Roger Smith

Managed to find a list of co-op snowfall reports, the highest I spotted in MI was at a place called Mancelona which is a few miles northeast of TVC, and they report 26 inches with a base of 24" ... GRR had reported a total of about 17 inches 22nd-24th so far.

Yesterday as reported in the storm thread, NYC set a new record of 50 F deg for daily range (max 58, min 8). Today another record is now confirmed. The high of 15 at NYC establishes a new record temperature fall for maximum dailies, day to day as shown below: _ Rank ___ Dates _______________ From _ To ___ diff _ 01 ____ 2022 Dec 23-24 ______ 58 __ 15 ____-43 _ 02 _____1918 Feb 20-21 ________59 __ 18 ____-41 _ 03 ____ 1921 Mar 28-29 _______82 __ 42 ___ -40 _ 04 ____ 1927 Dec 8 - 9 ________65 __ 26 ___ -39 _ 05 ____ 1915 Apr 26-27 _______ 92 __ 54 ___ -38 _t06 ____ 1896 Feb 16-17 _______ 44 ___ 7 ___ -37 _t06 ____ 1978 Jan 9-10 ________ 58 __ 21 ___ -37 _t06 ____ 2003 Apr 16-17 _______ 88 __ 51 ___ -37 _t09 ____ 1876 Jan 10-11 ________60 __ 24 ___ -36 _t09 ____ 1911 Nov 12-13 ________69 __ 33 ___ -36 _t09 ____ 1933 Feb 8 - 9 ________ 60 __ 24 ___ -36 _t09 ____ 1970 Feb 3 - 4 _________56 __ 20 ___ -36 _t09 ____ 2014 Jan 6 - 7 ________ 55 __ 19 ____ -36 _t14 ____ 1890 Feb 5 - 6 ________ 68 __ 33 ____ -35 _t14 ___1898 Dec 31-1899 Jan 1_ 53 __ 18 ____ -35 _t14 ____ 1918 Jan 12-13 _________53 __ 18 ____ -35 _t14 ____ 1934 Mar 18-19 ________71 __ 36 ____ -35 _t14 ____ 1939 Apr 25-26 _______ 86 __ 51 ____ -35 _t14 ____ 1959 Mar 21-22 _______ 69 __ 34 ____ -35 ____________________________________________ The largest differential in the opposite direction was 34 F deg, set on these four occasions: * Dec 22-23 1871 rose from max 21 to 55 * Feb 5-6 1918 rose from max 4 to 38 * Mar 15-16 1935 rose from max 43 to 77 * Apr 11-12 1977 rose from max 56 to 90 Since the last of those, 33 deg is the highest day to day rise, achieved Apr 8-9 2001 (45 to 78). The only previous 33 deg rise was Apr 6-7 1929 (56 to 89). So these all told are the top six in the upward direction.

I won't calculate any preliminary scores, will leave the outcome hanging in suspense until we get to the actual end of the month numbers, partly because I think the outcome lies perhaps within the margin of error. RodneyS had a bit of a lead on DonS and wxdude64 going in, but their forecasts are different enough that either Don or wxdude64 could in theory edge past RodneyS at the final showdown. Then I looked further down the annual scoring table, Tom has an outside chance of catching some of the three leaders but would need to max out on all differentials he's holding (a colder ATL, IAH and a milder SEA for example). My plan is to go ahead with a contest for 2023 and see how it goes. Any ideas about expanding our field welcome up to and including a change in management. It might just be that more Am Wx forum members would participate even if nothing else changes but the brand name, but if anyone thinks they would like to give that a go, I would be quite glad to co-operate in that venture. And certainly any new contest manager should feel free to change anything about the format. It is what it is, and I am also happy enough to continue on, it's a small but enthusiastic and contest-loyal group we have so it's also fine to keep going as is. Whatever, have a great holiday and check in around January 1-2 to see what happened. There will be the usual January relaxed late penalty call for forecasts around 27th of December.

Let's go for 50 ... sets up a chance of breaking the record day to day change in maximum which I believe was 41 in the Feb 1918 event shown in the list. Will edit my table for that list which is somewhere back in this thread, when tomorrow is in the books.

I ran a program on the data base and here is the full list of 38+ daily ranges (1869-2022); as Don mentioned, 48 is the maximum but in terms of winter synoptics 43 (58/15) on Jan 9, 1978 seems to be the largest range from this type of deep freeze plunge (the record was a cold front too but in late March 1921). The occasions with ** marking are also in the list of largest day to day changes in maximum temperature that I posted earlier in the thread and will update from 23rd and 24th max data. The largest change there was 41 deg in Feb 1918. I have identified the cause of the large range which can be warming especially earlier in the records when there was a smaller urban heat island, at the onset of very warm spells. So the list of largest ranges caused by a daily cooling trend is smaller than this list, as about one third that I have identified are large (mostly spring month) warmings rather than created by a cold front. This is a long list but it may help anyone interested in finding similar synoptic situations. l can now edit in Dec 23, 2022 apparently the new champion of the big range at 50 F deg difference (58,8). Rank ___ Date ______ Range from Max, Min ___range due wx colder or warmer? _ 01 ____ Dec 23, 2022 _50 __ 58 __ 8 ____ cold front _ 02 ____ Mar 28, 1921 _ 48 __ 82 _ 34 ____ cold front (prev day 60/47, next day 42/26) _ 03 ____ Apr 25, 1915 _ 44 __ 91 _ 47 ____ could have been either or both (67,91,72,92,54) _t04 ____ Apr 7, 1929 __ 43 __ 89 _ 46 ____ warming from prev day max 56, next day 88 _t04 ____ Jan 9, 1978 __ 43 __ 58 _ 15 ____ cold front (next day 21/12) ^ _ 06 ____ Mar 13, 1990 _ 42 __ 85 _ 43 ___ warm spell with large diurnal ranges (also 35 range 15th) _t07 ____ Feb 20, 1918 _ 41 __ 59 _ 18 ____ cold front, next day max 18 (this is largest day to day change) ** _t07 ____ Mar 18, 1934 _41 __ 71 _ 30 ____ cold front, next day max 36 min 22 ** _t07 ____ May 19, 1962 _41 __ 99 _ 58 ____ warming, prev day 89/56, next 90/64. (May's highest max) _t07 ____ Mar 20, 1986 _41 __ 62 _ 21 ____ cold front, next day 36/18 _t07 ____ Dec 22, 1998 _41 __ 63 _ 22 ____ cold front, next day 29/18 _t12 ____ Dec 2, 1942 __ 40 __ 58 _ 18 ____ cold front, next day max 30 min 18 _t12 ____ Jan 23, 1957 _ 40 __ 60 _ 20 ____ cold front, next day max 27 min 16 _t12 ____ Apr 27, 1962 _ 40 __ 91 _ 51 _____ warming, prev day 71/45, next 89/62 _t12 ____ Apr 3, 1967 __ 40 __ 76 _ 36 ____ cold front (prev day 81/61, next day 50/32) _t12 ____ Apr 12, 1977 _ 40 __ 90 _ 50 ____ warming (prev day 56/42, next day 88/60) _t12 ____ Mar 18, 1989 _40 __ 77 _ 37 ____ cold front (prev day 70/42, (77/37), next day 46/31) _t12 ____ Apr 27, 1990 _ 40 __ 91 _ 51 ____ warming, next day 90/69 _t12 ____ Apr 4, 1995 __ 40 __ 68 _ 28 ___ cold front, next day 39/23 _t20 ____ Apr 8 1871 ___ 39 __ 85 _ 46 ____ next two days very warm (83, 80) _t20 ____ Jan 10, 1876 _ 39 __ 60 _ 21 ____ cold front (max 9th 56, max 11th 24) ** _t20 ____ Apr 19, 1897 _ 39 __ 68 _ 29 ____ cold front (max 20th 43 min 24) _t20 ____ Apr 1, 1917 ___ 39 __ 83 _ 44 ____could have been either or both (62, 83, 54) _t20 ____ Mar 26, 1922_ 39 __ 76 _ 37 ____ warming, prev day 55/40, next day 62/53 _t20 ____ Dec 8, 1927 __ 39 __ 65 _ 26 ____ cold front (next day max 26) ** _t20 ____ Feb 8, 1933 __ 39 __ 60 _ 21 ____ cold front (next day max 24) ** _t20 ____ Mar 9, 1987 __ 39 __ 62 _ 23 ____ cold front (prev day 76F, next day 28/15) record hi to low max in 2d _t20 ____ Mar 8, 2005 __ 39 __57 _ 18 ____ cold front (prev day 63/43, next day 31/16) _t20 ____ Jan 13, 2018 __ 39 __58 _ 19 ____ cold front (prev day 61/44, next day 25/15) _t30 ____ May 10 1874 _ 38 __ 90 _ 52 ____ cold front, morning low prob'ly 65-70 _t30 ____ Feb 27, 1880 _ 38 __ 68 _ 30 ___ warming, next two days 56, 69 (LYD) _t30 ____ Feb 16, 1896 _ 38 __ 44 __ 6 ___ cold front, max 15th 54, max 17th 7 F ** _t30 ____ Dec 15, 1901 _ 38 __ 60 _ 22 ___ cold front, max 14th 58, max 16th 26 _t30 ____ Apr 27, 1915 _ 38 __ 92 _ 54 ___ probably cold front (see above Apr 25) ** 2nd entry in 3d _t30 ____ Mar 19, 1918 _ 38 __ 76 _ 38 ____ cold front more likely (next day 52/36) _t30 ____ Dec 14, 1919 _ 38 __ 60 _ 22 ___ cold front (61, 60, 27 max 13-15) _t30 ____ Jan 27, 1925 _ 38 __ 42 __ 4 ___ cold front (next day min -2, max 14) _t30 ____ Mar 16, 1935 _ 38 __ 77 _ 39 ___ warming as prev day max 43, next day max 67 (range 34 cf) _t30 ____ Apr 21, 1936 _ 38 __ 81 _ 43 ___ cold front (next day 54/35) _t30 ____ Mar 3, 1938 __38 __ 49 _ 11 ___ cold front (next day 29/9) _t30 ____ Apr 25, 1960 _38 __ 87 _ 49 ___ warming more likely (70/45 prev, 70/52 next) or t'stm? _t30 ____ Feb 25, 1970 _38 __ 54 _ 16 ___ cold front (next day 26/9) ________________________ ^ Jan 26, 1978 perhaps comes to mind, had a 36F range 58 down to 22

^^ Gotta get those last minute stocking stuffers ^^ (CLE guess 18" storm total)

The idea of "too cold for lake effect" is a bit of an urban legend, the lakes warm the frigid air to the extent that it can hold enough moisture to remain very capable of maxing out. Without Lake Erie there BUF would probably drop to 12F but the lake will release enough heat into the squall band to maintain a reading of 18-22F (at a guess).

Some estimates of timing for the front ... in EST NYC _ 1130 central LI w CT 1200 central CT and Springfield MA 1300 ORH-PVD 1340 BOS 1420 Cape Cod 1530 Expect about a one-hour lag for sharp temp drops after the fropa I would expect it to be a discontinuous squall line with isolated gusts to 70 mph possible but 50-55 more general, lasting about a half hour, then 35-45 during the CAA.

Arctic front is about one hour behind that sleety line, temp drops of 20-30 deg in 2 hrs have been reported all through the OV and w PA. It is near -10 F with 35 mph wind gusts in most of western OH, IN and IL. 2-4" snow quite widespread in Ohio and parts of wPA so you may get a coating in some parts of nMD despite the downslope dry out. My guess is the temp at DCA at noon will be 24F, IAD 20F and parts of nMD 15 F. Wind chills below zero.

Looking at radar in WV, front seems to be fairly active, would expect some hail and thunder followed by a few minutes of snow in some parts of the lowlands, a coating of snow across nMD before the strong winds set in, blowing that around. Bright sunshine to follow will not help make driving any easier, and icy patches on some roads quite likely as there could be .10" rain or sleet falls ahead of the fast temp drop. Temps down to 5-10 F by Saturday morning.

Maybe it was 998.2 mb, weather maps include the decimal so a weather station reading 982 is at 998.2 mb.

Give it three hours and it will be almost something instead of basically nothing.

No earthquake warning? With all this air and water moving around, the crust will be under stress, would expect a minor earthquake in NY or PA tomorrow or Saturday. Also new moon on 23rd, so a bit of additional tidal force.

Blending all models with a nowcast on that Alpena forecast, right now it appears to me that some of the guidance is too progressive. The surface low is holding back a bit further west than the hour to hour positions on 18z models and so their 0600z positions appear too far east by at least 50 miles. I think the low will track very close to APN although it will elongate to form a double center with the eastern circulation. So my forecast was based on more of a nowcast approach than any direct model to forecast approach. Lake Huron as you know is quite warm compared to the air mass temperature coming in but so is Lake Michigan and I wonder if the models entirely processed those signatures into the first part of the evolution. All of the upper level circulations are well back to the west of Lake Michigan so a deepening low should in theory try to move towards the upper lows which may pull it back a bit further west at least through 06z. The explosive deepening phase is just starting now. It should continue for the next 12 hours or so.

During the explosive deepening phase I would expect rain to change to ice pellets and then heavy wet snow with thunder quite possible. From my reading of current map and guidance, the rapidly deepening low will head up through central s MI towards your location by 0600z and then may hover in place for a while as it connects through to the eastern center moving north across L Ontario. Eventually it drifts far enough north that you get into much colder air from the west, snow will remain heavy for a while then come and go in bursts as it becomes more lake effect and less synoptic. I think the deepening phase will drive out the 32-35F dew point air over Lake Huron and allow the rain to change phase, but it could go through a couple of oscillations along the way with heavy ice pellets quite possible around 02-04z. Let us know as you're sort of at ground zero for this.

00z NAM looks to be an upgrade especially for s MI. The low stays on the Michigan side of L Huron through the deepening process. I don't know if it does any good for Chicago, but it may mean that some forecast amounts for MI are low. I think this evolution is going to create sustained S+ bands across much of lower MI and amounts of 20-25 inches could occur in a few places. Will go for 22.5" at GRR, 15.0" LAN, 6.0" DTW, 12.5" MBS and 17.5" APN, possibly 18-25" TVC and MKG over the full duration of the storm.

Posted back on Monday, adding the ranks 13-18 (all the 35 deg drops) ... For potential comparison to 23rd-24th change in NYC max temp, these are the top twelve downward differentials from day to day, 1869 to 2022: _ Rank ___ Dates _______________ From _ To ___ diff _ 01 _____1918 Feb 20-21 ________59 __ 18 ____-41 _ 02 ____ 1921 Mar 28-29 _______82 __ 42 ___ -40 _ 03 ____ 1927 Dec 8 - 9 ________65 __ 26 ___ -39 _ 04 ____ 1915 Apr 26-27 _______ 92 __ 54 ___ -38 _t05 ____ 1896 Feb 16-17 _______ 44 ___ 7 ___ -37 _t05 ____ 1978 Jan 9-10 ________ 58 __ 21 ___ -37 _t05 ____ 2003 Apr 16-17 _______ 88 __ 51 ___ -37 _t08 ____ 1876 Jan 10-11 ________60 __ 24 ___ -36 _t08 ____ 1911 Nov 12-13 ________69 __ 33 ___ -36 _t08 ____ 1933 Feb 8 - 9 ________ 60 __ 24 ___ -36 _t08 ____ 1970 Feb 3 - 4 _________56 __ 20 ___ -36 _t08 ____ 2014 Jan 6 - 7 ________ 55 __ 19 ____ -36 _t13 ____ 1890 Feb 5 - 6 ________ 68 __ 33 ____ -35 _t13 ___1898 Dec 31-1899 Jan 1_ 53 __ 18 ____ -35 _t13 ____ 1918 Jan 12-13 _________53 __ 18 ____ -35 _t13 ____ 1934 Mar 18-19 ________71 __ 36 ____ -35 _t13 ____ 1939 Apr 25-26 _______ 86 __ 51 ____ -35 _t13 ____ 1959 Mar 21-22 _______ 69 __ 34 ____ -35 _t19 ____ _t19 ____

I saw that attempt at a loop GFS, just like the Euro once had. I think what that loop means is the model recognized the main shot of energy and allowed it to take over from junior out ahead. Maybe it will happen that way or maybe there will be more of an organized low coming out of Texas. Might be almost nowcasting the details. Models are still losing the western center after it drops into TX. Isn't there a general tendency for models to underestimate snow potential in the Mississippi valley region? Seems that way over the past few seasons. There was that recent winter with the record snowfalls in Moline, La Crosse and MSP and it seemed like half that snow was not in the forecasts. Was that winter 20-21? (no it was 2018-19 time flies)

00z RGEM to 48h looks like a storm recovery trend may be slowly underway? An interesting night of model watching lies ahead.

Apologies if my comment seemed related to that, I was just commenting on a graphic in somebody's post showing the low tracking further east in Ontario than what I recall. That was possibly the track of the triple point though. In Toronto we went from 40F and rain at 0700h to 18F and snow two hours later. The fropa had wind gusts over 70 mph locally whether that was picked up at airport or not, in fact where I normally parked there was a big a/c unit that had blown off the roof five minutes before I arrived for work. So that plus the fact it was still mild at 0700h tipped me off that the prog position had busted.

That's all quite interesting about 1-26-78 but the actual storm track was closer to Sarnia-Port Huron and up Lake Huron, I was actually in a weather office drawing up a map at 0800h and still have the map. There was a pressure of 955 mb at Sarnia and at one point maybe around 09-10h London ON had hurricane force southerly winds that were wrap-around arctic air. This won't quite get that wrapped up anywhere. I realize the technology has improved but the 24h prog position of that storm was over western Lake Ontario (it came up from around central AL). We were expecting a snowstorm in Toronto and got one from the wrap-around instead of northeast winds, so the public were not that aware of a forecast bust. I think it probably came as more of a shock further west, the intensity was quite unforeseen in southwestern ON. Those winds knocked down several large hydro-electric towers in that region. You don't often see arctic air blowing from the south in that part of the world.

This thing is over me here and we are seeing three times the model predicted snowfall (easily a foot and maybe more, we had a forecast of 3-6 inches). Some model runs have had a sub-960 mb low over central ON and the trajectory looks perfect for another mega-squall event around BUF and wNY. On current guidance I would think 60-90 inches quite possible 24th-26th with extreme winds (although squall bands tend to do odd things with winds inside the heavy snow zones). Similar to mid-November, your seasonals are going to go through the roof. Is Buffalo scheduled to be playing at home during any of this? There were events something similar to this in Nov 1970 and Jan 1971, that was quite a snow belt winter.

Just hope Belicheck doesn't send in the play. Mind you, you want this thing to run back towards its own end zone.

Both NAM and GFS look a bit off in their handling of the short wave rounding the base of the trof, they seem to be trying to develop the eventual low out of the leading wave and trof in place ahead of the energy and they suppress the short wave as a sort of last piece of energy for the southeast U.S. cold front. I think earlier model runs may have had a better depiction with the energy rounding the base of the trof deepening over MO and IL rather than this concept of the low forming in IN and moving to MI. Either way all of the expectations for MI, sw ON, wNY snow belts would verify but there may be a better (worse for public) outcome for WI and IL, maybe even IA and MO. Later model runs (perhaps starting with 12z Euro) may start to drift back to the earlier more intense solutions. I can't see how the overperforming start here would translate into a weaker short wave rounding the base after DEN gets a brief blizzard tonight and Wed a.m., would expect a snowstorm to develop in OK and s KS as the low drops into Texas. I think it will stay more of a dominant feature rather than getting absorbed into some developing low way out ahead of the main energy.

FWIW the low moving on shore now has overperformed in terms of snowfall across southern BC, Vancouver region has 8-12 inches after a forecast of 3-6, and here inland (north of Spokane at the border) we also have 6-8 with same forecast. The low is just south of Bellingham WA with a leading wave near Spokane.