Roger Smith

While some models have changed a bit, the weighted six-model consensus seems similar, perhaps a touch less dual-centered. More and more this looks like a two-jack storm, one near an axis NE-SW through ORH and the other from PSF to BGM. I think a few locations (maybe not airports) will break 20" with this one, big station or airport max 15-18. The less dual centered this turns out, the stronger wind potential -- a dual centered low is always a bit bland with wind speeds, I feel. Still peak gusts over 60 mph in a dual, but potential for 80-90 with a lone center. Most likely location for these maximum wind gusts would appear to be around Plymouth MA. Will give the 00z suite a six-model analysis and see what the consensus looks like then. My subjective forecast aside from doing it this objective way is a 976 mb low moving past Cape into western GOM, tiny loop and back to the southeast. I think that might increase snowfalls to 20-25 inches in places but still the max axis is near ORH. It would reduce the PSF-ALB-BGM totals to 12-15 as a secondary max.

JMA also has double centered low but components closer, western over RI at 54h. Calculated the weighted six-model consensus and came up with this scenario: to simplify, take GGEM but instead of its unified low, at all time frames 42h to 54h allow for a two-centered system 2 deg long apart, in other words, one would be 1W and the other 1E. Consolidate them in eastern center by 60h. Based on that, first call forecasts: se MA all rain until tail end of storm, 1-3" BOS mixed periods giving 3-6" followed by 4-7" all snow, pack at end 8" PWM 5-8" snow CON 8-12" snow (Ray some taint followed by mostly snow, 7-10" ORH 15-18" PVD rain followed by snow, 3-6" (Kev) 10-14" BDL 5-8" s CT mostly rain ends as 2-5" snow PSF 18" ALB 16" NYC 2-4" ISP sleet, rain, melting snow to coating at end ________________ If solution is more unified one-center low and GGEM proves best guidance, then double most of those other than NYC.

ICON and RGEM don't look much different (have only seen RGEM to 48h but looks to be in early explosive deepening south of RI heading for ACK, ICON was a bit deeper than 00z on almost the same track). Feel like NAM just didn't have the southern stream available for phase because of the odd shape of the 500 mb flow southeast of the upper low, so the northern stream has to do it all alone. If intense solutions continue today, I think it's time to hoist the B flags and get the public ready for a disruptive snowstorm, and in some places windstorm. Not that it's going to impact my life, but I too have been waiting for an intense storm to hit the charts on your side of the continent. We've had enough here. My snow pack is a measured 22" and my estimated season total is 90". Probably 3-4 feet in some higher alpine areas around here.

06z NAM has a weird looking evolution where the southern stream wanders off towards Bermuda then shows up south of Nova Scotia while the nothern stream deepens very gradually and they hold hands but don't phase. Would be much less windy but snowfall implications are not that different, puts NYC in the game. Probably not how this beast actually works, might be a failed attempt to deepen the system from earlier NAM track. Think the other 06z guidance will hold serve. (06z ICON looks similar to 00z except slightly more intense, no visits to Long Island there)

Update, heard from Tom and so_whats_happening, both were having problems with either connection to site or health and hope to be back with us soon. Meanwhile, here is the first report on anomalies and projections: __________________________ DCA _ NYC _ BOS __ ORD _ ATL _ IAH ____ DEN _ PHX _ SEA (11th) ___ (10d anom) ___ +4.3 __+2.3 __+2.9 __+4.6 _+10.0 _+8.8* __ -4.0 _ -5.0 _ -5.4 (21st) ___ (20d anom) ___+0.4 __ +0.9 __+2.4 __-0.5 _ +1.0 _ +2.4 ___ -3.7 _ -3.0 _ -2.5* _ * est, one day msg data (11th) ___ (p20d anom) _ +2.0 __ +1.0 __ +1.5 __+2.0 _ +6.5 _ +6.0 ___ -3.0 _ -3.5 _ -3.5 (11th) ___ (p27d anom) _ +1.5 __ +0.5 __ +1.0 __ +1.5 _ +5.0 _ +5.0 ___ -2.0 _ -2.0 _ -3.0 (21st) ___ (p31d anom) _ +1.0 __ +1.5 __ +2.0 __ -1.5 _ +2.0 _ +3.5 ___ -2.0 _ -2.0 _ -1.5 (25th) ___ (p31d anom) _ +1.5 __ +2.0 __ +2.5 __ -1.5 _ +2.0 _ +3.5 ___ -2.0 _ -2.0 _ -2.0 (31st) ___ (final anoms) __+1.5 __ +1.8 __ +2.5 ___-0.2 _ +2.4 _ +3.4 ___-5.7 _ -4.5 _ -2.6* * SEA continues to be missing one max and one min, but a nearby location had values very similar to the monthly averages generating the -2.6 anomaly, so will not adjust that. Will however check for later adjustments (this also happened back around July 2022 and the missing data never appeared). ======= (11th) _ Rather cold for the next few days in most eastern and central locations, more variable later. West has started quite cold but looks to be closer to normal rest of the way, so the large anomalies are gradually reduced. Never looks quite cold enough to flip the positive anomalies in the east, and the southeast will only cool to near average at times. Best forecast looks to be a battle between wxdude64 and DonSutherland1. SL also good but needs west to warm more. (21st) _ Anomalies are converging on zero to +1.5 and a good stretch of mild weather looms, but very cold guidance for 29th-31st in east, more like 27th-31st central. Going with a balance of just above normal values for this blend. SEA missed one max and one min in their CF6 to date, looked like the missing values were well above normal so I adjusted the reported -3.1 to -2.5. Snowfall contest report also updated to the latest reports. (25th) _ New set of provisionals for end of month as models have downgraded the intensity of cold outbreak near end of month. Will adjust scoring as a result. Only the three eastern locations and SEA have been adjusted. (31st) _ Posting final anomalies overnight, now all confirmed. Scoring will be adjusted by morning of April 1st.

The North Atlantic SST map seems to show that the Gulf stream has moved a bit south of where it was during most of the winter, to around 38N, and that may be another small factor in favor of a snowier outcome, I would not want to see 55-60F water just a few miles away from ACK, instead it seems to be low 40s and even at the benchmark it's just 49-50F. This would also argue for rapid intensification as the low moves from 37N to 39N across the core of the Gulf stream and the last opportunity to interact with warm ocean.

A lot of us seem to have outside the BOX thinking.

18z JMA has more distant stall like 18z NAM. I weight them 2% each so that moves the consensus 10 miles east. And where is the consensus (based on 30% Euro, 30% GFS, 20% GGEM, 10% UK, 6% RGEM, 2% JMA, NAM) you may ask? Works out to being a loop or stall 30 miles e.s.e. BOS at 978 mb. From that, I have to say that 2" for ORH is a heck of a gamble, must be based more on thermals than track and dynamics. I would go with 10" for ORH expecting 15-20 quite possible. I also wonder if the damaging wind and storm surge potentials are being underestimated. Lucky this falls halfway from full to new moon (at the moon's approach to its southern declination max which nowadays is a hefty 27 deg as we approach the peak of an 18.6 year cycle). I think that tidal forces on this developing low will add that useful 20-30 mile southeast pull at around 12-18z Tuesday.

Two questions about RGEM, I only see it going out to 48h on EC website, does it really go to 84 or does some vendor just find the corresponding GGEM maps and tack them on? And if it really does go 60, 72, 84 where do you find those? TIA.

That GFS depiction looks extreme for wind gust potential across southeast MA, 90 mph, and thermals look good for all snow anywhere north and west of a BOS to s/c RI line. If that verified would expect 25-35 inch snowfall potential ORH to ne CT, frequent thundersnow. Obs around BOS would be the whole catalogue of precip types before it went over to all snow after the loop. 974 mb is fairly low but I was more taken by the rate of deepening as it approaches, if it was steady state then 70 mph, but that deepening is epic. I also noted that the GEM produced a lower 500 mb height at capture. Let's say that was also correct then this GFS depiction could become more extreme. This would only be a rainer if it (a) moved inland over LI and CT and (b) the dynamics stayed modest enough to prevent high precip rates. Some model runs we saw earlier were like that but now it seems to be swinging to an extreme storm scenario.

Thanks on top of thanks Don, from that I surmise that this winter has no way of finishing first, would currently rank second as is, and could fall a few spots but given 10th 1952-53 had a cooler winter and 15" then I'm guessing the winter has a top ten locked up no matter how much snow these two events produce (within reason).

LB, I remember the March (and late April) 1990 heat, I was living near Peterborough, ON back then. Moved west in 1995 just after the 100 degree heat and derecho went through. That March 1990 spell had to melt a foot of snow to become fully effective at my location but even so we made it to about 70 degrees. I used to watch a TV station out of ROC (no cable, pulled in on an antenna) and they hit 80 IIRC. Records were not just falling, they were being crushed into powder.

Don as you approach this five-day interval of snow possibility, could you post the top ten or maybe twenty of the futility index? Also could you show what if anything happens to 1997-98 after that later 5.0" snowfall? Does it drop by one or two ranks then? And if it's not too much trouble could you post the top ten outcome (end of snowfall season since the temp component is already known) list? TIA.

Weighted six-model consensus track would be eastern LI to PVD to 50n BOS to 50e PWM, consensus central pressure 982 mb. I noticed JMA 12z was 10 mb weaker than 00z and close to GEM for track. Seems like present state of play is 70% chance snow line would be along that consensus track. Maybe one in three chance of a track further east across some portion of se MA, improving snow chances and potential totals towards 20-30 inch jackpots ORH to CON. I do foresee a southward shift of 100 miles in the developmental phases, and would not currently make a first call based only on the Euro.

I looked, I ran. They looked, teh ran. But the Iraqi is good, I raq up three feet. Actually, in reality I am under the primary now, out here 150 north of GEG, and it's a nice scene of innumerable tiny flakes that have managed to lay down 2" in three hours. Trying not to waste any of your 30" as we already have that on the ground and I am not greedy.

JMA destroys almost everybody, it's a godzilla storm. I heard they just upgraded that model too. Interesting to see if it performs here (it would be slower, deeper and slightly further southeast than most other guidance) http://www.meteociel.fr/modeles/jma.php?ech=120&mode=1&nh=1

FWIW the JMA has a slower evolution to a deep low near Nantucket (972 mb by 00z Wed). It's a similar evolution to the most recent Euro but slower by at least 6h. Significance may be a tick slower for model consensus, would not buy into the timing but the track and intensity look great for 20-30" snowstorm. Will see if the 06z GFS is moving any closer to the Euro again, the models have more or less flip-flopped in terms of which ones are inland and which ones are coastal. NYC potential at the moment is in a very wide range (3-20), further up the river, more like 6-24. Snow from earlier event will chill the boundary layer which is one reason why an inland runner seems unlikely, at least inland west of Fall River to Chatham MA.

FWIW the JMA has a slower evolution to a deep low near Nantucket (972 mb by 00z Wed). It's a similar evolution to the most recent Euro but slower by at least 6h. Will see if the 06z GFS is moving any closer to the Euro again, the models have more or less flip-flopped in terms of which ones are inland and which ones are coastal. NYC potential at the moment is in a very wide range (3-20), further up the river, more like 6-24. Snow from earlier event will chill the boundary layer which is one reason why an inland runner seems unlikely, at least inland west of Fall River to Chatham MA.

Will likely be a tune up for the Monday event, 1.5 to 3.0 potential at most. Monday-Tuesday could be 5-10 times that in some model scenarios. Seems like 1972-73 is calling, the message says "you need a warm March to beat me."

Anyone able to update us on the Korean model that had the super-bomb yesterday? My approach if I had to make a forecast now would be to take a weighted average of GFS, Euro and GEM, ignore the rest. The weight should be something like 40-30-20 in that order. On that basis you come up with a very nice solution, not quite as tucked or intense as Euro, at times a bit south of GEM, closer to land than GFS and 5 mb deeper too. Let's say a 978 mb low near the benchmark from an origin near ACY. It would perhaps cut back a bit on Euro QPF but would spread 15-25 inch snowfalls over most of the region. I wouldn't call that "my" forecast because it's just a paradigm approach, if the models diverge, then split the difference, they can't all be right but sometimes none of them is exactly right compared to the others. GEM at the moment is intermediate in nature to GFS/Euro so a second approach might be, go with the intermediate of the three but skew that slightly towards the one of the other two you trust more. Frankly I trust the GFS more than the Euro but I hope for the best for your sake. I don't want to be the only poster here to reach 50" on my season (it is child's play here).

3-5 take a break then 30-50. This is becoming like a fat man at an all you can eat buffet.

A good analogue may be March 3-4, 1960. Check out this map and the outcomes were high on the NESIS scale. http://www.wetterzentrale.de/reanalysis.php?map=2&model=noaa&var=1&jaar=1960&maand=03&dag=04&uur=1200&h=0&tr=360&nmaps=24#mapref

The forecast was toast.

Once again, GFS-GEM-Euro equally weighted blend looks better than any of them individually. An intense version of that would be quite productive. Think the blended track would be ideal for most. I suppose it's usually the case that one model wins out over the others, but maybe in this case they would all move to a compromise solution with track across the benchmark and into western Gulf of Maine. Let it loop or stall there.

1717 ... 1888 ... 2059 ... you'll just be 78 which will be like 55 today.