Roger Smith

Texas temp range is presently 4F to 87F, near-blizzard in ne OK and e KS. Still needs the uppers to co-operate but the surface components are impressive. If only the upper low was not so flabby -- I need to pump you up.

Looks similar to mar 1-2 1980 incl record cold air mass.

18z nam is a weaker and more OTS evolution than 12z was.

What it looks like now ... raging blizzard across KS, ne OK, weak and undeveloped wave s.e. of DFW, tropical energy on low simmer in western Gulf. 500 mb low (529) developing slowly in larger upper trof n/c mN. It's a waste of a great set up to have such a flabby upper low, but if that starts to develop at any faster rate than the majority of guidance assumes, look out. It is the weak point, all the necessary surface ingredients are in place. I think it's like a 1 in 20 chance for significant development (n of 37N) and a 1 in 10 for last- minute partial development increasing snow potential from 0-2" to 2-5".

Preliminary scoring for Feb 2025 based on projected end of month anomalies posted above ... raw scores only for now, max 60 rule will be applied later if needed. If scores don't improve, max 60 will bring them up considerably. Confidence in projections is a bit less than ideal, scores could change. FORECASTER ____________ DCA_NYC_BOS__ east __ ORD_ATL_IAH __ cent _ c/e _ DEN_PHX_SEA__west __ TOTAL StormchaserChuck _______ 00 _ 00 _ 00 __000 __ 00 _ 64 _ 96 __160 _160 _ 72 _ 60 _ 84 __ 216 ___ 376 DonSutherland1 ___________ 06 _ 00 _ 00 __006 __ 00 _ 76 _ 90 __166 _172 _ 54 _ 50 _ 80 __ 184 ___ 356 BKViking __________________ 08 _ 00 _ 00 __008 __ 58 _ 80 _ 24 __156 _164 _ 90 _ 38 _ 34 __ 162 ___ 326 so_whats_happening ______ 14 _ 00 _ 00 __014 __ 00 _ 96 _ 96 __192 _206 _ 68 _ 74 _ 54 __ 196 ___ 402 hudsonvalley21 ____________ 18 _ 02 _ 00 __020 __ 00 _ 72 _ 40 __112 _ 132 _ 58 _ 44 _ 09 __ 111 ____ 243 wxallannj __________________ 34 _ 12 _ 14 __ 060 __ 48 _ 56 _ 32 __136 _ 196 _ 98 _ 54 _ 26 __ 178 ___ 374 ___ Consensus ____________36 _ 10 _ 06 __052 __ 30 _ 72 _ 40 __ 142 _ 194 _ 74 _ 54 _ 38 __ 166 ___ 360 wxdude64 _________________40 _ 28 _ 26 __094 __ 30 _ 62 _ 22 __ 114 _ 208 _ 76 _ 46 _ 14 __ 136 ___ 344 RodneyS ___________________44 _ 22 _ 14 __ 080 __ 36 _ 70 _ 56 __ 162 _ 242 _ 66 _ 74 _ 80__ 220 ___ 462 Tom ________________________48 _ 10 _ 00 __ 058 __ 06 _ 42 _ 16 __ 064 _ 124 _ 80 _ 54 _ 12 __ 146 ___ 270 Scotty Lightning ___________ 50 _ 20 _ 20 __090 __ 30 _ 30 _ 20 __ 080 _ 170 _ 70 _ 60 _ 00 __ 130 ___ 300 Roger Smith ________________64 _ 46 _ 40 __ 150 __ 74 _ 40 _ 40 __ 150 _ 300 _ 40 _ 54 _ 40 __ 134 ___ 434 RJay _______________________ 70 _ 40 _ 30 __ 140 __ 40 _ 80 _ 70 __ 190 _ 330 _ 66 _ 40 _ 40 __ 146 ___ 476 ___ Normal _________________ 70 _ 40 _ 30 __ 140 __ 40 _ 20 _ 00 __ 060 _ 200 _ 90 _ 40 _ 00 __ 130 ___ 330 Persistence __ (Jan 2025) __64 _ 90 _ 52 __206 __ 92 _ 00 _ 00 __ 092 _ 298 __ 00 _ 16 _ 64 __ 080 ___ 378 EXTREmE FORECAST REPORT DCA, NYC, BOS, ORD, SEA are likely to be wins for coldest forecasts (RJay, RSx3, SC) IAH and PHX will likely be wins for warmest forecasts (SC, swh) ATL and DEN are not presently qualifying. ========================================================= (forecasts) FORECASTER ______________ DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA StormchaserChuck ________+4.0 _ +3.9 _ +3.2 __ +2.8 _ +5.8 _+5.2 __ +0.9 _ +1.0 _ -4.7 DonSutherland1 ___________ +3.2 _ +3.0 _ +2.5 __ +2.5 _ +5.2 _+4.5 __ +1.8 _ +0.5 _ -4.5 BKViking __________________ +3.1 _ +2.3 _ +2.0 ___ -0.9 _ +3.0 _ +1.2 __ -1.0 _ -0.1 __ -2.2 so_whats_happening ______+2.8 _ +2.6 _ +2.4 ___ +2.9 _+4.2 _ +4.8 __ +1.1 _ +1.7 _ -3.2 hudsonvalley21 ____________+2.6 _ +1.9 _ +2.1 ___ +2.2 _ +2.6 _ +2.0 __ +1.6 _ +0.2 _-0.9 wxallannj __________________ +1.8 _ +1.4 _ +0.8 ___ -0.4 _ +1.8 _ +1.6 __ -0.3 _ +0.7 _ -1.8 ___ Consensus ____________ +1.7 _ +1.5 _ +1.2 ___ +0.5 _ +2.6 _+2.0 __+0.8_ +0.7 _ -2.4 wxdude64 _________________ +1.5 _ +0.6 _ +0.2 ___+0.5 _ +2.1 _ +1.1 __ +0.7 _ +0.3 _ -1.2 RodneyS ___________________+1.3 _ +0.9 _ +0.8 __ +0.2 _ +2.5 _ +2.8 __ +1.2 _ +1.7 _ -4.5 Tom _______________________ +1.1 __ +1.5 _ +1.5 ___ +1.7 _ +1.1 __ +0.8 __ +0.5 _ +0.7 _ -1.1 Scotty Lightning ___________ +1.0 _ +1.0 _ +0.5 ___ +0.5 _ +1.0 _ +1.0 __ +1.0 _ +1.0 __ 0.0 Roger Smith _______________ +0.3 _ -0.3 _ -0.5 ___ -1.7 __ +1.0 _ +2.0 __ -3.5 _ +0.7 _ -2.5 RJay ________________________ 0.0 __ 0.0 __ 0.0 ____ 0.0 _ +3.0 _ +3.5 ___ +1.2 __0.0 _ -2.5 ___ Normal __________________ 0.0 __ 0.0 __ 0.0 ____ 0.0 __ 0.0 __ 0.0 ____ 0.0 __ 0.0 __ 0.0 Persistence __ (Jan 2025) __ -3.3 _ -2.5 _ -1.1 _____ -2.6 _ -4.1 _ -4.4 ___ -5.9 _ -1.2 _ -3.7 ============================= [] =============================

Anomalies and projections after 15 days ... ____________________________DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA ___ (anom 1-15) ___________+1.6 _ -1.0 _ -2.1 ___ +0.6 _ +9.6 _ +10.8 __ -0.9 _ +5.9 _ -9.5 __ (p anom 1-28) __________ -1.5 _ -3.0 _ -3.5 ___ -3.0 _ +4.0 _ +5.0 ___ -0.5 _ +3.0 _ -6.0 Very cold for next week in eastern and central regions, more variable later. Staying warm in s.w. and cold in n.w. ... will post preliminary scoring for Feb later. DEN will likely fall to -4 but I expect it will recover most or all by Feb 28.

I posted earlier in thread downtown Toronto's recent snow depth record was 65 cm Jan 15, 1999 after three significant snowfalls in two weeks. That is same as today's value as reported above. I also mentioned Feb 1846 with indications of 30-35 in on ground from approx 40" of snow in eleven days Feb 11-21. There were no snow depth records kept back then.

Surface winds are draining cold air under an inversion at around 3,000' above sea level. Variable winds will likely continue to around noon or early afternoon. NYC is in a sort of dead zone between a leading wave now over NE and the primary low in eastern Ohio. By early afternoon the primary will be near Albany and a coastal low will develop over NYC so I would expect 55-60 F air in warm sector to reach central NJ and fog-laden 47 to 50 F saturated air mass trapped between two fronts over lower hudson valley and LI, NYC, expect a thunderstorm or two in the region followed by partial clearing and strong westerly winds by 3 p.m. -- temps will then fall rapidly.

Looking at all aspects of this developing east coast low, there appears to be wide variability left in play with over 96h to go, therefore I believe a considerable change in final appearance is likely. Whether that works in favor of a larger snowfall event or a totally OTS ending cannot be known yet. One way back to a better event (for DC-BAL) is a deeper 500 low, at present it only drops to 528 which is probably too weak to draw the low into a phase before 70W. If that trends stronger, this can be salvaged.

Room for improvement, but what we see now is only 100-150 miles s.e. of a very big hit with 108 hours to go ... and the upper components probably need less work than surface ... this could still go either way.

First call 1-30 region-wide.

If Jerry Seinfeld was a weatherman he would say, "the average of all guidance is better than any part of the guidance." And Kramer would look startled, then enlightened.

It was probably about what everyone was thinking anyway, from reading the discussion, but I do see a high impact event in parts of MI and ON, if it would intensify faster then IL and IN also. Another analogue might be Apr 2-3, 1975 which was a very high impact snowstorm north of Toronto, due to a 15" storm snowfall being followed by 15" of Georgian Bay lake effect and 50 mph winds. People were stranded for up to a week after that one (despite the late date it was frigid air coming across the Great Lakes and daytime highs below 20 F). I remember that because I was living in the region when it hit, and it was entirely underpredicted at the time.

I suspect this storm will be slow to intensify to full potential but when it does (after 18z) it will begin to create bands of heavy snowfall across most of s ON and se MI, nw OH giving many in those regions 12-15" totals and possibly up to 20" with lake enhancement. There will be some backbuilding as a result of the intensification process and this will help Chicago keep adding with better rates developing, to reach 7 or 8 inches. Given the rush of very cold air around the low as it departs, dangerous lake effect blizzard conditions can be expected in parts of sw Ontario and w NY, and it will also be a significant lake effect snow producer for w MI with more localized blizzard conditions as a result (near GRR in particular). Some parts of the Lake Huron snowbelt could see impassable roads for 2-3 days after this storm winds down. One analogue for the storm (Feb 25, 1965) gave Wiarton ON four feet of snow (generally it was 15-20 inches across s.w. ON). It may seem like it's starting off rather feebly perhaps, but my guess is that it will become a powerful storm around the time it's near FWA to TOL. Will give a specific forecast for DTW, 13.5" and TOL could see 16" due to lake enhancement. CLE is going to get a mixture of snow, sleet and ice pellets with thunder-snow likely to develop over Lake Erie and Lake Ontario regions. Western Lake Ontario could see even more due to lake enhancement but Toronto region in general will see 12 to 16 inches. I don't think it will mix very much as cold air is going to clamp around the low center during the development phase. There won't be much of a coastal transfer until beyond a BTV-BOS axis so only VT, NH and ME are likely to see significant snowfalls apart from a brief interval before the low reaches Ohio, 1-3" will be common inland northeast, but predicting 15-20" in BTV and Montreal.

Toronto (downtown) greatest snow depth in modern times is probably 65 cm on Jan 15, 1999, following 38 cm snow 2nd, 21 cm 12th and 29 cm 14-15th. No snow depth is available in older records but march 1870 and Feb 1846 may have had similar conditions. In Feb 1846 (measured in inches) Feb 11-12 9.0", Feb 15-16 12.0", 17-18 2.5" and 20-21 added 22.0" ... temps were generally below freezing so the total snowfall of 44.5" must have been at least 3/4 on the ground at end of the snowy period. It was followed by record cold Feb 26-28 (lows of -12, -16 and -17 F) and it stayed cold in march although with very little additional snow.