shows the probabilities for wind gusts of at least 46 mph, which range from 50-90% in our area. As you can tell, there is a very sharp cut-off line between where those strong winds will be, so there is still some wiggle-room for either weaker or stronger winds.
Temperatures will be below freezing for the entire snow event for southwestern Connecticut, but the coldest of air will be inland. At the coast, temperatures will begin at the freezing mark, then dropping to the mid 20's by the evening. For the interior towns, temperatures will remain in the mid 20's from start to finish. The reason why this is important is because it contributes to how much snow you will get. The warmer the temperature is, the more dense, heavier, and wetter the snow is. The colder the air is, the lighter and fluffier the snow is. At the coast, it will go from wet to fluffy, whereas inland it should be a light and fluffy. Therefore, slightly higher snowfall totals can be expected in the interior. This wet snow will also contribute to an elevated power outage chance at the coast because the heavy, wet snow combined with 50-60 mph will weigh down the trees and branches and blow them over.
Now let's talk about snowfall totals! All of the models are agreeing on similar solutions in terms of snowfall, give or take a few inches.
Here's what the models predict for Danbury, CT, factoring in the high snow to liquid ratios, or dry and fluffy snow, due to the cold air:
European (EURO): 25 inches
American (GFS): 14 inches
Canadian (CMC): 23 inches
North American Model (NAM): 18 inches
European Ensemble Mean (EPS): 16 inches
Now here's what the models predict for Bridgeport, CT, factoring in the low to high snow to liquid ratios, or wet to fluffy snow, due to the cooling temperatures:
European (EURO): 24 inches
American (GFS): 13 inches
Canadian (CMC): 19 inches
North American Model (NAM): 15 inches
European Ensemble Mean (EPS): 15 inches
Forecast:
Now it's time I give my official Jackson's Weather forecast for Winter Storm Stella. The snow will begin between 2AM and 5AM, continuing all day long, then winding down in the middle of the night Tuesday night. The heaviest and most crippling, treacherous parts of the storm will occur during the majority of the daylight hours Tuesday. That's when we can experience snowfall rates of two to even four inches per hour! Then on Wednesday, a few light snow showers are possible on the backside of the low, but the main event will be over by then. Only a coating to an inch may accumulate Wednesday. All of the accumulating snow will happen on Tuesday.
For Tuesday, I am now forecasting between at least 18 and 24 inches of snowfall.
I am leaning toward the higher end of this range, though, because my favorite and very reliable EURO model has been consistently forecasting around two feet.
Model data maps courtesy of WeatherBELL.
Stay with Jackson's Weather through the event of Winter Storm Stella for constant updates online and on social.
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