Well, we're 4+ days out from the start of the likely storm late Wednesday evening and we're seeing some shifting around in the models, as usual, but the signal for at least a significant (4-8" is my definition of "significant") to major storm (8-14" is my definition of major) has increased, while the signal for an historic storm (14-24" is my definition of historic; we've had 24 such storms in 155 years in NYC, for example and similar numbers for NB) has decreased a bit, i.e., we might be looking at a higher floor, but a lower ceiling. Note I'm using the Kuchera snowfall estimates as this is likely going to be a pretty cold storm with temps in the 20s, so >10:1 ratios are very likely.
This is because the two outliers showing just a coastal scraper (significant snow only for SENJ really with minor to moderate snow for 95 and NW), the GFS and the Euro-AIFS (AI model), came NW significantly and now show a significant storm (AIFS) to a major storm (GFS) for just about the whole Philly-NJ-NYC region. On the other hand, the Euro which has been showing historic snowstorms for the region for a few days has backed off significantly showing only 3-6" for 95 and NW and 6-10" towards the coast; no idea if that's a blip or not. On the other other hand, the CMC continues to show a major snowstorm, while the UK is showing an historic snowstorm, as is the ICON. The fact that all of the models are at least showing a significant storm and most are showing at least a major storm with a couple of those showing historic storms tells me that the floor has been raised, but the ceiling has come down some. Also, the ensemble means continue to indicate at least a significant snowstorm.
None of this means that there can't still be major changes, since we're still 4+ days out, but the chances of a complete out to sea miss or a snow to mostly rain cutter are both very low now, whereas there is still a decent chance of a coastal scraper (minor snow for 95 and significant snow only towards the coast) or an inland runner that puts down 6"+ for most, but then turns the precip to mostly sleet/rain for 95 and SE of 95, while hammering areas well to the NW of 95 with a major snowstorm.
I'm not going to microanalyze the global models other than to say numerical weather prediction is still chaotic, meaning uncertainties 4 days out are still moderately high and the difference between a coastal scraper and inland runner is only about 100-150 miles in the track forecast, which isn't bad, actually since the "storm" won't even be on the map for 3 days (the pieces that form it are all pretty far away still and have to come together just right for a major snowstorm. Also keep in mind that if we get a major to historic (still on the table) snowstorm, which becomes quite powerful, blizzard conditions or close to it would be possible with gusty winds, plus minor coastal flooding could be an issue for a powerful coastal storm (this looks like a "Miller A" that skirts across the Gulf states then heads NE up the east coast). All of the relevant maps and deeper discussion are in the AmericanWx thread below and I included a link to Tomer Burg's nice explanation of the meteorology and some potential outcomes.
https://www.americanwx.com/bb/topic...time-between-18z-wed-219-12z-fri-221/page/16/
2/16: Changed thread title from "OT: Significant to Major Snowstorm Possible for Thursday 2/20" to current thread title
2/17: Changed thread title from "Winter Storm Thursday 2/20: Could range from a miss (most likely) to a minor event (possible) to a moderate event (unlikely)" to current thread title
This is because the two outliers showing just a coastal scraper (significant snow only for SENJ really with minor to moderate snow for 95 and NW), the GFS and the Euro-AIFS (AI model), came NW significantly and now show a significant storm (AIFS) to a major storm (GFS) for just about the whole Philly-NJ-NYC region. On the other hand, the Euro which has been showing historic snowstorms for the region for a few days has backed off significantly showing only 3-6" for 95 and NW and 6-10" towards the coast; no idea if that's a blip or not. On the other other hand, the CMC continues to show a major snowstorm, while the UK is showing an historic snowstorm, as is the ICON. The fact that all of the models are at least showing a significant storm and most are showing at least a major storm with a couple of those showing historic storms tells me that the floor has been raised, but the ceiling has come down some. Also, the ensemble means continue to indicate at least a significant snowstorm.
None of this means that there can't still be major changes, since we're still 4+ days out, but the chances of a complete out to sea miss or a snow to mostly rain cutter are both very low now, whereas there is still a decent chance of a coastal scraper (minor snow for 95 and significant snow only towards the coast) or an inland runner that puts down 6"+ for most, but then turns the precip to mostly sleet/rain for 95 and SE of 95, while hammering areas well to the NW of 95 with a major snowstorm.
I'm not going to microanalyze the global models other than to say numerical weather prediction is still chaotic, meaning uncertainties 4 days out are still moderately high and the difference between a coastal scraper and inland runner is only about 100-150 miles in the track forecast, which isn't bad, actually since the "storm" won't even be on the map for 3 days (the pieces that form it are all pretty far away still and have to come together just right for a major snowstorm. Also keep in mind that if we get a major to historic (still on the table) snowstorm, which becomes quite powerful, blizzard conditions or close to it would be possible with gusty winds, plus minor coastal flooding could be an issue for a powerful coastal storm (this looks like a "Miller A" that skirts across the Gulf states then heads NE up the east coast). All of the relevant maps and deeper discussion are in the AmericanWx thread below and I included a link to Tomer Burg's nice explanation of the meteorology and some potential outcomes.
https://www.americanwx.com/bb/topic...time-between-18z-wed-219-12z-fri-221/page/16/
2/16: Changed thread title from "OT: Significant to Major Snowstorm Possible for Thursday 2/20" to current thread title
2/17: Changed thread title from "Winter Storm Thursday 2/20: Could range from a miss (most likely) to a minor event (possible) to a moderate event (unlikely)" to current thread title
Last edited:
