RU848789

Amazing consensus at 0Z for the meso/hi-res models I've seen for at least the Philly-NJ-NYC region...NWS is likely going to raise accumulations SE of 95 based on these unless we see something odd with the globals... The NAM shows a general 4-6" event for literally everyone except 2-4" for Cape May and 6-8" for NYC and NE-ward The NAM 3km (high res) shows a general 3-6" even everywhere except for SENJ south of Toms River, which get 1-3". The HRRR shows a 4-6" event for almost everyone, except 2-4" for SENJ south of Toms River The RAP shows a 4-7" event for everyone, except 2-4" for AC to Cape May. The HRW-FV3 (will be the new NAM someday) shows a 4-7" event for everyone, except 0-4" for SENJ south of Toms River

Been telling people, especially those who get some mix/slush in their snow pack, to shovel during the event and right after it or else they're going to have a rock solid pack in the morning and yes the salt on the streets will melt some of the snow to make it slushy and that piled up mass will freeze solid wherever the plows leave it - could make tight city streets a nightmare.

Here's the precip field; of course verification awaits (which is highly likely overall - there are always parts of a forecast that don't work perfectly for every model), but this is impressive

Hands down the best performing model for this event, based on memory, so I was curious and made these two GIFs of the surface low placement at 0Z Sunday and the 24 hour precip field through 06Z Monday and the consistency over 8 runs is astonishing and iirc, this consistency goes back 4-5 days.

Great, thanks!

Hey - I know you're the Euro AIFS snowfall map guy - have you posted an updated version? Thanks. I couldn't figure out how to do a search for your posts - used to be easy, maybe they changed how that's done.

@donsutherland1- hey Don, I recall you recently posted about significantly increased chances for NYC (and I think other 95 cities) to get major snowstorms during a regime shift with the cold and high latitude blocking relaxing (and other shifts), but I couldn't find it. Would any of that be in play for 1/24-25 (I see some signals on some ensembles)? It's obviously warming up by then and the latest forecast I saw was for the NAO to go positive around then. TIA.

Why oh why is anyone looking at the HRRR beyond 18 hrs? It's crap beyond then. I think it was the little 1/8 SNJ storm where the HRRR was showing 4-5" at ~24 hours out; most got <1". There are other examples.

This storm is no longer in fantasy land as we're now within 4 days of the start of the event in Texas. The CMC has been on this for days and the Euro/GFS are also on it, so even the NBM is showing a decent snowstorm. Crazy for this region. Houston's biggest snowfall ever was 20" in Feb 1895 and so was New Orleans's with 8.2", but they haven't had measurable snow in 15 years. https://www.nola.com/news/weather/snow-day-new-orleans/article_93ca617c-d354-11ef-ac9d-dfa183f2d62b.html .

NWS-NYC finally corrected their map and reissued. No longer completely inconsistent with Mt. Holly's map...and Mt. Holly just put out the regional map which I like...

Thanks although it's still wildly inconsistent with the Mt. Holly map in NNJ - it's like they grafted the new OKX map onto the old Mt. Holly map. They need to do better.

The NWS NYC map below makes no sense as there are watches up for 5-8" for much of the CWA...and obviously no collaboration between offices...Mt. Holly must be factoring in high ratios NW of 95

It's supposed to be rain at 12Z Sunday (7 am EST) as the cold air hasn't moved in yet. And stop looking at the 48 hr HRRR, the one that predicted 6" for that little SNJ 1" storm around 1/9.

Been snowing lightly off and on for a few hours and we have a decent coating of about 1/4" on all surfaces, given how cold it's been. Could be some slick spots out there. Nice surprise as I wasn't expecting much.

Great trends today and some thoughts looking ahead. Nice to see the NWS and other forecasters are now all playing up the snowfall potential as expected based on those trends, with the NWS now calling for a general 2-4" snowfall for everyone along and NW of 95 through 7 pm Sunday (noting there will be more to come) except maybe just 1-2" towards the coast (especially SENJ), but also noting that more is possible than that and less if the Euro is right, plus they acknowledge the risk of mixing/rain up to 95 as shown on the CMC.Lee Goldberg also has just about everyone at 2-4", with 1-2" south of Toms River and for far NW areas (Poconos/Catskills), but he also noted that there will likely be some 4-6" amounts, most likely from NYC on NE-ward but maybe even back towards CNJ. Precip looks like it will start by 1 pm towards Philly/SNJ (where game impacts are looking much more likely than yesterday) and by 3-4 pm in CNJ/NYC and will continue with temps likely falling into the 20s and precip going until 1-3 am Monday. Whatever accumulates will be with us through next week with the bitter cold coming. In addition, as many have discussed, there's an increased likelihood of snow ratios >10:1 with the snowier solutions, which are more likely to have good lift/supersaturation/crystal growth in the DGZ, as well as not suffering from column melting/aggregation with very cold column (except for CMC style outcomes where precip type is in question or at least falling snow could be very wet and lower ratio). https://forecast.weather.gov/produc...&format=CI&version=1&glossary=1&highlight=off National Weather Service Mount Holly NJ 354 PM EST Thu Jan 16 2025 .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... From here, forecast guidance varies greatly and ultimately will determine what will occur Sunday afternoon into Sunday night. If the track of the low is close enough to the coast, a large portion of the region is likely to observe accumulating snowfall (similar to what the 12Z/GFS depicts). If the track of the low is suppressed further south and east (similar to the 12Z/ECMWF), then accumulating snow may only be confined to coastal areas. Whereas if the track of the low, hugs the immediate coastline, then the most significant snows will be focused north and west (depicted by the 12Z/Canadian). Regardless of the variance in global guidance, have seen an increase in overall QPF values and in snow probs. Thus, there is an increase in forecaster confidence that accumulating snow is on the table Sunday afternoon/evening especially since cold air will be advecting in from the northwest. So with this being said, the greatest potential for higher accumulations are for areas along the I-95 corridor and points north and west where the initial forecast calls for 2-4" of snow through 00Z Monday. Lesser amounts upwards of 1-2" are forecast near coastal areas through the same timeframe. Obviously, a lot can change over the next 60-72 hours as we obtain more hi-res/short range forecast guidance and storm total snowfall covers the `full duration` of the event, so stay tuned for the latest details to the forecast over the coming days!

Thanks!!

You are the man with the AIFS snow maps, so, please? If not out yet, it shows a general 0.3-0.5" of QPF with temps at about 32F to start for most but dropping into the 20s, so ratios could easily exceed 10:1 (3-5" at 10:1 or maybe 4-7" with good ratios) if we get good snow growth, given a likely cold column for most of the event. Verbatim.

Thanks, as always. Do you (or maybe @bluewave) know when was the last time we had below normal temps for both Dec/Jan? Feels like many years, but I don't track temps closely.

Nice, more like 0Z, but even better than that and way better than 06Z...

I've asked several times if there are snowmaps for the AIFS (they're not on Pivotal or TT, so one has to guess from temp/precip maps) and no replies, lol, so nice to see this map, thanks; wonder if WeatherBell has them. As this model has been performing quite well this winter, we might need you StormVista folks to post these maps. :>)

I assume you're referring more to the 1/24 possible event not the 1/19 event, which is nice, but not spectacular for our area. I get it, but I'd way rather get snow like the Euro/AIFS are showing for 1/19 and then hope for something 5 days later.

Argues for an Op outlier to some extent. Would be nice.

Euro looks very similar to the GFS at the surface.

Can't believe nobody posted the UK which is a nice hit and while it's not as amped/snowy as the CMC I might rather get 2-4" guaranteed with temps in the 20s (3-6" if we get good ratios which is possible) than the potential for lots of mixing/rain along and SE of 95 like the CMC. And the UK down south would be absolutely nuts; 1989 redux for the GA/SC/NC coasts. I have relatives in Charleston and Savannah and they all thought th 1989 storm was one of the most amazing things they had ever seen, even though they're not snow lovers. I almost want them to get that and us get nothing. Almost, lol.

Just got on line (poker night) and first thing I look at is the CMC - crazy - has us at about 5", but 10 miles NW is 7" and 10 miles SE is 1". Easy forecast, lol. More importantly, nice move back SE without losing its "amp-ness."