jwilson

Not ready to buy into an idea of sustained winter return just yet. We might get intermittent cold shots, but on the ensembles it still looks quite brief, and even the long-range GFS/Euro have tempered the cold look for next weekend. A couple days of high 30s spread apart. EPS and GEPS are generally warmer outside the northern plains. GEFS shows a more matriculating cold into the east, but that's at the very end of the run, so the potential length is unknown. +AO and +NAO look persistent. -PNA, as well. MJO into Phase 5 is what I'd call "tempered" or neutral in March, but Phase 6 is straight warm. Magnitude dependent. Seems like a more balanced or oscillating pattern - no full torch or deep winter. Maybe later in the month things move definitively, either way.

Ensembles look mostly warm through the period, maybe a brief shot of cold in between (say a weekend). Can't say I'm disappointed. I'll be the deb here, but I'm over the nickel-and-dime events by this point. If it's going to snow anymore, it has to snow. This is about as wall-to-wall winter as we're likely to get, though, so I'm fine with an earlier spring. As it is, we look to finish with another below-average February snowfall - five in a row. Last time that happened was 1998 to 2002. Then February 2003 happened. Could we see a similar result next year in a Nino?

More or less, yes. Like 1996 (which I guess wasn't a big impact for Pittsburgh but remains my personal biggest snow). Some storms are hybrids that have multiple components. I've experienced both, but I find that oftentimes with the dynamic nor'easter bombs, you spend a lot of time sitting in subsidence with terrible snow growth and have to wait for decent bands to rotate over you. It's a massive win if you can get training of bands in the same spot, but that's even more rare. See with this storm and the isolated jackpots in SE Mass and Rhode Island, maybe some along the coast in New Jersey or Long Island. Obviously, you'd almost always take the big-time rates under those bands, but they're just unreliable and limit the big totals to relatively narrow zones. Also, as has been said, Pittsburgh is too far from the Ocean to experience the entire "Miller B" playlist. November 1950 storms don't grow on trees.

Intense snow for some, subsidence for others. That's the tough part of those bombogenesis coastals. You can experience some really intense moments, but for my money, overrunning into a cold-air block is the preferred method of snow generation. Big, widespread totals with less dependence on a locality under extreme convection.

Storm totals remind me of those events in 2009/10, only cut East to West instead of South to North. Experienced some rough gradients back then. Subsidence next to the primary convection is unforgiving. Also, I've noticed Mt. Holly tends to have an underlying tendency towards aggressive forecasting, and I say that as someone that doesn't live in the CWA full-time, anymore. I think that's just their forecasting philosophy or preference.

I'd chase this one if I wasn't sick. Can't believe the Goofus might actually get one right this season.

Might have to enjoy next week as the last week of winter. I think the Sunday event is mostly a coastal, either way - scrape or out-to-sea. Doesn't appear to have a lot of intrigue for our area. I can see one or two other snow chances. Nothing major yet. Incoming March pattern looks like straight-up pacific firehose of warmth for most of the CONUS. I'm more of a November and December snow guy, truthfully. March is often a wildcard, but if I had to choose, I'd take early season wins over late ones. Our bigger March snows seem to pop every five years on average. Next year would be five years since a healthier March snow total (17.1" in 2022). The pattern can always flip colder mid-or-late March, but by then you're asking a lot for true snow events.

While it has been a fairly cold and snowy winter, overall, especially relative to recent history, we haven't totally escaped warm spells. December was 40F+ between the 17th and 29th, including those final two days of 64F. January also had a warm burst, though shorter in duration, between the 5th and 14th. Not that anyone would remember now, haha. We're definitely losing the favorable meta-factors. All indices look to flip: -PNA, +AO, and +NAO. EPO region looks to go back to positive, as well. In fact, it looks like a lot like that December alignment. In that sense, we could, in theory, look at a two-week period (give or take) of generally warmer temps. The timing of that is unfortunate because we'd be losing some of the prime winter portions in the heart of February, our second-snowiest month, on average. The remaining question is if the pattern reloads again come March, or if we slide into an even warmer pattern long-term. I think the former is more likely, as we've seen multiple times already this year, but that is always TBD.

1-2" is the general idea for tomorrow. NBM mean is 1.4" at PIT and 1.1" at AGC with decent enough odds of >1" (70%+). Only takes 0.1" at 10:1 to get an inch, so we don't need a ton of moisture with even better ratios. Could be between 15:1 and 20:1, give or take. Latest NAM and GFS are both ~2" according to BUFKIT. Next weekend still a ways out. Nothing really interesting on the operationals. Cutters and other sheared-out messes. Ensembles have also lost a bit of the signal, so I think odds are against anything relevant for now. It will likely change.

Imagine losing Stoutland and Fangio in the same offseason. Thank goodness Fangio decided to stay another year. Sounds like last year's dysfunction got to Stoutland, though, which is extremely disappointing. What a waste.

Not that I enjoy refuting Schwartz here, but wasn't the -AO from 2009/10 winter much more sustained, overall? It averaged -3.4 in December, -2.6 in January, and -4.3 in February. The AO actually had a positive average this past December. January is clearly going to be negative, and I'd guess February is, too, but it's flowing positive in the short-term and the rest of the month is TBD. Even in 12/13, there were negative AO departures from October to March.

As RitualOfTheTrout has said, we're going to enter a relaxation period with the AO shooting back toward positive, the PNA coming down toward -1, and the NAO block relaxing, as well. Looks like my transition period storm isn't quite evident, at least not yet. We'll see if anything pops up before midweek aside from the clippers. There's another potential threat around Valentine's/President's Day weekend. Everything remains in flux after President's Day. The AO hints at going right back down, but the long-range MJO might enter hostile territory (warm phases). The ensembles do show another warm-up after President's Day. I would guess it is only temporary, if it happens at all. Long-range warm looks have failed this winter, but the pattern will reshuffle and might wobble until something takes over.

I like the moves in tandem because to me, they signal an organization that knows what is wrong and is trying more elaborate methods to fix it. A retread OC with more experience might have more immediate value for a team that wants to contend, but this move has more upside, IMHO. Higher risk, higher reward type of deal. It seemed like a good process to get here. Lurie and Howie have a good track record, in this regard. I also didn't think any of the experienced OC's to hire were all that intriguing.

We might get a few light snows in between, but I think the next period to watch for something more interesting is that Sunday-Tuesday timeframe, Feb 8-10. Some models have teased an event. I've seen some favorable looks, but nothing incredibly consistent yet. A few things to watch. Another neutral slide in the PNA around that time. Long-range hints at a 50/50 and -NAO. Ridge placement could be ideal. Maybe more chances with the -AO remaining quite negative. Not even sure yet when this pattern is keyed to break down.

Weekend threat is a wave spacing issue, it looks to me. There's not enough separation with the elongated energy at the front-end (the main lobe), and the backside piece of energy isn't phasing in to the main pool. In bigger storms with this kind of arrangement, you'd typically see the stretched lobe break off into two pieces, and the backside piece would phase with other energy while the other piece out front acts as a block. It was always an extremely delicate setup. Probably not worth investing in unless we're <48 hours and getting consistent results. Likewise hard to predict because there's so much energy flying around.

Differences between 6Z Euro-AI and 12Z Euro-AI were very subtle. If you look at 12Z, the backside energy isn't getting phased into the storm as quickly. At 6Z, that energy was almost immediately getting pulled into the mix. I think that has to do with spacing between the waves and the elongation of the lobe itself. If it is more stretched, it is closer to the backside energy and more likely to phase the two. A more condensed lobe separates and moves too far east. Ridge position looks nearly identical to me.

I measured another 3" since noon, which includes the half inch I got while shoveling. Rates were back up over an inch an hour, but the dryslot looms until the upper level trough passes through later. That's somewhere between 7.5" and 12" total. We might be able to manage a foot if the backside lasts long enough. Haven't hit that mark since December of 2020.

Too bad we couldn't pair a system like this with some kind of blocking upstream. This would have been a true big dog in that instance, but someone on the northern edge would have gotten fringed. Blocking has been the hardest thing to come by in the last ten years, though. Maybe have to wait for an El Nino return, or we could get surprised again this year. We're on the front end of this pattern. There may be more chances in the next few weeks.

Lull coming into the city proper now. Looks like Youngstown area might be the big winners. Persistent banding up there. Outside of NE and central PA locations.

Lots of sleet signatures down in Greene County, WV panhandle. Hopefully that northern progression ceases. Our snow growth has clearly diminished for now. Pixie dust.

Couldn't keep up with the snow shoveling. Inch an hour rates if not more. I measured between 4.5" and 9" so total somewhere between there, lol. Snow is drifting quite a bit because of the powder consistency.

I do think this one has some overperforming potential. It will be an interesting case study when it's all over with, and we can review how the microclimate handles these two intense competing forces. I could see things going both ways, truthfully, so good luck to everyone and may your snow stay powder.

Checking short-term trends, proclivity is more QPF which also comes with higher chance of warm layers. I think I stick with my call from earlier this AM and hope for an overperformance and minimal sleet/ZR. NBM did increase odds of >18" from 4% to 11% at AGC, but shows more pronounced chance of mix during a brief period. I wonder how the NBM accumulation products account for mixes and ratios with inconsistent output across models. Hard to say. Also, if you check NAM runs from yesterday, they didn't have zero snow at Little Rock. The thermal profile was maybe off but it did show like 3-6" of accumulation by noon today on near every run as far as I can tell. No idea what that person is looking at.

NBM is finally working again. Average precip on the 1 UTC run is 0.88" equating to a mean of 11.4" of snow. Spread is 11 to 15 between Saturday and Sunday. 70% chance of >12", 96% chance of >8" (which is somewhat nutty). That's all at PIT; odds are slightly better at AGC, actually, because of the presumably better rates. 74% and 97%, respectively. Non-snow peak odds are later on Sunday at 11% chance of rain compared to 78% chance of snow. I'm guessing that's picked up mostly by the group of mesos that are showing a warm tongue/small dry slot. I still don't like how close the primary comes to our area. Typically, when that does happen, we change over south of the city. The thermal profiles on all the models check out, but I guess it depends how much you trust them to handle the microclimate. Bufkits for NAM and GFS are all snow at AGC. Between 10" and 13" depending on the run. Ratios aren't great, so any improvement there means more accumulation. 0Z NAM actually barely gets above 10:1 the entire duration. Max is 12:1 except for a brief period of 21:1 at the tail end on 1.33" of QPF (high). That's why storm total is "only" twelve inches. If I had to do a first call, I'd probably go a little conservative on the southern regions of Allegheny, Washington, Greene, and Fayette (Mon Valley): 8" to 14" - 6" to 8" at MGW, less points south - 10" to 14" city points north. Any mesoscale banding that takes place has a significant impact on localized totals because of convergence and associated divergence. Could see lollipops of 16" somewhere in the coverage area. It's arguably low for city-south, but perhaps I'm paranoid. Too many years in MGW. I might adjust that upward tomorrow as more mesos come into confidence range. I think closer to the 8" figure if there's mix/sleet, closer to 14" if there's a clean hit. I still don't necessarily trust the models on thermals assuming the northern progression of the primary low is correct. I'll revisit this thought after the storm. Anyway, just my word vomit. It's 3 AM, give me a break!

NAM says 10 PM give or take an hour, and logs an inch by 3 AM. GFS holds back a bit more and says up to an inch at 5 AM. Starts around the same time but then takes a two-hour break. These according to Bufkit data. I'd imagine the best rates are early Sunday and then maybe again overnight into Monday. We'll get a better idea with the higher resolution models, as has been mentioned.