RU848789

Going to be an interesting modeling battle from now until the event on when and if and where any mixing/changeovers occur and how much snow falls before any mix/changeover. I hope Mt. Holly is right about all snow N of 276/195, essentially. One comment for those who don't love snow (and who might root for less snow here): I think you'd rather have 15" of snow (which is easy to move) than 10" of snow, 1" of sleet and 0.2-0.3" of freezing rain on top, as the latter will lead to compaction and a fairly quick freeze into a potentially solid mass within a few hours, as temps in areas where we see freezing rain/rain will dop well below 32F within a few hours of the precip ending - temps everywhere will be in the mid-20s everywhere by Monday at 7 am and will stay there during the day with Monday night lows around -5 to +5F - and it might not reach 20F again until next Sunday. It's going to get really cold.

Didn't see this posted. A bump up from 07Z. Their snowfall seems much higher than any model (at least at 10:1, so their "model ratio looks to be 15:1 for the 95 corridor at least, comparing snow to QPF), which is unusual. I don't care if some of this near the end is really sleet - this would be amazing.

Not sure if folks will find this useful, but I post this model summary info in a few other places (FB/non-weather forums/my email list) and folks seem to like it, as it provides a decent summary without posting 14 maps, so thought I'd see what people thought. These are model summaries from 0Z for CNJ and the immediate PA counties bordering CNJ, i.e., areas between 276/195 and 78, as well as for NENJ (eastern Union/Essex and Hudson) along 95 and NYC. I also include the estimated snowfall amounts at both 10:1 and 15:1, which is my guess for ratios we'll see (I know some think we'll see higher, but I'm not ready to go there yet), plus I included the same info from the 12Z runs of these models. GFSAI isn't included as I don't have direct snow info for that model (but we know it's no longer an outlier based on QPF). As an aside, I've never seen model consensus like this 4.5 days out (or maybe even 4.5 hours out, lol. Comments welcome. The Euro shows 10-12" at a 10:1 ratio and 15-18" at a 15:1 ratio and the 12Z run was 7-10". The Euro AIFS shows 8-11" at a 10:1 ratio and 12-16" at a 15:1 ratio and the 12Z run was 5-8." The GFS shows 8-11" at a 10:1 ratio and 12-16" at a 15:1 ratio and the 12Z run showed nada for CNJ. The CMC shows 10-13" at a 10:1 ratio and 15-20" at a 15:1 ratio and the 12Z run was 7-11". The UK shows 10-13" at a 10:1 ratio and 15-20" at a 15:1 ratio and the 12Z run was 9-12". The ICON shows 8-10" at a 10:1 ratio and 12-15" at a 15:1 ratio and the 12Z run was also 8-10". The NBM (model blend) shows 11-14" at a 10:1 ratio and 16-21" at 15:1 ratios and the 12Z run was 8-12".

Quick post-mortem on the Saturday and Sunday snowfalls around here - I usually do these for the Philly-NJ-NYC region so thought I'd post one here. Basically, the models did a lousy job in the 2+ days out timeframe with little consistency and most being wrong, showing maybe 1-2" N of 78 on Saturday and nada south of there and showing maybe 1-2" for the coast and towards 95 on Sunday, with very little NW of 95. The forecasts prior to 2 days out were similarly underdone for most compared to what occurred. Fortunately, the models did finally move toward what we saw and the NWS forecasts (and other forecasts) about 18 hours before the start of each event (see the two NWS forecasts below) were generally pretty good relative to what actually occurred, as shown in the two snowfall maps below, with a few exceptions. First, on Saturday, the forecast for 2-4"N of 78 and well NW of 95 and S of 78 did well, but the snow from the clipper ended up being 1-3" for most of the 95 corridor, which has been predicted to get <1" - more cold air moved in with the precip along 95 keeping it as accumulating snow instead of white rain or a mix. Second, the forecast was for 2-4/3-5" for NENJ, NYC, LI and the Hudson Valley, but those areas generally only got 1-3" (due to less precip falling vs. what was expected). The other modest miss was on Sunday where the NWS forecast was for 1-3" for far NWNJ, the Poconos and most of EPA while the outcome was 3-5" for most of that area - most of the models were showing less precip due to being further from the coastal low. FYI, we got 2.2" on Saturday and 1.7/2.4" in rounds 1/2 on Sunday for 4.1" total and 6.3" for the weekend. Up to 17.5" for the season.

While this is the NYC subforum, it's worth noting that there is likely going to be a crippling ice storm with 1" or more of ice accretion in a fairly wide swath from Texas to NC on Saturday into Sunday – where exactly that sets up is not a given yet – and north of the ice storm, 8-12” snowfall amounts are looking likely from northern Texas to northern TN/NC and into VA. This could be an historic US winter storm if the current models verify: see the nationwide snowfall and ice accretion graphics from the NBM model...

I saw that, too, but thought it was an older source. It should be easier to find this kind of info, lol.

Ok, but the NBM is their bible, so if it's showing 6" of snow, the WPC map ought to reflect that IMO.

Exactly. Anyone who claims to be a scientist of any kind can't possibly believe in jinxes - how one ties one's shoes, wears a cap or posts on an internet weather forum has no bearing on the outcome of any event. It's just dumb.

According to Google AI it does, lol, but none of the links provided showed that, but I may have missed them as the NOAA/NBM model sites are fairly obtuse to navigate. https://www.google.com/search?q=are+AI+models+incorporated+into+the+national+blend+of+models+nbm%3F&sca_esv=19fb1bea8894757c&hl=en&biw=1536&bih=791&aic=0&sxsrf=ANbL-n5dmwLPcf4aXzuAo62-IxWijdkJ8Q%3A1768855885220&ei=TZluaY2UDauw5NoP_M6SKQ&ved=2ahUKEwj7187kvZiSAxUMKVkFHbE0GoIQ0NsOegQIAxAB&uact=5&sclient=gws-wiz-serp&udm=50&fbs=ADc_l-aN0CWEZBOHjofHoaMMDiKp0UJuhqwKhR0QUhF54-6jIZ4fQLFxpd-X3cjBjwn-bveyDdFq6p_1Ihh_Ql-GGwzDrx965YmoBHPdZqjpk_wLcr87EOVDrNef7abUsdy7lRfcH9HduY3ypbiqLxbsL21UWg8kiZoouB9nEp7CN9iwIQTZNErSg2mYdqm_lNuaH6dd_mwj6XsekAu4ZQqdcS9xvsucig&aep=10&ntc=1&mstk=AUtExfCZMemFB51m4S6HuNpB6ZNqrL2MZ9iLPahXcV3f9nftZMz8VEzzsfF-0k2B-q1ClJtpFKAIRs17eCrRjNILMTlVVcVkZxKEKkSoMhND4k9NAAnpyuUD4LpYj0FYBfilE1SzOLm9790fcu7lDVN0EXj4GqfsCsZ4gWiF4lInPSzlkYrVG91NioCgDaQMtGVkmT5DgMkqKzjM6gf9wyLR3ITA6bVj4HTLhWcoHFLcgc6NtdsOzuOvgDfx9jwzswqit5Wm-vtMcmvpe-pBmNjwRnibMNwdPrK5au2jiAlDTHAsX3NbE7ip1N5HIhaT231AxVpgYIQTbV-MGiOCa057HD6O_lwQNMtlvaTR_F7pPSnmk2tr-X0oanP7KbG2ehhxQu1mcgzfpC1lvmY_s41mlOhsLGoCnA6bNQ&csuir=1&mtid=5ZluabyWG7ul5NoP5OeLiQM

Surprised nobody posted the zoomed in version of the AIFS 360 hour map. It's insane and I can't imagine it verifying, but it surely shows the potential of the pattern. Also, I know this is the NYC forum, but I was wondering if anyone had access to the AIFS ZR maps for the southern US at least for the 1/25 storm, which is looking pretty "real" right now. The CMC and Euro are bad enough and if they verify, the ice may be the biggest story with this storm (and if the AIFS is right, it'll likely be close to the CMC ice map as they're close on snowfall for 1/25), but given how good the AIFS has been would love to see that map. TIA.

Odd that they wouldn't have the heavy snow outlook up to at least Philly/SNJ given the NBM map showing 6" up to 276/195.

Since I live at the edge of the Mt. Holly CWA, here's my final post on the storm... We got 2.4" of new snow this evening for a total of 4.1" today and 5.8" over two days, which I'm ecstatic about. Another very pretty snow as it wasn't windy and the snow was wet enough to stick to the trees. Going to finish watching the football game and then go shovel.

Calling it over at 8:45 pm, as the snow became light around 8:20 pm and looks like it'll be just flurries from here on with precip ending shortly, unless there's a surprise. Anyway, we got 2.4" of new snow for a total of 4.1" today and 5.8" over two days, which I'm ecstatic about. Another very pretty snow as it wasn't windy and the snow was wet enough to stick to the trees. Going to finish watching the football game and then go shovel.

7.9" just today?

As of 8:00 pm, still snowing pretty good with 2.2" new snow otg for a total of 3.9" today. Snow looks like it'll end soon, but I think we'll eke out at least another 0.1-0.2" to get to 4". Still 31F.

As of 7:00 pm snowing moderately to almost heavily, up to 1.5" in round 2 (0.5" last hour) and 3.2" overall (my house forecast 36 hours ago was 3.1") and looking at the radar, I think 4" is within reach. Still 31F.

Snow picked back up again finally around 4 pm and we got 1/4" by 5 pm and now at 6 pm it's snowing heavily (see tweet below) with 1.0" new snow on the ground in round 2, bringing today's total to 2.7". Should easily get to 3.5-4" I think. 31F - and make sure you shovel tonight, because everything will freeze solid if you don't overnight with wet snow and lows around 20F (and Thursday may be the only day above 32F this week and even next week). https://x.com/iembot_phi/status/2013016419634380819/photo/1

Just started snowing moderately, so I looked at the radar and saw this! Nice surprise decent band over us. Main 2nd round still arrives after 2-3 pm, but snow like this will at least reduce compaction/melting loss.

As of 10 am the snow has lightened up considerably and we have 1.7" of new snow (1/2" the last hour); likely just on and off light snow for the next 3-4 hours. It's 32F.

As of 9 am, 1.2" new snow at 32F. Looks like another 30-40 minutes of snow to go for this first round as per the radar. Not sure how long the lull will last, but if the HRRR model is to be believed, we won't get much snow from about 10 am to 2 pm, after which snow should pick up again through early evening.

Huge gorgeous dendrites falling now and we got 0.3" the last 1/2 hour with 1.0" new snow otg, as of 8:30 am. Down to 31F. Had some great fun trying to throw snowballs (great packing snow) into my disc golf basket in the backyard - don't quite get that sweet sound you get when you hit the chains with a disc.

As of 8:00 am, we have 0.7" new snow (0.4" the past hour) at 32F and snowing moderately.

Just went for a walk and of 7:00 am we have 0.3" otg at 32F and snowing lightly to moderately. Everything is covered including the roads in our neighborhood. Hoping to overperform vs. my 3.1" forecast for my house yesterday morning. Pretty out there...

The NBM finally caught up to the models, lol. This looks just like the NWS map (not a coincidence). I'll take it.

NWS - Philly finally put out their map. Nice, especially for me, lol.