Roger Smith

I invented a new term as a result of this event: BUSTARD Obviously, an actual blizzard did happen n.w. of a given line, and storm performed reasonably well in many areas except greater Chicago, model guidance was relatively poor given actual outcome, primary or n.w. center never decayed or gave way to southern center even as they blended over michigan, and it went over south end of Lake instead of south of lake; all contributing to a bustard for Chicago where a blizzard was expected. It was a bigger bust than just lake-induced higher boundary level temps, that was part of problem, but if Euro pressure predictions had verified, I feel certain that ORD would have reached 12" and rain would have tainted only briefly and near lakeshore. The nam did better than most, in retrospect, perhaps keep it and toss Euro (now a supposed wonder of a.i.)? I realize there are different sources of funding, but if this is any indication, we have little to fear from a.i. domination except endless irritating references to it. I'll consult Alex rather than Euro from now on. ... my idea of going with 80% Euro snows would be better set at 30-40% at least in some areas. Even GFS snows were a bit inflated although better. It is what it is, but an enjoyable event to watch and try to decode, however unsuccessfully.

Keep in mind, a map or any representation of differences in normals (1981-2010) to (1991-2020) is actually a measure of one-third of the difference between (1981-1990) and (2011-2020) because 1991-2010 are two thirds of both data sets. So if a map shows some location warmed by +1.0, it means 2011-2020 was 3.0 warmer than 1981-1990. Under the cold dome here, about -10 F which is probably within a few deg of record low max, about -20 F for overnight lows here. Sky is the same intense blue color that we had during the heat dome in June 2021. Trees are plastered with snow from days ago, and s.o.g. is about 20" in town, 30-40 inches in the nearby ski areas, and 15" down in the Columbia valley. These are near to slighty below average snow depths for our region. Only in January 1950 was there anything colder than what we're seeing across BC now, since 1950, a few other occasions were near equal to today. As I posted yesterday, Watson Lake Yukon had -74F on Jan 31, 1947 so their lowest value so far (-57F measured as -49.4 C) is not record-setting but there are only a few other cases of even -60 F, the 1947 spell was an outlier. Alberta and montana are probably closer to their all-time record lows, quite a heat island showing up for Edmonton, the station you're seeing (YEG) is 15-20 miles out of town, in the city it is running about 10F warmer. The Calgary airport readings are somewhat within suburban portions of their eat island, their airport (YYC) is a lot closer to downtown than YEG. Almost any other weather station in Alberta will have no urban effects, but you do get topographical variations in these calm cold spells, as solar radiation in January is negligible, so the overnight cold stays noticeable in valley bottoms all day.

Would expect two rounds of convection with (a) occluded P front and (b) arctic front about 6 hrs afterwards, so around 0400-0600h and 1000-1200h EST. Will say widespread gusts into 40s but isolated 50s, it's active but not loaded with energy. Temp peak around 10:00h 51-54F. Falling into low 40s after arctic front passes, scattered flurries likely by evening in 32-34F range.

Not quite in the core of the cold but it's -22 C (-8F) and clear here at 10:45 PST. Bit of a north wind giving a -35 C wind chill. Currently -35 to -40 C all over Alberta, even colder in far north, and Watson Lake (s.e. Yukon) is -48 C. We also had record cold last winter but it came earlier in mid-Dec, and did a lot of damage to vineyards in Okanagan valley region (-30 C). Canada's lowest reading ever was -63 C (-81 F) in early Feb 1947 at a location near Alaskan border, Snag, no longer an active weather station, I believe it was about same on Alaska side of border at Fort Yukon. We were reading in F deg back in 1947. I just looked up data, on Feb 3rd 1947 max temp was -57F and low -81F. Every day from Jan 27 to Feb 4 was below -40 but it warmed up to 5F on Feb 9. In same cold spell, Watson Lake's coldest reading was -74F on Jan 31, 1947 (it converts to -58.9 C).

Latest thoughts ... Rather slow improvements will return to n IL as n.w. lobe of dual low is slowly robbed of warmth, better snow rates will return to Chicago after 6 pm and peak around midnight as wind backs to NE then NNE. Further south in IL, done for a while then picks up to moderate snow and blowing snow around 7-9 pm. ... Northern IN holds on to heavy wet snow for a while, dry slots, brief rain/snow mix, eventually N to NW winds bring in lake effect after midnight, blizzard conditions for a while SBN to La Porte. Into w Michigan, slow saturation of surface layers will result in gradual irregular increase in rates until S+ by the time primary low is near FWA and secondary is near s end of Lake Michigan late afternoon-evening, then periods of S+ merging eventually with SW+ from lake effect by morning. That will be the general scenario east to Jackson-Ann Arbor, interval of heavy wet snow likely in Detroit around 5-7 pm and after that intermittent light snow with brief moderate snowfall in decaying lake effect. Wisconsin, apart from some mixing issues at lakefront south of Racine-Kenosha, will get into bands of heavy snow separated by light to moderate, slowly accumulating to reach 12-15 in totals. Winds will increase from northeast and at least blizzard conditions in open rural areas if not all areas. N lower Michigan will rock as discussed in thread. Don't see total bust for MSP but 1-2" blowing around in very cold wind, instead of 4-6" not all that different, would not want to be out in it by tonight (at my location, crystal clear and -8 F at 9:30 PST). Toronto area I would agree with what I read earlier, 5-10 cm this evening, snow, sleet and/or ice pellet showers could include thunder. For many in IL it will be a case of two storm periods and a long pause lasting rest of daylight hours but part two could be quite intense as well. Gradient around secondary low tightens rapidly after about 21z.

Euro also on its own in Europe at similar time scale, brings a fairly big chunk of subtropical low near Azores in towards France at a higher latitude (49-50 vs 45) than other models, difference is about the same (200-300 miles). So in general Euro is currently analyzing all of Atlantic basin differently from rest of big four. I don't like to ride any of the when they are solo against the field. So I would pick GFS and ignore possibly too warm Gem solution. Euro found progression bias, Gem found retrograde bias. Again, GFS is middle solution. GFS cannot bust as bad as Euro or Gem.

Rain, snow or dry cold ... model consensus? Perhaps by Sunday. GFS looks most credible at present range of 120-132h. 6-10" snow potential.

Link to map for Feb 15, 1943. Toronto (downtown) -21F equalled lowest in Feb 1934 (these were lowest values after end of 19th century when in a rural setting weather station reached -25 to -27 several times. http://wetterzentrale.de/reanalysis.php?map=2&model=noaa&var=1&jaar=1943&maand=02&dag=15&uur=1200&h=0&tr=360&nmaps=24#mapref

DTX-YXU-YYZ all same forecast problem, in warm advection period Friday to late o/n, is it sleet, wet snow or rain and snow mixed?? .. urban heat islands will tend to reduce lying snow in metros, would look for 2-4" totals in cities, 4-6" in rural areas, leftover lake effect top ups but snow belt areas will see 6-12" top ups of 8-12 in storm snowfalls for 14-24" totals. For DTX-YXU-YYZ best idea is to warn of moderate snowfall potentials in cities and bad to impossible driving conditions by tail end of storm in snow belt areas to n and w. Snow 10-15 cm potential north of about hwy 7 in s ON, only 2-5 Niagara, 5-10 GTA, but this could bust on high side if warm advection is weak (never seems to happen in current climate). Deep winter is coming, GFS gradually edging towards Euro solution, but in Euro solution you get trade-off of sure blizzard west, sure warm advection mostly rainfall east, so it's a tossup in DTX-YXU-YYZ zone, I would predict along lines of "intervals of rain, sleet and snow, accumulations 5-10 cm" (2-4 in) and stress the travel problems to n and w of zone since it's a weekend and people will be inclined to plan travel in that direction (I would not want to be planning it, roads are going to be closed in snow belt areas by Sat afternoon-evening and returning south later on Sunday will be problematic even if one does get up to ski or cottage areas). I recall bad accident on 400 north of TO in somewhat similar storm march 18 1973, zero vis lake effect on icy snow-covered roadway, trucks piling into stalled cars, on a Sunday afternoon in southbound lanes. On said occasion, Toronto city mostly (1.0") rain, 1-2" snow, suburban areas 0.50" rain, 5" snow, snow belt 8-12" snow.

King euro gives better outcome because it concentrates energy in eastern center now developing over AR while some regional model guidance opts to keep energy balanced with western center now forming over w KS. GFS and Canadian appear to take a compromise position on balance of development, slowly increasing energy balance into eastern center. This can be seen in concentric appearance on Euro and extended double centered appearance on NAM, as well as in differences in central pressure. Solutions with strong primary energy will deepen faster and all-snow regime will consolidate faster also. Euro deepens so rapidly and intensely that it cranks snow out of all available moisture. I would go with something like an 80% Euro outcome as it could be a bit optimistic on balance issue, but the reduction only applies to areas in doubt, 100% Euro would be applicable on colder side of system. For the tricky se Michigan-nw Ohio-ne IN forecast I would go with rain and thunderstorms to about midnight Friday then a rain-snow mix, a windblown 1-3" ground cover by Sat 15z followed by intervals of blowing snow, final stages of powerful squalls dropping 6-12" further west as low moves away. Storm total forecasts: ORD 12, RFD 14, MCI 12, MKE 15, MDW 7, SBN 7, CMI 4, PIA 5, FWA 3, DTW 2, LAN 10, GRR 18, MSN 14, MSP 4, EAU 10, GRB 12, APN 15

GFS cold and intense, near-blizzard conditions would develop. Not having any of what NAM was selling.

The conversation and model spread (even within ensembles) is similar to what I recall last week before New England's snowstorm on the weekend. The outcome was approximately halfway from worst case scenario rain intrusions to best case all-snow, for eastern MA and coastal CT-RI. BOS ended up 3.8", model (and also forum member) forecasts were between zero and 10", snow gradient west and north of BOS quite dramatic, 15" at Worcester and 20" near MA-Nh border. It's difficult to remember which models were saying warm and which were going cold but NAM was definitely not consistent run to run. RGEM was consistent but turned out a bit warmer than outcome. I suspect 18z NAM is outside actual guardrails for this event. If I had to forecast it now, would say 10 inch line Kenosha s.s.w. to ORD and then w.s.w. towards quad cities, max snow 15-20 around MKE and northern lower MI n.e to APN. Dynamic storm with a wicked lake-effect tail for n IN and sw MI. Temps into 47-53F range into nw Ohio could clip DTW briefly, followed by strong winds in occlusion stage, snow into sw ON will cut off near 401 or as far north as hwy 7, but storm could change phase if it creates a coastal in time. Severe storm potential from s.w Ohio to Gulf coast.

06z GFS looks about like NAM but elongates, intense look. Still 72 to go ...

NAM 06z winds up big time about six hours slower and track closer to SBN, GRR. 970 low near GRR. It does look like rather mild air tries to wrap around the center but with that rate of deepening, bands of S+ would likely form almost to center of low.

Euro staying course, I believe. Can't see problems getting cold enough for snow unless it's right beside Lake.

NAM appeared to be a bit stronger to 48 or even 54 (in early development) and then trended slightly weaker into IL, IN, but track only marginally different, noise rather than real change at this range.

The Jan 1978 storm looked similar 48h before blizzard on Jan 24, with low in TX, trof n.e., but it did not make a turn north until it reached AL on night of 25th -26th, then tracked almost due north deepening at double-bomb cyclone rates for 12h, attained a central pressure of 954 mbs near Sarnia-Port huron and eventually tracked between Sudbury-North Bay ON NNE into western Quebec. I looked at maps for all top ORD snowfalls and without other exceptions low pressure tracked NE through IN into central mi or e.n.e. into Ohio, except for Jan 26-78. The Nov 8-9 1913 storm ("white hurricane") followed a similar evolution (GA to sw ON). I don't see potential for a triple phaser as trough development is more moderate but air mass contrast is going to be real and spectacular.

I live at ground zero of that creature (5 mi n of border about 50 west of Idaho panhandle), and we may be close to -20 F by then with 3' of snow on ground (already 18" and not done snowing). Being in mountains we rarely go below -20 F locally, -40 in Calgary AB usually means about -15 F locally. Still believe an extreme outcome is quite plausible for w GL region on 1/12-13, and a large component of ORD snow was always going to be lake effect so track is not as big a factor as gradient and duration. But I do see a range from 6" to 15" in play, and conditions between snowstorm and severe blizzard remain possible. Wave is coming onshore now BC to OR, will be dropping s.e. into Idaho by tonight into early Wed. Better sampling will presumably lead to model consensus and a stronger idea of actual outcome by Wed 18z and Thurs 00z runs. T ursday additional snow potential is a bonus also (now looks 2-5").

LIST of TOP SNOWFALLS (storm totals) first in reverse chronological order: January 31-February 2, 2015 19.3" January 31-February 2, 2011 21.2" January 21-23, 2005 11.2" January 30-31, 2002 12.0" February 18, 2000 11.1" January 1-3, 1999 21.6" February 10-11, 1981 11.2" January 13-14, 1979 18.8" February 6-7, 1978 10.3" January 25-27, 1978 12.4" January 9-10, 1977 10.9" April 1-2, 1970 10.7" March 25-26, 1970 14.3" December 22-23, 1969 11.3" January 26-27, 1967 23.0" February 23-25, 1965 11.5" December 22-23, 1961 11.7" December 19-20, 1960 12.5" March 2-3, 1954 11.8" December 14, 1951 10.0" December 5-8, 1950 13.3" December 10-11, 1944 10.9" January 30, 1939 14.9" December 9-10, 1934 11.3" February 6-7, 1933 12.7" March 7-8, 1931 16.2" March 25-26, 1930 19.2" December 17-20, 1929 15.0" March 30-31, 1926 12.6" January 6-7, 1918 14.9" January 12-14, 1910 10.2" February 18-19, 1908 12.8" December 12-13, 1903 11.6" February 3-5, 1901 12.7" February 28, 1900 11.3" March 23-24, 1897 10.0" February 12-13, 1896 12.0" February 3-4, 1896 12.5" November 25-26, 1895 12.0" February 6-7, 1895 13.4" December 27, 1894 10.1" February 12-14, 1894 11.0" January 18-20, 1886 14.0" ... and then in order of total snowfall ... 1. Jan 26-27 1967 ______ 23.0" 2. Jan 1-3 1999 _________21.6" 3. Jan 31-Feb 2 2011 ___ 21.2" 4. Jan 31-Feb 2 2015 ___ 19.3" 5. March 25-26 1930 ___ 19.2" 6. January 13-14 1979 __ 18.8" 7. March 7-8 1931 _______ 16.2" 8. Dec 17-20 1929 _______15.0" t9. Jan 6-7 1918 ________ 14.9" t9. Jan 30 1939 _________ 14.9"

I would say the Thursday frontal wave could lay down 1-3" snow ahead of the heavier blizzard snowfalls, and when the low starts developing early Friday over OK-AR, the frontal boundary will be about where the low is supposed to track, so cold air will be well entrenched over n IL and all of WI, even parts of w mi west of GRR to APN. Temps during the blizzard would be around 28-31F near ORD due to lake moderation, but would quickly fall off to 15-20 F in w IL and 20-25F in e/c IL. The warm sector would get quickly squeezed out from colder air encircling the low and occluding fronts to force a new center to develop near Lake Ontario on Saturday.

If GFS verified would expect 15-25 in snowfalls (local 25-35) in parts of IL, IN, se WI, w mi, and 6-10 ft drifts in 50-70 mph winds, especially in snow belt additional snowfall zones. Continuous deepening for 24h and L michigan enhancement would combine to produce severe blizzard conditions. Gem is not quite as strong but 10-20 local 20-25 and 4-6 ft drifts, 35-55 mph .

Is there a list of top Chicago snowstorm amounts on 1-d and 2-d basis? I know 1-26/27-1967 is tops but what does the top ten look like?

Scoring is adjusted now that DCA finalized their report at +3.8 (all but one scored four points higher as a result).

Euro on a definite Chicago blizzard track there. It's not a model to over-deepen at 96-120h so would take its 975 mb central pressure, factor in lower GFS and go around 972, all tracks give IN and michigan a snowstorm too. STL may claw back some of that 54" after all (now back into 10-15 range).

The GFS track looks like 30-40 cm potential for Toronto and 40-60 cm western end of L Ontario. STL went from 54" to 2" -- but it's early days yet. I can't see it moving any more to east now, track could edge back west.