Roger Smith

Western low I was discussing yesterday has become a remnant wave (1014 mbs) located in s/c NE and is still producing a swath of 3-5 in snowfalls in n NE, se SD; these will translate into IA-n mo, then IL-IN-KY quite rapidly, as wave is embedded in 120 kt mid-level jet stream. Feature is in transition to become a slider low that will be merging with weak energy tracking e.n.e. across TN towards sw VA. models have adjusted to reality of best moisture availability as I suspected could be the case given trajectory of western feeder moisture ID into WY last night. Think the 2-4 inch forecasts are solid now, and 4-6 is upper end of what this situation can accomplish, except where orographic uplift yields 6-8. No similarity whatsoever to Feb 1979 storm which exploded off the coast and was interacting with a 1050 mb frigid high near BTV and e ON, sQC. This present situation will create a powerful Atlantic low but that will be racing away Friday night towards central Atlantic Ocean and eventually Ireland by Sunday. The 1979 event on Feb 19 was trapped under the much larger arctic high and deepened rapidly off Long Island. So no real relation at all. Will speculate on totals near 3" for BWI, DCA and IAD trending to near 4.5 to 6.0" on md-pa border. Watch progress of plains states wave into IA-IL to see if it is overperforming; I expect similar totals for a narrow band through those states by 03z. If we happen to see 5-8 in amounts it could be a sign of similar outcome in PA-md-DE-sNJ but I am not expecting to see 5-8 from the level of degradation of wave observed to 18z -- worst case scenario of total disappearance was averted, but system went from an 8 or 8.5 to a 3 on energy level scale. It appears capable of regaining some intensity to around 4/10 by 12z.

When I saw how NAm was handling pressure, popping out a low over VA, I expected snowfall zone to be shifting south further, and it looks odd to have the streak of snow in montana and SD when the storm has shifted towards southeast ID and into WY. It would make more sense to depict snow in NE, s IA, c IL, IN and then KY, WV and VA. Let's see what GFS does in response to what I would expect to be much better sampling of western low's dynamics now that it has been over land for nearly 24h. Skies cleared out here with a measured 17.5" of dry powder, I don't do core samples but it shovels easily so I would guess perhaps 0.60" to 0.80" liquid. No wind so it just settles slowly. Would keep an eye on snow reports later today from places in NE and IA into central IL-IN, if you see 2-4" amounts it may be a sign the fast-paced low is keeping some organization and could redevelop by evening in Ohio, nKY, WV.

First and last call: anyone getting an inch out of this will be super lucky. It's all at my place. I could drop some off just call 1-800-GOT-SNOW. Seriously, I hope it works out better, if only this departing low (now near Yellowstone Park) wasn't being sheared to bits by terrain, and forced to compete for space on Thursday with an arctic high, and it could just glide across the central plains states to VA, then I would say 5-8 inches easy. And it could almost work out that way, a surface circulation may not necessarily always be in evidence, but if the vorticity stayed intact and could trigger a low in KY or WV by late tomorrow, that is a route to getting 3-5 inches at least. But I have a feeling the GFS is correct and it will be a weak norlun feature into Ohio, giving PA-NJ-NYC 1-2" and your region Tr to 1.0" in general (agree on 4-6 west of Blue Ridge). Fingers crossed this plucky little storm can find a way across the hostile arid plains. I did so there's that.

The warmer interval still has some colder days in the mix and very cold air masses tracking southeast into New England and eastern Canada. Any small variations in 7-10 day outcomes from model guidance could bring significant errors in predictions with this tight gradient developing. It looks like several cases of mild air sauntering along oblivious to the presence of predator cold air and I don't totally trust model guidance in such situations, it could bust either way -- the cold could be modelled too aggressively, or the cold could push back harder. Snow has now covered most of the previously bare ground in central regions and more snow is coming there. I suspect there will be two more significant cold and snow intervals, one each in Feb and march.

Slow down, you move too fast. I guess the NAm map could be accurate as a nowcast but bear in mind, where it shows near-zero snow n.w. of Idaho panhandle we have 18" on ground and it's still snowing now. So I wonder about its accuracy downstream into places where snow is just starting. I would expect parts of ID and WY to get almost same as here.

After first half of January (1-16) we have these anomalies and projections ... ______________________ DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA __ (anom 16d) ______ +2.5 _ +4.4 _ +4.8 ___ -1.1 _ -1.0 _ -4.3 __-12.3 _ -5.0 _ -6.0* __ (p anom 31d) ____ +1.0 _ +1.5 _ +1.5 ____ -1.0 _ -1.0 _ -2.5 __ -4.5 _ -1.0 _ -2.5 _end of Jan anoms _+2.3 _ +3.3 _ +3.2 ____ +1.1 _ -0.5 _ -3.0 __ -3.5 _ -0.8 _ -1.0** * SEA missing data 3rd, a mild day nearby locations, assessed as +4 and reported anomaly -6.7 adjusted. ** SEA still missing data 3rd, mild day nearby locations, assessed as +4 and reported anomaly -1.2 adjusted. _17th __ Take about 0.5 to 1.0 off these reported anomalies after today's large negative anomalies (DCA was 17 below normal). DEN on the other hand gained about 1.0 today (+3 anom). Cold to very cold for a few more days in any areas, then generally milder again although a few cold days in the mix. I have basically assumed an average for -1 for rest of January to balance these intervals out. I went with +1 rest of the way for Phoenix and +3 for Denver. We are all going to get smoked by RodneyS for DEN barring a miraculous warming trend, and max 60 may not save us (if RodneyS scores >60). Wxallannj and StormC also are poised to apply misery. _31st ___ Final anomalies are posted, adjusted for SEA because of one day missing data. At DEN, despite last ten days being generally 10-15 above normal, cold was so intense mid-month that anomaly ended up as -3.5. This was also a factor in ORD with three days near -30 anomalies mid-month setting up a recovery from a very low value that ended up a little above average eventually. Snowfall to date (contest post is in Dec and will be merged with this info in the Feb thread. Snowfall to Jan 31, 2024 DCA _ NYC _ BOS __ ORD _ DTW _ BUF __ DEN _ SEA _ BTV _ 7.9 __ 2.3 __ 9.2 ___ 20.0 _ 19.5 _ 53.6 ___ 15.4 _ 3.0 _ 27.8

It indicates fluffy snow that appeared 0.2" deep by ruler but when melted down was less than 0.01" which is a trace of rain too (trace as you know probably is any observation that measures less than 0.05" of liquid. I read a comment on NE forum from somebody in VT saying 7" of snow melted down to 0.20" so at same rate 0.2" would melt to about 0.06" so it must have been even fluffier.

What you need is for weather (snowstorm) here in s/c BC to translate e.s.e. without entirely losing its identity over the plains states as most guidance has been suggesting, and only a shadow of this aggressive system (12" snow in 16h and 5-10 more expected) surviving ... this is because no coherent center of low pressure is able to keep going (on guidance) and the energy almost dissipates before trying to recover over Ohio and s PA on its way to join forces with an offshore low that won't in and of itself be a snow producer, your snow if any would come from any processes within the inland secondary (which is the shadow of this sizeable western snowfall associated with a low tracking east into WA and later ID, then s.e. to WY tonight). You might see 0.5 to 1.5 inches from an inverted trof (Norlun) situation or a weak circulation forming at last minute before being sucked out to sea, or you could see 2-4 inches from a more organized system, top end would be 4-8 inches if my low gets more sustainable beyond about Scottsbluff to Goodland KS and can keep trucking east on I-80 as more than just elevated virga and light snow which is what is being suggested on a lot of guidance now. It's too bad because 90% of lows like this keep an identity and keep going across central plains states. This one seems to be dumping its load over Pac NW and s BC and giving up the fight. Best results for you would be to see models tracking any kind of coherent low east from WY-NE or even CO-KS regions on Thursday into IL-IN by early Friday. I will do a snow dance when I go out to shovel out my car later. (s.o.g. in the bush here is now close to 30" and 25" of it fell since Jan 6, it was quite bare frozen snow before).

12 inches of powder in last 16 hours and looking at 5-10 additional before it shifts southeast. Enjoy.

Snow stopped falling just after end of Tuesday in n.eastern Maine, but here's a roundup of reported values (including Monday Jan 15 where snow or precip began before midnight): JAN 15-16 Snowfalls and Liquid Equivalents Loc ___ snow _ liq.equiv. __ portion on Jan 15 BGR ___ 4.8" (0.39" l.e.) __ plus trace snow Jan 17 CAR ___ 9.0" (0.62" l.e.) __ 10.1" (0.67" counting Jan 17) PWM ___ 2.8" (0.36" l.e.) CON ___ 5.1" (0.41" l.e.) BTV ___ 5.1" (0.20" l.e.) incl (0.1" on 0.01" l.e. 15th) BOS ___ 3.5" (0.56" l.e.) PVD ___ 3.4" (0.75" l.e.) incl (0.1" on 0.01" l.e. 15th) ORH ___ 3.6" (0.46" l.e.) BDL ___ 2.0" (0.31" l.e.) (Tr l.e. 15th) ALB ___ 3.4" (0.25" l.e.) BGM ___ 5.2" (0.21" l.e.) AVP ___ 2.2" (0.19" l.e.) incl (0.2" on Trace l.e. 15th) BDR ___ 2.0" (0.30" l.e.) incl (0.2" on 0.01" l.e. 15th) ISP ____ 2.3" (0.53" l.e.) incl (0.5" on 0.07" l.e. 15th) JFK ___ 2.0" (0.42" l.e.) incl (0.7" on 0.06" l.e. 15th) NYC ___ 1.7" (0.32" l.e.) incl (0.4" on 0.04" l.e. 15th) LGA ___ 2.3" (0.37" l.e.) incl (0.3" on 0.04" l.e. 15th) EWR ___ 2.1" (0.27" l.e.) incl (0.4" on 0.03" l.e. 15th) ACY ___ 1.3" (0.39" l.e.) incl (1.0" on 0.12" l.e. 15th) PHL ___ 3.3" (0.42" l.e.) incl (1.5" on 0.19" l.e. 15th) ABE ___ 3.0" (0.29" l.e.) incl (0.6" on 0.06" l.e. 15th) MDT ___ 3.1" (0.30" l.e.) incl (0.8" on 0.07" l.e. 15th) BWI ___ 4.9" (0.48" l.e.) incl (4.1" on 0.36" l.e. 15th) DCA ___ 4.1" (0.35" l.e.) incl (3.4" on 0.31" l.e. 15th) IAD ___ 4.4" (0.34" l.e.) incl (4.1" on 0.31" l.e. 15th) RIC ___ 0.5" (0.35" l.e.) incl (0.5" on 0.14" l.e. 15th)

Snow stopped falling before end of Tuesday in n.eastern Maine, but here's a roundup of reported values (including Monday Jan 15 where snow or precip began before midnight): JAN 15-16 Snowfalls and Liquid Equivalents Loc ___ snow _ liq.equiv. __ portion on Jan 15 BGR ___ 4.8" (0.39" l.e.) ___ trace snow Jan 17 CAR ___ 9.0" (0.62" l.e.) ___ total 10.1" (0.67" counting Jan 17) PWM ___ 2.8" (0.36" l.e.) CON ___ 5.1" (0.41" l.e.) BTV ___ 5.1" (0.20" l.e.) incl (0.1" on 0.01" l.e. 15th) BOS ___ 3.5" (0.56" l.e.) PVD ___ 3.4" (0.75" l.e.) incl (0.1" on 0.01" l.e. 15th) ORH ___ 3.6" (0.46" l.e.) BDL ___ 2.0" (0.31" l.e.) (Tr l.e. 15th) ALB ___ 3.4" (0.25" l.e.) BGM ___ 5.2" (0.21" l.e.) AVP ___ 2.2" (0.19" l.e.) incl (0.2" on Trace l.e. 15th) BDR ___ 2.0" (0.30" l.e.) incl (0.2" on 0.01" l.e. 15th) ISP ____ 2.3" (0.53" l.e.) incl (0.5" on 0.07" l.e. 15th) JFK ___ 2.0" (0.42" l.e.) incl (0.7" on 0.06" l.e. 15th) NYC ___ 1.7" (0.32" l.e.) incl (0.4" on 0.04" l.e. 15th) LGA ___ 2.3" (0.37" l.e.) incl (0.3" on 0.04" l.e. 15th) EWR ___ 2.1" (0.27" l.e.) incl (0.4" on 0.03" l.e. 15th) ACY ___ 1.3" (0.39" l.e.) incl (1.0" on 0.12" l.e. 15th) PHL ___ 3.3" (0.42" l.e.) incl (1.5" on 0.19" l.e. 15th) ABE ___ 3.0" (0.29" l.e.) incl (0.6" on 0.06" l.e. 15th) MDT ___ 3.1" (0.30" l.e.) incl (0.8" on 0.07" l.e. 15th) BWI ___ 4.9" (0.48" l.e.) incl (4.1" on 0.36" l.e. 15th) DCA ___ 4.1" (0.35" l.e.) incl (3.4" on 0.31" l.e. 15th) IAD ___ 4.4" (0.34" l.e.) incl (4.1" on 0.31" l.e. 15th) RIC ___ 0.5" (0.35" l.e.) incl (0.5" on 0.14" l.e. 15th)

Snow stopped falling just after end of Tuesday in n.eastern Maine, and here's a roundup of reported values (including Monday Jan 15 where snow or precip began before midnight): JAN 15-16 Snowfalls and Liquid Equivalents Loc ___ snow _ liq.equiv. __ portion on Jan 15 BGR ___ 4.8" (0.39" l.e.) __ Tr snow Jan 17 CAR ___ 9.0" (0.62" l.e.) __ total 10.1" (0.67" counting Jan 17) PWM ___ 2.8" (0.36" l.e.) CON ___ 5.1" (0.41" l.e.) BTV ___ 5.1" (0.20" l.e.) incl (0.1" on 0.01" l.e. 15th) BOS ___ 3.5" (0.56" l.e.) PVD ___ 3.4" (0.75" l.e.) incl (0.1" on 0.01" l.e. 15th) ORH ___ 3.6" (0.46" l.e.) BDL ___ 2.0" (0.31" l.e.) (Tr l.e. 15th) ALB ___ 3.4" (0.25" l.e.) BGM ___ 5.2" (0.21" l.e.) AVP ___ 2.2" (0.19" l.e.) incl (0.2" on Trace l.e. 15th) BDR ___ 2.0" (0.30" l.e.) incl (0.2" on 0.01" l.e. 15th) ISP ____ 2.3" (0.53" l.e.) incl (0.5" on 0.07" l.e. 15th) JFK ___ 2.0" (0.42" l.e.) incl (0.7" on 0.06" l.e. 15th) NYC ___ 1.7" (0.32" l.e.) incl (0.4" on 0.04" l.e. 15th) LGA ___ 2.3" (0.37" l.e.) incl (0.3" on 0.04" l.e. 15th) EWR ___ 2.1" (0.27" l.e.) incl (0.4" on 0.03" l.e. 15th) ACY ___ 1.3" (0.39" l.e.) incl (1.0" on 0.12" l.e. 15th) PHL ___ 3.3" (0.42" l.e.) incl (1.5" on 0.19" l.e. 15th) ABE ___ 3.0" (0.29" l.e.) incl (0.6" on 0.06" l.e. 15th) MDT ___ 3.1" (0.30" l.e.) incl (0.8" on 0.07" l.e. 15th) BWI ___ 4.9" (0.48" l.e.) incl (4.1" on 0.36" l.e. 15th) DCA ___ 4.1" (0.35" l.e.) incl (3.4" on 0.31" l.e. 15th) IAD ___ 4.4" (0.34" l.e.) incl (4.1" on 0.31" l.e. 15th) RIC ___ 0.5" (0.35" l.e.) incl (0.5" on 0.14" l.e. 15th)

Snow stopped falling just after end of Tuesday in n.eastern Maine, and here's a roundup of reported values on Jan 15-16 (including Monday Jan 15 where snow or precip began before midnight): JAN 15-16 Snowfalls and Liquid Equivalents Loc ___ snow _ liq.equiv. __ portion on Jan 15 BGR ___ 4.8" (0.39" l.e.) __ trace fell Jan 17 CAR ___ 9.0" (0.62" l.e.) __ 10.1" (0.67" counting Jan 17) PWM ___ 2.8" (0.36" l.e.) CON ___ 5.1" (0.41" l.e.) BTV ___ 5.1" (0.20" l.e.) incl (0.1" on 0.01" l.e. 15th) BOS ___ 3.5" (0.56" l.e.) PVD ___ 3.4" (0.75" l.e.) incl (0.1" on 0.01" l.e. 15th) ORH ___ 3.6" (0.46" l.e.) BDL ___ 2.0" (0.31" l.e.) (Tr l.e. 15th) ALB ___ 3.4" (0.25" l.e.) BGM ___ 5.2" (0.21" l.e.) AVP ___ 2.2" (0.19" l.e.) incl (0.2" on Trace l.e. 15th) BDR ___ 2.0" (0.30" l.e.) incl (0.2" on 0.01" l.e. 15th) ISP ____ 2.3" (0.53" l.e.) incl (0.5" on 0.07" l.e. 15th) JFK ___ 2.0" (0.42" l.e.) incl (0.7" on 0.06" l.e. 15th) NYC ___ 1.7" (0.32" l.e.) incl (0.4" on 0.04" l.e. 15th) LGA ___ 2.3" (0.37" l.e.) incl (0.3" on 0.04" l.e. 15th) EWR ___ 2.1" (0.27" l.e.) incl (0.4" on 0.03" l.e. 15th) ACY ___ 1.3" (0.39" l.e.) incl (1.0" on 0.12" l.e. 15th) PHL ___ 3.3" (0.42" l.e.) incl (1.5" on 0.19" l.e. 15th) ABE ___ 3.0" (0.29" l.e.) incl (0.6" on 0.06" l.e. 15th) MDT ___ 3.1" (0.30" l.e.) incl (0.8" on 0.07" l.e. 15th) BWI ___ 4.9" (0.48" l.e.) incl (4.1" on 0.36" l.e. 15th) DCA ___ 4.1" (0.35" l.e.) incl (3.4" on 0.31" l.e. 15th) IAD ___ 4.4" (0.34" l.e.) incl (4.1" on 0.31" l.e. 15th) RIC ___ 0.5" (0.35" l.e.) incl (0.5" on 0.14" l.e. 15th)

I recall the weather situation around that, in Ontario where I was that winter, we had an extreme cold spell where the temperature stayed below zero F all day. This place where I worked did forecasts for industrial clients relating to air pollution control, so it was rather technical work (telling people if it was going to be safe to operate or would they be killing folks) and not public forecasting stuff, but I recall the low in question passing by to our south and a big warm up that followed after quite a cold February was just about done. I would have to pull some historical weather maps (maybe in article you linked) but I seem to recall a high of around 1055 mbs being involved in the extreme cold. It was so cold we cancelled a planned trip that involved a cross-country ski event around Ottawa where it was looking like -20 F instead of just the balmy zero F we had in Toronto. I don't keep in touch with anyone at Accu-wx but I did meet some very nice people, as well as Joe B. (jk, younger Joe was shall we say an intense weather nerd and not afraid to go against the herd). I was on the technical side, rather than forecasting, but everyone got to chip in on forecast discussions. This is what they would do for every big event -- every person would draw up their own map and then they would put them all up on a wall and discuss. At the end of the discussion they had a consensus forecast. And you know how good those can be. - - - so I looked up the charts and read the article. It was the same set of events, the big high was over Ontario on Saturday 17th and the PD-1 event was on the 19th. I guess it ran into quite a wall of cold air. And that, as the article relates, ended a long cold winter once it played out. I've been very lucky to experience so many big weather events, I was also right in the worst part of the July 1995 derecho event, and actually had the eye of hugo pass over home base in its dying phases. Also some epic lake effect storms and huge snowstorms like 1-23-1966 and the Chicago blizzard a year later but getting both the warm sector and a big chunk of the snowstorm! I guess when I was young I thought the weather was going to stay in that beast mode forever, by around 1986 I was starting to wonder, what happened to our weather machine, this is getting pretty boring now. All the big storms I saw in "formative years" are no doubt a reason why I tend to go for the fences on forecasts sometimes, must be nostalgia overcoming common sense.

It has warmed up to 20F around here and a big dump of snow is incoming, expecting 10-15 inches locally. Deep winter gets deeper.

Looks like a highly variable pattern rather than a big warmup to me, yes there are a few days in 50s but also reloading cold shots on latest run, and end of current run into early Feb looks very similar to Feb 1-3, 1993 when there were a few modestly warm days before a very cold period of six weeks that ended up with the superstorm of march 1993. Also I have seen some similarity of pattern evolution to winter of 1888. It makes me wonder, what is the warmer climate version of blizzard of 1888? Anyway, I would look for some frigid temps at times in February, I don't believe it is going to torch. This coming weekend will be quite cold with 510 dm thicknesses shown over the region on Saturday into Sunday a.m.

True story, I worked at Accu-weather in winter 1979-80 and next desk over was Joe B. It has been downhill ever since (for all of the above? one or two out of three? .. not sayin'). We TOTALLY NAILED the leap year day blizzard of 1980. Again, downhill ever since. It's a good job we did nail it because there was little snow otherwise. I dimly recall a 6" event around mid-Feb in PA ... Lake Placid NY had to run snow making machines full blast to stage the winter Olympics. It was almost as bad as last winter in terms of no snow, until Feb 28-29-mar 1, quite a storm down around Virginia Beach, and record cold in n.e. US, Ontario. At least we didn't have to choose between models, there was just one or two, the LFm Limited Fine mesh (sounds like a porn site, but it was not that kind of model). People say how forecasting has improved but I can recall some very good forecasts made with just the tech of 1970s and early 80s, and the good old LFm. That placed the Cleveland blizzard low (1-26-78) as a 960 mb over Lake Ontario 24h in advance, not quite right, but good enough to warn most affected areas of what was coming. Imagine my surprise on morning of Jan 26 coming into a (private forecasting) weather office in Toronto and discovering it was actually a 955 mb low over w Lake Erie to south end of Lake huron, and London ON was getting a south wind gusting to 90 knots with arctic air wrapping around the center blowing squalls off Lake Erie. We shall not see its like again, I suppose. I knew something was up, we were expecting a snowstorm in Toronto but it was raining and 40F with a very strong east wind at 0800h, and there was an air conditioning unit in my parking space blown off our building, then about 15 min after I got into work and was just looking in awe at the data (teletype), wind shifted to SSW 40 kts and the snow began, so the forecast worked out for wrong reasons in T.O. ... I don't recall if the Ohio blizzard was really nailed by forecasters or not, but from the primitive model of the day, a reasonably close approximation was possible, I would think there was a forecast of an ordinary to severe snowstorm but not the monster that actually hit. I always wonder what the current models would show for 1-26-78, that low was near Atlanta at 00z and deepened 30-40 mbs in only a few hours. I'm pretty sure they would have been a bit closer than Lake Ontario for its 12z position but maybe Erie PA 958 mbs or whatever is 50% better. Those primitive models also told us quite accurately that we would be on the track of Frederic (Sep 1979) and get 4-6 in of rain. Forecasting has not improved very much in my humble opinion, possibly at 3-5 days? But we used to hand draw those progs. And they were often pretty good.

Until Feb 5-6.

Low offshore deepened just enough to push associated 850-925 above freezing temps back to n.w. as it passed, reverse process now underway, soundings showed +1 at 925 and +2 (C) at 850 mbs. Low is not very vigorous so boundary layer inflow was too weak to bring temps up above freezing at surface. General comment, link below is excellent for tracking upper air conditions: http://spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=16&parm=925mb&underlay=1&source=1

It's looking very cold for Saturday mid-day there, temps in low 20s or even high teens. Could be 5-10 F by Sunday morning, below zero in outlying n/w forum areas. As to snowfall, I wouldn't want to guess with the spread in guidance now, looks like about 40% chance of a 0.5 - 2" event, 40% 3-5" and 20% 5+ ... if low just races east from 35N only trough to wNY can produce any snow, if low takes a bit longer to head east, 3-5" and if models just decide to correct north, 10" potential.

Yes, when it gets hot in BC and WA-OR-Idaho dew points can be quite tolerable, low 50s, to near 70 F is range I have seen, when it's 95-100 F with 68-72 dews, people complain of humidity but I moved here from Ontario and I didn't feel the humidity at all when people were complaining about it, it still felt hot and dry to me. Even in the heat dome event, it was basically the same feel that you have in Las Vegas where it can be 115/45. As to the rainfall, we have basically four NW-SE trending ranges to intercept Pacific moisture, Coast-Cascades, monashees (where I reside), Selkirks and Purcells, then the border with Alberta is the Rockies. So five in total, it's a wonder it rains at all in Alberta after these five are done with their orographic rainfall. I would say Coast-Cascades takes almost half, monashees, Selkirks, Purcells and Rockies all take about one-seventh each. It raises rainfalls to 100-120" annually in peak upslope locations in Coast and Cascades, and to 45-60 in totals in prime locations of the other ranges I cited. Valleys get about 10-20 inches and there are some semi-arid landscapes that are not quite desert but dryland similar to the lower areas of central Utah. This monas ee Range is a bit lower than the others but still has so e peaks of 8,000' to 10,000' but it is not as uniformly alpine, so moisture tends to leak through, I am on the dowslope side but we still get about 30" precip and abut half of it falls as snow. Down the hill near the Columbia River it's a lot drier, 12-15" totals, and 30-40" snowfall averages. We were just down there, and while we have a snow pack of two feet here, down in Trail it was about 4" and bare spots on south-facing slopes even in this rigid air mass. These mountain ranges all cross the border. The Cascades of course go all the way to n California. Our Coast Range intersects the Cascades near its northern end, but your Coast Range is an extension of our Vancouver Island mountains. The Cascades continue north for about 50 miles into Canada. East of them is a fairly extensive plateau region, ten the Okanagan valley. That extends south into the U.S. and merges wit the Columbia valley at the Grand Coulee Dam . The monashees extend just into WA state a few miles and more or less disappear as a few minor hills north of Spokane. The Selkirks and Purcells cross the border into n.e. corner of WA and into Idaho, and both disappear for a while before re-establishing as the Bitterroot Ranges which form the border of montana and Idaho. In BC, the trench between Selkirks and Purcells is filled by Kootenay Lake, part of the Kootenai River drainage (spelling changes to Kootenay River in Canada). That river joins the Columbia near YCG (Castlegar) which is fairly close to my location. Then between the Purcells and Rockies is a deep trench, bot Kootenay and Columbia rise in the Rockies, and flow in opposite directions from a point (Canal Flats) where a lake actually joins their drainages. The Kootenay goes south into montana and picks up several large tributaries in w montana, and also the Pend d'Oreille which drains lakes in n. Idaho, and flows just into BC before hitting the Columbia at the border. That trench between Purcells and Rockies is known as the East Kootenay and the region around Kootenay Lake and the lower Columbia is the west Kootenays. Anyway, that trench is semi-arid around Cranbrook and further south into montana, but it becomes a temperate rain forest further north where the Selkirks, Purcells and Rockies more or less merge into just the Rockies north of about 51 deg N. So further north in BC, the Pacific moisture is contending only with the Coast Range and a few bumps in an extensive plateau before hitting the Rockies. A lot more moisture makes it all the way, so rain forest can be found well out into the plateau to the west of the Rockies in central BC.

I believe this one will overperform and give widespread 5-8 in snowfalls, local 8-12 near Gulf of maine north of BOS. Reason is cold air will also overperform setting up ahead of sliding frontal wave, and force it to develop a bit more. Temps will be 18-22 F during snow any distance inland and 24-28 F near coast. Only Cape Cod and islands will see any taint or mixing. Not that 5-8 inches is any big deal, but whatevs. Also, look for several big storms in Feb and march , this winter is going to become more intense. I believe the polar conveyor belt (NNW-SSE) is setting up for repeated delivery, and Pacific will fight back enough to knock it eastward so that it isn't wasted on my part of the world at all. It looks like a sort of 2008 blend with 2010 and a bit of the old 1888. Watch out for march 10-12. Not saying it will never turn warm, but warm spells will be very brief and quickly flushed out.

Just for record, -44 at Glasgow and -43F at Jordan, montana, were lowest min I could find in lower 48 so far (for Sunday a.m.) ... lows into -40s in Alberta and -50s F north of Edmonton (-59 F in n.w. Alberta at Keg River). As cold as that sounds, it was -74F in 1947 at Watson Lake in southeast Yukon. At my location, Friday and Saturday were exceptionally cold, it moderated a little today. I don't maintain records but based on nearby stations and usual differentials, it was about -32 C (-25 F) overnight, and -5 F for daytime maxima (about +7 F today). We have ice crystal fog and saw low-altitude sundogs from the ice crystals. Deep winter and another snowfall of 15-20 cms expected midweek during moderation to 25-30 F.

So far, coldest overnight low I can find in U.S. (at a weather station) was -43 F at Jordan, montana. There have been several near -50 C (-58 F) in western Canada past two days. Just noted -50.6 C at Keg River Alberta early today (-59 F).

GFS looks like 1.5 to 3.0 in w temps in 20s.