Roger Smith

2" snow on the ground STL (28/27) ... bring it.

Charlottesville, the snow capital of the eastern United States -- now accepting bus tours from Boston and New York City.

The ensemble of different versions of ECM contain solutions that track further north and mix the precip. If the map you're referring to is accurate, no mixing concerns, would buy ear plugs for the deafening thundersnow.

The ECM shift to a southern track is plausible, and the GFS concept of chain of lows along a front fails to separate the 19th and 21st energy peaks from my research point of view, so if I blend a better separated GFS with this ECM track, I think you are in the hunt for the jackpot that seems inevitable with the 21st energy peak. More chance of it shifting back north than any further south, it is a finely tuned sports car low that the ECM advertises, and 15-30" certainly in its specs, would toss the 40" though, this is not 1888 and western CT.

Mixing may not be that big a problem anywhere north or west of RIC, certainly on the edge there but when the coastal starts taking over, colder air over the Potomac region will slide south and I would envisage the mixing zone being closer to southeast VA as a result. Going with these amounts: Max for storm in axis of CHO-north of EZF to Easton MD, 6-9 inches 4 inch line parallel to that with northward jog around higher terrain, approx IAD-BWI. DCA therefore in a higher snowfall position but will they measure it? No, so amounts all 4.0" (DCA should be 5.5). 2 inch line just around PA-MD border. On the southern edge of snow zone, 4" from RIC to Ocean City MD, extending southwest from RIC towards n/c NC. LYH and ROA about 5"

This weekend snow event cries out for a contest, but I'm not the one to post the thread. Hoping someone will take up the challenge. We'll see who's dividing by what at the end of this business.

I wonder if you'll get the same kind of snowfall that we got here when the Pacific storm ran up against the same wall of arctic high -- I realize this is a different packet of energy than the southern stream in NM-TX but perhaps the air mass interactions will be similar. We had 5.0" of snow over 36 hours and throughout the event the flakes were very small, like drizzle that turned to snow. It kept accumulating at about 0.2" per hour with some lighter intervals. But it looked like a snowstorm throughout. Temp/dew point was about 28/27 for the whole event. No wind so it just sat level and now it's very slowly sinking to about a three inch cover.

Not a burner account for JB, in fact past two days I've been posting 2-4" most likely DCA-BWI and 4-8" central VA. Still thinking that after looking at RGEM and GFS. Frankly, more concerned about a near miss scenario to south than any chance of bigger amounts than those. There was one moment a few days ago where I thought this storm could do much better, but tracking it on radar through NM into TX has convinced me it's a weakling that could grow into a mesomorph -- maybe that's the connection to JB1. (as for Justin Berk, who I now see is an actual person and not a fun name for Joe B, well, I never heard of him before today. And I don't even know where Owings Mills is located although I'm guessing it's north of a lot of other places?). Anyway, the divide by 3 rule seems to have shrunk down to divide by 2 at this point.

Dr Maybe said maybe, some of these GFS ensemble members spin up huge amounts of snow out of a very uninspiring looking pattern, what's with number five, thunder-snow or whatever gets the amount up so quickly ... not realistic looking at all ... I hope for the best but would go with 2-4" for now, slightly heavier to south, and all eyes on days 10-11 (full moon is 21st so not surprising to me that a larger event shows up then). I don't see much of a 1993 in it, more like 1899 perhaps.

That was by no means the first time.

The three best features (to balance out all the obvious risks that argue for low outcomes) -- (a) very warm offshore SST values near 24 C east of southern Delmarva -- should energize the low on Sunday and provide higher moisture contents in frontal bands (b) linking up of main arctic high in SK to very cold western slug now close to n AB s NWT border (-42 C) -- will produce a conveyor belt effect for double-centered low (c) energy peak well positioned and timed to impact storm development 12z 13th ... so blending that into what might otherwise be an anemic system, should cancel out some of the negatives and result in a moderate outcome, hence the 4-7" call. But yes, I would divide that by three if a solution like the GEM verified. OTOH would double the 4-7 if this gets some muscles and lifts like the five outlier solutions mentioned.

Shouldn't that be 2.54?

4 to 7 inches for most, 7 to 10 locally central VA to s/c MD ... needs to lift off the runway a bit based on current consensus, to improve to 7 to 12 inch event for most ... nice frontal energy visible west of s CA on satellite, hoping this invigorates the situation over n Mexico then Texas by Friday morning. GEM looks too suppressed at this point, GFS at least brings low center inland over southeast and closer to se VA. ... optimistic that later guidance will improve, this is a very cold arctic high forming over nw Canada trailing the main center in SK and models may be underplaying low thickness field likely to extend through western portions of the ridge to north of storm. This would translate into more hangback energy and snowfall.

Snowfall contest 2018-2019 ... updates through Jan 31st ... forecasts marked in red have been passed by actual snowfall. FORECASTER ___________ DCA _ NYC _ BOS __ ORD _ DTW _ BUF ___ DEN _ SEA _ BTV Snowfall to date ________ 12.9 __ 7.5 __ 2.3 ___32.3 __21.4 __91.0___14.4 __ 0.0 __69.3 RJay __________________33.0 _54.0 _ 70.0 __ 30.0 _ 38.0 _100.0___ 65.0 __ 6.0 _100.0 DonSutherland.1 ________ 32.5 _ 50.0 _ 57.5 __ 48.5 _ 53.5 _110.0___ 52.0 __ 3.5 _ 93.0 Tom __________________ 26.3 _ 56.4_ 65.6 __ 29.6 _ 41.6 _ 95.2 ___ 62.3 __ 1.9 _ 89.6 wxallannj ______________ 25.0 _ 47.0 _ 52.0 __ 49.0 _ 51.0 _ 83.0 ___ 57.0 _ 13.0_ 77.0 Scotty Lightning _________25.0 _ 42.0 _ 75.0__ 70.0_ 80.0_120.0___75.0 _ 10.0 _ 85.0 BKViking _______________24.0 _ 55.0 _ 71.0 __ 35.0 _ 39.0 _ 78.0 ___ 60.0 _ 18.0 _ 78.0 ___ Consensus _________ 24.0 _ 44.5 _ 60.9 __ 37.5 _ 44.7 _ 92.6 ___ 58.5 __ 6.4 _ 88.8 ___ Consensus dep _____ +11.1_+37.0_+58.6__+5.2_+23.3_+1.6 ___+44.1 _+6.4_ +19.5 dmillz25 _______________ 24.0 _ 53.0 _ 67.0 __ 40.0 _ 37.7 _ 85.0 ___ 57.0 __ 5.0 _ 90.0 wxdude64 _____________ 22.9 _ 40.6 _ 59.7 __ 38.9 _ 45.9 _ 98.4 ___ 67.6 __ 6.7 _ 90.3 hudsonvalley21 _________ 22.0 _ 40.0 _ 62.0 __ 36.0 _ 48.2 _101.5___ 51.0 __ 5.7 _ 88.0 Roger Smith ____________18.0 _ 28.0 _ 45.0 __ 30.5 _ 35.5 _ 90.0 ___ 60.5 _ 10.0 _ 78.0 Stebo _________________ 13.2 _ 34.3 _ 53.5 __ 33.5 _ 47.0 _ 87.0 ___ 37.0 _ 10.7 _ 97.0 RodneyS _______________12.5 _ 25.0 _ 37.5 __ 41.0 _ 43.5 _ 89.0 ___ 52.5 __ 4.5 _ 73.0 _____________________________________________________________________ High forecasts in bold, low forecasts in italic. Consensus is median, average of 6th and 7th ranked forecasts. Normal will be added later from NWS daily climate data snowfalls late in season. ... watch for updates to season totals and this post will migrate to new months as we move along .

Do you mean SSTs day after departure? I don't see any forecasts of them but would they not likely fall gradually with the wind more northerly? I am using the CMC map as the NOAA maps are disabled due to the government shutdown. The reading east of ACY is unusually high, trending to more normal near HAT and colder than average well out into the Gulf stream off NC-SC. In other words, best cyclogenesis potential is east of the Delmarva.

I see potential for this to deepen rapidly near or just east of ORF. The offshore SST values have a +5 anomaly (recent reports of 24 C) as far north as 38 N. Energy rotating around a system not programmed into models will peak around 13th 12z and I think this will happen near ORF. Models have probably diagnosed 50% of this energy as it has roughly a six-day life cycle. Looking at Euro, despite good potential on that model, surface pressures are currently 5 mb higher in central Yukon and this suggests to me that slug of cold air at west end of linked ridge will be very suppressive, meaning that hangback will be squeezed into banding structure dragged along behind bombing offshore low. GFS seems on a good track, GEM has lost the plot with that southward shift of the primary which I think does not fit the uppers very well; the earlier GEM is therefore preferable. This could all add up to 10-15" snowfall event for your region. Mild air flowing off Atlantic north of primary will probably tighten the frontal bands and reposition the heaviest QPF closer to DCA-BWI than now shown on consensus guidance. Arctic front likely to be just south of Potomac estuary to Ocean City MD. Admittedly, system has a long way to go to develop from modest origins, it is almost detached from Pacific low already (cloud streaks west of Baja) and various things could go wrong, but if the models are on the right track, then I only see upside potential as that energy peak rotates into prime position on Sunday early morning. Northern extent of snow for other forums looking in, I would say roughly ABE-ALB-BGR but with some patchy 1-3" amounts further north from phasing subarctic vorticity.

-42 C at Mayo, Yukon where this arctic high is building up (1037 mbs). I like the looks of this set-up, might be worth comparing to Feb 1983 (El Nino winter, arctic high on similar track) as to potential storm dynamics. Nice energy peak at 12z 13th is indicated. Hoping for the best, want to see 00z model runs before speculating about amounts.

wake up

Maybe 1978 is their analogue then. The lunar dates in 1978 were only 3 days later than in 2019. That means an analogue to the east coast blizzard would occur around Feb 3-4. The Great Lakes superstorm timing would be Jan 22-23. If that was the analogue in play. (for me it's not in play for other reasons) ... When did DC region have a snowstorm midway from new moon to full moon in January? That might provide a clue as to the analogue year (new moon was 6th, full moon is 21st using z time, both back up to near end of previous day using EST to 5th and 20th). I know it wouldn't be 1996 as that storm was just a day or two after full moon.

Looks to me that the "warm core of winter" concept has come and almost gone now, both start and finish a bit ahead of my predicted schedule (I had derived Jan 5-15 for the warm core from my analogues), mid-December to the 10th of January would have been a perfect fit. From Dec 13th to Jan 8th (27 days) the mean temperature at DCA has been nearly 8 deg above normal. There will be a 31-day interval from perhaps 11th to 10th that runs 7 deg above, quite a large "monthly" anomaly but the calendar months will both be considerably smaller (December was +3.2). The warmest part of that was probably back around the Dec 21-22 event that was supposed to have been an east coast winter storm (turned out further inland and too mild). As I concluded in a discussion with some other forecasters elsewhere on this forum, the "torch" was a bit subdued being more of Pacific than Gulf origins, although looking at DCA actual data, it has been a very mild 25 day period that, had it overlapped a month on the calendar, might be causing more chatter in weather circles. Not every warm or cold spell gets equally recalled because of what I call the tyranny of the calendar (for a good example, see late February into early March of 1950, as cold as Jan 1950 was mild, but spread out in parts of two different months). But I am reasonably happy with the pattern compared to the forecast, the El Nino has been its usual self in some ways but is clearly meeting with a lot of resistance from the early invigoration of the arctic this past few months, and Quebec has been the favored ground for arctic highs to reside longest. We should be moving into a much better pattern now for winter synoptics and so I would be looking at dates around Jan 19-21, Feb 3-5 and Feb 14-19 (by then likely two peaks) as best opportunities, although I'm hoping this Jan 12-13 event works out well for the MA crew. I still expect at least near-normal snowfalls in many locations despite the very sparse amounts to date. And with a warm March in the forecast, it implies that I am predicting a snowy late January and February. .

First report on anomalies and forecasts ... ______________________ DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA _8th ___ (7d) __________+10.2_ +7.1_ +7.6 _+12.0_+12.5 _+1.8 __+2.7 _--6.2 _+2.7 _8th ___ (p14d) _________+4.5_ +2.5_ +2.8 _ +6.0 _ +5.8 _+2.0 __ +5.0 _--1.6 _+2.5 _8th ___ (p24d) _________+1.5_ +0.5_ +0.5 _ +2.0 _ +2.0 _+2.0 __ +1.5 _--2.0 _+1.5

Feb 3rd 2019.

It would seem that we have the full turnout now, so here's the table of forecasts for January ... no late penalties which is a nice thing ... Table of forecasts for January, 2019 FORECASTER _____________ DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA RodneyS _________________+3.2 _+3.5 _+2.8 __ +4.9 _+3.4 _+2.2 ___ +1.9 _--1.5 _+0.4 wxallannj ________________ +2.2 _+1.8 _+1.3 __ +2.2 _+2.4 _+0.6 ___+1.4 _+0.3 _+1.3 RJay ____________________ +2.0 _+2.0 _+2.0 __ +1.5 _+1.5 _+1.0 ___+1.0 _--0.5 _--0.5 Scotty Lightning ___________ +1.5 _+1.0 _+0.5 __ +0.5 _+1.5 _+1.5 ____0.0 _+0.5 __0.0 wxdude64 ________________ +1.4 _+1.1 _+0.8 __ --0.2 _--0.4 _--0.2 ___+1.2 _+0.4 _--0.4 Roger Smith ______________ +1.2 _+1.3 _+1.5 __ +2.0 _--0.3 _--0.5 ___ +1.5 _+0.5 _+1.8 ___ Consensus ____________ +1.2 _+1.1 _+0.8 __ +1.5 _+0.4 _--0.1 ___ +1.1 _+0.3 _+0.4 Stebo ____________________+1.2 _+1.3 _+1.5 __ +1.7 _--0.5 _--1.2 ___ +0.7 _--1.3 _--1.5 hudsonvalley21 ____________+0.9 _+0.5 _+0.3 __ +1.2 _+0.4 _--0.1 ___ +1.4 _--0.3 _+1.0 BKViking _________________ +0.8 _+0.6 _+0.6 __ +1.0 _--0.2 _--1.0 ___ +1.1 _--1.0 _--0.3 DonSutherland.1 ___________+0.8 _--0.4 _--0.6 __ +2.5 _+1.4 _--0.3 ___ +2.0 _+0.5 _+4.1 ___ Normal ________________ 0.0 __ 0.0 __0.0 ___ 0.0 __ 0.0 __0.0 ____ 0.0 __ 0.0 __ 0.0 Tom _____________________--1.5 _--1.1 _--1.2 __ --2.5 _--3.5 _+0.5 ___ +0.1 _+0.3 _+1.1 _______________________________________________________________________ warmest and coldest forecasts are color coded. Normal also joint coldest for DEN.

I suspect we will have a very active season with at least one major outbreak. Predicting 1520 tornados. First max risk will be around April 9-10.

For the first tie-breaker (let's face it, these never will be breaking any ties, but just add three more elements to the contest) ... ORD managed the scanty total of 1.4" with a late surge out of deepest futility, and that came not that near even our lowest forecast, so the lower you went, the more ties you can break. Our best effort was 3.6" by vpBob21, then 4.1" from Mississauga Snow and 4.5" from Jackstraw. Our average was 7.9". The amounts have been updated in the post dated Dec 17th (edited to Jan 1st). Not much snow was reported since the November snowfall event anywhere in the contest grid except for MQT, APN and GRB.