RU848789

Hey @SACRUS - always loved this resource, but looks like a lot of links don't work anymore (most of the radars)...

It's fascinating really: we have we have the Euro/GFS (snowy) vs. CMC/UK (snow/sleet) on the globals and HRRR (snowy) vs. NAM (snow/sleet) on the mesoscale models - almost 50/50 to me. Anyway, 18Z HRRR ftw! Or 18Z NAM for the...sleet, I guess (still way better than rain) - posted both the Pivotal/Tidbits maps so people could see the difference (sleet counted as snow by TT, which is ok if one uses both, as per below). Also, I've posted about sleet in models and sleet impact in depth before, but worth a repost, IMO (this is from last night, elsewhere, but applies still). Briefly, Pivotal only reports pure snow and TT reports snow + sleet, but all counted as snow. One can't figure out how much of the TT frozen equivalent is snow vs. sleet directly, but you can if you compare the Pivotal and TT maps, as long as you use the 10:1, snow:liquid outputs. Pick a spot like Philly, which shows 4.4" of snow on Pivotal and 13.4" of "snow" on TT. Since both are reporting the amount as 10:1 that means the Pivotal LE is 0.44", while the TT LE is 1.34". If you then subtract out the snow from Pivotal from the TT total, that means that 0.90" of that LE is sleet and if one assumes that the sleet has a snow:liquid ratio of 3:1, then that is 2.70" of sleet by depth. In theory, that that 4.4" of 10:1 snow and the 2.70" of 3:1 sleet would equal 7.1" on the ground, but often sleet falling on top of snow will compact the far less dense snow underneath it (I measured that effect in the linked post) by 25-50%, so one might get a snow/sleet depth of 5-6" and not 7.1". The opposite is not true, i.e., snow falling on top of sleet will not change the depth of the sleet, so you'd see 7.1" on the ground for this case. Given my long history in emergency preparedness, including being in charge of snow removal crews for the site where I worked for 30+ years (5000 person site in Rahway - Merck), that's why I like the TT maps better from that perspective, since frozen mass and not depth is far more important with regard to plowing/shoveling/snow removal, as well as with regard to impacts on the road, meaning 1.34" of frozen LE mass is just as impactful whether it's 13.4" of 10:1 snow or 4.5" of 3:1 sleet or anything in-between. The one exception to this is visibility, as sleet barely affects visibility. That's why, to me, the Pivotal map of 4.4" does not tell me at all what the impact really is going to be, while the 13.4" of "snow" (which is really a snow/sleet mix) from TT tells me what the impact will be. I get the aesthetics part of it, but from a meteorology perspective, since so much is based on preparing the public for impacts, I've always been surprised and disappointed that mets don't report total frozen mass at least alongside frozen depth. Maybe more than folks bargained for, lol, but hope it's useful.

Started snowing lightly here around 2:40 pm - nice dusting...Will be on the knife's edge late this evening into Thursday on whether we get sleet and how much - will possibly be the difference between 6" snow/2" sleet vs. 12" snow (same frozen mass though!) - I'm fine with either - the thing I hate is rain in a winter storm.

Just posted elsewhere that we need to see if this is "real" or not vs. the other models, i.e., whether there's some heretofore unseen parameter leading to all models trending this way or if it's just some flaw in the data input or model physics with the NAM. We'll know in a couple of hours. Just like one shouldn't overreact to a huge jump up in snowfall for one model (like the 40" RGEM the other day), one shouldn't overreact to one model slashing snowfall. Also, at this point, the NAM is often pretty good, so even if it's an outlier it can't be discounted. As I said this morning, I did think Mt. Holly was too bullish on total snowfall, especially for the 95 corridor (12-18") and NWS-NYC was likely a better call with 8-14" of snow/sleet for NYC/95 corridor.

NWS just put out their regional snowfall map, below, and the NWS-Philly is staying fairly aggressive - a bit moreso than me, with 12-18" of snow (with some sleet) predicted for most of Middlesex, Mercer, Somerset, Bucks, Montgomery, Chester, Delaware and Philadelphia counties and all of Somerset, Hunterdon, and Morris and even a bit more than that NW of there with 20-24" predicted for the Poconos, Sussex/Warren, and Lehigh Valley.Warnings are up for all of these counties and watches, still for the counties on the NJ side of the Delaware in SNJ, and Monmouth, since sleet/rain may hold accumulations down there. Monmouth might see the biggest gradient of any county, with only a few inches along the coast but possibly 12" or more close to Middlesex and Mercer counties.And the NWS-NYC is similarly aggressive with 12-17" predicted for NE NJ (Union up to Bergen) and the Hudson Valley and CT, but a little less aggressive with only 8-14" for NYC and most of LI, as they think sleet will hold accumulations down a bit - this is what I would expect for Middlesex, Mercer, Philly and its close suburbs in PA. It's why my guess for my house in Metuchen is for 14" of snow/sleet (the point/click forecast is for 17" in case anyone thinks I'm bullish, lol).The NWS also put out their regional max wind gust map, below, and it shows the coastal counties in NJ/NY with up to 60 mph gusts possible and 40-50 mph inland (this would be mostly after 11 pm Wednesday, through 7 am Thursday). Where this coincides with heavy snowfall, we'll likely see occasional blizzard conditions, although my guess is we'll only see blizzard warnings for LI and maybe NYC.https://www.weather.gov/erh/gis_wfo?id=PHI

Pretty happy with 12Z. My thoughts, for what they're worth... Basically, the Euro, UK and CMC all moved a bit SE with their snow fields, as the confluence was a bit stronger, so the track of the low was a bit further SE, meaning the snow/rain (or snow/sleet) lines moved SE a bit (like 10-20 miles, which isn't a lot, but makes a big difference for some), more towards what the GFS had been showing - and the GFS moved significantly further NW with its track and snow field, meaning the models are closer together than they were the last 2 cycles, but still some differences obviously. Models should in theory converge as one gets closer to an event (every model will show almost the exact same forecast 1 hr into the future), though, but good to see. If you live along or NW of the 95 corridor, prepare for a major (8" or more) snowstorm, with 12" or more possible especially just NW of 95 and anywhere NW of there. Just SE of 95 and towards the coast will likely be the battleground for snow/sleet/rain at times. Also by early Thursday, after about 1 am, most folks should be snowing and the winds will increase to blizzard levels, so it should be pretty wild from maybe 1 am to 7 am. Let's hope for no nasty surprises on this one, especially after last year's fiasco. I think we're good, though, unless you're at the NJ coast and even they'll likely still have some fun on the backend. NWS has 15" at my house - that's about my thinking too. Make it so, lol

Of course the UK is far, far worse than any other model for those SE of 95, with basically only 1-2" from DC to Philly to Asbury Park, whereas 10 miles NW of that line gets 10" and 20 miles NW gets over 15". I can't see the gradient being that steep, but stranger things have happened I guess. Are those locations showing very little snow getting sleet at least? Hard to believe the snow to rain cutoff is that sharp for the whole storm. I'd get incredibly lucky in the Edison area with 18" of snow, while friends 15 miles SE of me in Holmdel would get maybe 3-5" and folks 10-15 miles SE of there would get nada.

That's what the NWS has been saying, given thermal profiles of the column...

D'oh! Fixed it, thanks - sleepy time, lol...

In case people haven't seen the UK - I'll take two please. I assume the Euro will join the GFS/CMC/UK in keeping us in loads of digital snow.

Meh, I'll take it, lol...(have to subtract Monday's few inches of snow from this, along/NW of 95).

Make that GFS/CMC/UK/Euro consensus. Boom! Euro also shows 1-3" along 95 and 3-5" NW of 95 in NJ/EPA/SENY on Monday.

Not sure I can recall such model consensus 5-days out from the GFS/CMC/UK for a major winter storm for the Philly-NYC region. I assume the Euro will still show such a storm too. Let's hope this one isn't only a digital snowstorm.

And it's in the 20s for the 95 corridor and NW of there with temps only getting to 32F at the immediate coast. Would be nice to have enough cold air to not have to worry about p-type...

Just my opinion, but I think we need two separate threads for the 14th and 16th potential events. Way too many posts in this thread where it's difficult to tell which event someone is talking about.

I know it's just one model run and it's 8 days out, but there's at least hope - I could live with this in CNJ (GFS/CMC show snow N of 84).

Interesting to see the moderate weakening observed by the hurricane hunters this evening with winds now down to 130 mph (just barely Cat 4). However, in the last hour or so, there have been indications of an eye trying to form, which is often a sign of intensification. The Yucatan could use a break, although 130 mph is still a big deal. Beyond there, no real change as the forecast is still for a Cat 3 hurricane to strike the central LA coast Friday night (120-125 mph) - the center of the track has landfall near Marsh Island, just south of Lafeyette and about 100 miles west of New Orleans and 90 miles east of Lake Charles. Let's see if tonight's models make any big moves on track or intensity.

You can close the thread after this post, lol - this really cracked me up - you could use the same meme for the small asteroid that might hit us the day before election day... https://www.cnn.com/2020/08/22/us/asteroid-earth-november-2020-scn-trnd/index.html

Surprised so low, when we got 2.75" just 5-6 miles away and New Brunswick got 2.55".

A general 2-4" for most of NJ and nearby DE, SE PA, SE NY, with lollipops to 6" in parts of SWNJ and CNJ so far. Pretty impressive. Got 2.75" at our house in Metuchen with 90% of that between about 12-3 pm and only some occasional showers since then.

Are you calling me nobody, lol? I did post a summary of everything around 4 am - didn't post before that since there was no activity...

Great stuff - is there a link to this? NWS is so cryptic with its info that things like this are hard to find...

Earlier today, when the NHC was forecasting 3-5" for rain for most of the mid-Atlantic/NE (with up to 8" in spots), I was skeptical, since the 12Z models almost all showed 1-3" of rain, mostly, and the NWS offices (Philly and NYC) at 4 pm were calling for a general 1-3" of rain (with locally greater amounts) for the Philly-NJ-NYC-CT-LI region. However, if anyone has looked at the 0Z suite, every major global (Euro, UK, GFS, UK, and CMC), the NAM, the RGEM and even the HRRR are all showing at least 1-3" of rain" with the UK, Euro and CMC having significant swaths of 3-5" of rain for this area with some lollipops over 6" on a couple of models. That's flooding level rains in 18 hours. I'm not a rain fan, so I have no interest in seeing that much. Too sleepy to post all the maps, but it's a pretty accurate take, I think. Here's the latest from the NHC at 11 pm: Tropical Storm Fay Discussion Number 2 NWS National Hurricane Center Miami FL AL062020 1100 PM EDT Thu Jul 09 2020 Key Messages: 1. Fay is expected to produce 3 to 5 inches of rain with isolated totals of 8 inches along and near the track across the mid-Atlantic states into southeast New York and southern New England. These rains may result in flash flooding where the heaviest amounts occur. Widespread river flooding is not expected at this time. 2. Tropical storm conditionsare expected along portions of the mid-Atlantic and northeast coast Friday and Friday night, and a Tropical Storm Warning is in effect for the coasts of New Jersey, New York and Connecticut, including Long Island. FORECAST POSITIONS AND MAX WINDS INIT 10/0300Z 36.3N 74.8W 40 KT 45 MPH 12H 10/1200Z 37.7N 74.6W 45 KT 50 MPH 24H 11/0000Z 39.9N 74.1W 45 KT 50 MPH 36H 11/1200Z 43.0N 73.3W 30 KT 35 MPH...INLAND 48H 12/0000Z 46.7N 71.7W 25 KT 30 MPH...INLAND 60H 12/1200Z 50.2N 69.3W 25 KT 30 MPH...POST-TROP/EXTRATROP 72H 13/0000Z...DISSIPATED

Sea surface temps are pretty marginal N of NC, though, so doubt we'll see a strong storm anywhere near us (doesn't mean we can't have very heavy rains though, with the right track - just talking winds/coastal flooding perspective). Also, not sure how "tropical" this system will really be.

Two camps in the 0Z suite. Camp 1 shows about 2-4" of rain for most of the Philly-NYC corridor (and points within 50-75 miles of 95) on the GFS and NAM with the low coming right up along the coast, while camp 2 has 1/2-1" of rain on the Euro (which was showing 2-4" of rain for the area in its previous two runs) UK, and CMC (less well inland, with the 1" amounts at the coast) with the track 100+ miles offshore, for what it's worth. More tracking on tap...