 Poster: A snowHead
|
Some very cold air courtesy of the Polar Vortex is working it's way down South. Looks like some promising storm activity will meet up with the Polar Vortex and violate COVID social distancing rules and drop some cold smoke pow across a wide swath of the PNW into Tetons, Wasatch and Colorado Rockies.
|
|
|
|
|
|
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
|
@Toadman, Finally, the normal La Nina effect for NA. With some spice from the third SSW episode 
|
|
|
|
|
|
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
|
Have heard on the weather reports that there was a very high mb reading some where above the Arctic Circle of AK recently.
Some serious storm activity for the New England and Upper Midwest states with -50F wind chills this week too.
We need snow in my home state of Oregon. We are currently about 85% of normal water equivalent snow pack. Lots of little storms with small accumulations this season. But no really big events. Hopefully this storm delivers for us.
But this is that La Nina weather pattern that can develop in February with moist low pressure troughs coming off the Pacific that mix with cold Arctic air.
|
|
|
|
|
|
You need to Login to know who's really who.
You need to Login to know who's really who.
|
|
|
|
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
|
|
|
|
You'll need to Register first of course.
You'll need to Register first of course.
|
Explanation in layman's terms please!
We're in Briançon, France, 1200m approximately. Wettezentrale gives 2m temp of -18 degrees on Sunday, but 850 hpa temp of -11 degrees.
As I understand, 2m temp is measured 2m off the ground (so 1202m?), so should be warmer than 850 hpa temp which is measured at 1500m?
Which should I be using?
Ta 
|
|
|
|
|
|
|
|
| Quote: |
| so should be warmer than 850 hpa temp which is measured at 1500m? |
Temperature inversion maybe: often colder in valley than at altitude
|
|
|
|
|
|
|
|
| KenX wrote: |
| 850 hpa temp which is measured at 1500m? |
I don't think this is (necessarily) correct. I think the 850hPa level is however high above sea level that specific air pressure happens to be. That might on average correspond to 1500m but I think it varies quite a lot (presumably depending at least partly on how high or low the air pressure is in the region!).
If the general air pressure is low, I guess the 850hPa altitude would be higher than usual. Whereas in anticyclonic conditions, the 850hPa altitude would be lower.
It makes it quite tricky to directly extrapolate ground level temperatures from 850hPa values.
|
|
|
|
|
|
You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
|
|
So is the 2m temp the more reliable?
|
|
|
|
|
|
|
|
@KenX, not sure which is more reliable, but I imagine they have different purposes, eg 2m is a proxy ground temp (less extreme than actual surface temp). For snow forecast reliability I'd always look at the 850hpa level, which is a more stable indicator of airmass temp at roughly 1500m (not worrying about the technical difference in whether it's actually 1400m or 1600m because the margin for error in snowline is pretty wide anyway).
So for sunday it looks like temp inversion most of the day, apart from lunchtime when the effect of the sun is strongest. Looking at PdS 1200m, the 850hpa temp is stable at roughly -8c for 20 hours, while the 2m temp goes from -16c overnight to -5c at midday and then -13c into monday night.
I suspect there is an issue with models and the timing of their snow forecasts, in that they seem to over-estimate snowfall during the day and underestimate evening / nighttime snowfall.....just a hunch but maybe the models rely too much on 850hap temps and not the more variable 2m temp.
So model resolution (grid size) and topography aside, I'd say 2m is more reliable for how it will feel, and the quality of snow. Whereas 850hpa is a better indicator for snowline. I could be wrong
The 15/16th looks pretty settled in the west now, no sign of any undercut....so the mean charts were more reliable in this instance.
Scandi high pressure is hard to shift though, so maybe there will be a second attempt at undercut around 21-22 feb. But beyond this week it is looking very dry and trending back towards average temps in the NW
|
|
|
|
|
|
snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
|
Thursday could be a day for slightly sickening webcam watching in the uk. The air should be clear and very cold everywhere. Down below minus 20c at Braemar 
|
|
|
|
|
|
And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
|
|
Snow has arrived for the PNW. Working it's way through the Sierra's as well. Going to be a good few days for a whole bunch of ski resorts in multiple states over the next 4-5 days.
|
|
|
|
|
|
|
|
| Toadman wrote: |
| Snow has arrived for the PNW. Working it's way through the Sierra's as well. Going to be a good few days for a whole bunch of ski resorts in multiple states over the next 4-5 days. |
Storm came in late and a bit scattered and without much energy. Some warm air that was in place seems to have been pushed up as the cold air came in from the North causing an inversion for the South Cascades. For the North Cascades the cold air was already in place but not much moisture.
Shoveling the sidewalk this morning was quite easy as the snow was dry and light. Not so for the ski resort with heavier snow and temps that were about 7 degrees warmer.
The next wave is coming in later tonight, but that too is coming in behind the original forecast from 48 hours ago. Possibly it stalls out as it arrives with some NW flow coming out of Northern Cali and meets up with the colder SW flow. Still looks like they are calling for anywhere from a foot to two feet between Friday night into Sunday morning for the Central and South Cascades.
Montana ski areas closed on Friday due to Arctic temps in the -20f-25f range and wind chills to -50f. Brrrr!!!
Jackson Hole and Sun Valley should also see a foot or so as the PNW storm works its way East over the weekend.
|
|
|
|
|
|
You know it makes sense.
|
|
Very jealous of you guys in north america. In Europe spring starts next week...
|
|
|
|
|
|
Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
|
|
|
|
Poster: A snowHead
|
|
|
|
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
|
|
|
|
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
|
| Charlieehr wrote: |
| Very jealous of you guys in north america. In Europe spring starts next week... |
Depends on where you are at.
I guess Texas is going to be colder than Switzerland.
https://news.yahoo.com/us-cold-snap-why-texas-181730836.html
The state is seeing some of its coldest temperatures in more than 30 years, with some areas breaking records that are more than a century old.
Parts of Texas hit 0F (-18C) on Sunday, and weather warnings are going to stay in place through the week.
According to the US National Weather Service (NWS), this is down to an "Arctic outbreak" that originated just above the US-Canada border, bringing a winter snow storm as well as plummeting temperatures.
Cold air outbreaks such as these are normally kept in the Arctic by a series of low-pressure systems, the NWS said. However, this one moved through Canada and spilled out into the US last week.
Temperatures in the city of Dallas for example will reach a high of 14F (-10C) on Monday when it should be more like 59F (15C) at this time of year.
For the first time in the US state, all 254 counties are under a winter storm warning, US media report. The temperature in Dallas is already colder than in Anchorage, Alaska, CBS News reports.
|
|
|
|
|
|
You need to Login to know who's really who.
You need to Login to know who's really who.
|
|
Looking like Quite a flip to late spring weather by the end of February. Freezing level potentially well above 3000m.
|
|
|
|
|
|
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
|
More storms rolling in off the Pacific for North America. The Polar Vortex has made its way down to the Mexico border. I don't believe Trump's wall will stop it if it decides to continue heading South. But, it appears to be headed NE toward the New England states after dropping the temps from Texas all the way through Oklahoma, Tennessee and up through Pennsylvania and into New England.
Mt Baker hit 500" (12.7 meters) for the season already. Cascades are finally back to about normal snowpack for this time of year.
|
|
|
|
|
|
You'll need to Register first of course.
You'll need to Register first of course.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
|
"Spital am Semmering" @ 800m is closest to Stuhleck (circa 1800m)
|
|
|
|
|
|
|
|
| DB wrote: |
"Spital am Semmering" @ 800m is closest to Stuhleck (circa 1800m)
|
Perfect. Thanks
|
|
|
|
|
|
snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
|
|
|
|
And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
|
Insane nukeage going on in Little Cotton Wood Canyon, UT past 48 hours. 61" snow past two days. Lots of large natural slides, closing the road (210) up the canyon. Scroll down the feed to see some of the vids and pics on the conditions and extreme avy danger.
https://twitter.com/UDOTcottonwoods/status/1362142485057658880
|
|
|
|
|
|
|
|
|
|
|
You know it makes sense.
|
Spring is here in the West Alps... sun feels a nice on the skin tbh, but I was hoping for some more powder turns this season... Is this super-warm-wave likely to stay for march? 
|
|
|
|
|
|
Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
|
|
@Weathercam, we literally had the same concern at the exact same time.
|
|
|
|
|
|
Poster: A snowHead
|
|
|
|
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
|
Just seen this.....
>> Sable du SAHARA, le retour !
En effet et selon toute vraisemblance, un nouvel épisode de poussière désertique est à attendre dès dimanche soir et jusqu'à mardi au moins sur les Alpes-du-Sud.
À nouveau, la concentration en sable pourrait être importante mettant à mal le manteau neigeux.
Ce sable pourrait ensuite rester en suspension dans l'air une partie de la semaine prochaine dans des quantités moindres.
@Charlieehr, was that you yesterday going to clamber up that couloir outside Cervieres?
And @polo, likewise, my OH and daughter back in the UK have now done 50 consecutive days in the sea!
|
|
|
|
|
|
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
|
| Quote: |
@Charlieehr, was that you yesterday going to clamber up that couloir outside Cervieres?
|
Sadly I wasn't  @Weathercam, I was the guys sitting at his desk for 40 hours straight haha.
And sand is back here indeed...already looking quite martian.
|
|
|
|
|
|
You need to Login to know who's really who.
You need to Login to know who's really who.
|
|
|
|
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
|
|
@polo, Blimey I’ve been waiting for this worry , in a normal year this thread goes into meltdown if we have an anticyclone over the alps for two to three weeks somewhat quieter because of the circumstances. If I could I would have returned from a great half term weeks skiing in perfect sunshine with the crowds dispersed over the mountain rather than contained because of bad weather , perfect . Of course the seasons not over , March can always be a snowier month and with this season being in the cold side I suspect we will have a sting in the tail to come .
|
|
|
|
|
|
You'll need to Register first of course.
You'll need to Register first of course.
|
Forecast shaping up for some decent snow accumulation over the next 48 hours in the PNW. AR with some cooler temps = copious amounts of snow. Maybe a meter between Thursday night into Saturday for the North, Central and South Cascades.
Already quite a bit in the mountain passes East of Seattle.
https://twitter.com/SnoqualmiePass/status/1364721477254213640?s=19
|
|
|
|
|
|
|
|
@Rob Mackley, yep this dry spell is gonna stretch over a month in most places, we've seen anticyclones last 6 weeks in bad years, but this year of course had a very good dec and jan so I guess it balances out.
@Toadman, nice avi blast vid....took out a lot of trees and made a new piste 
Here's the latest model output..
Day 6, good agreement for high pressure to amplify NW towards Greenland / Iceland, but europe still blocked, here's UKMO
Day 8/9, cold air arrives from the NE, again decent agreement given the lead time....best is ECM
Day 10 and beyond...
ECM 00z keeps a ridge to the west and a very cold NE flow to the alps (coldest)
GEM 00z flattens the high, bringing in strong NW flow (snowiest)
GFS 00z halfway house, leaves alps stuck under high pressure (worstest)
|
|
|
|
|
|
|
|
We still have sand in the air and a pollution alert in the isere
This was Wednesday morning
It is like April here, 20C+ in the valleys, the days are quite short but the problem with spring snow in February is that it goes from dangerous ice to mushy mush very quickly. Season is dead below 1400 meters, there is still some base above but it depends how long the heatwave and drought lasts. Quantity of new ski tourers and lack of options means more and more people chasing less and less snow.
Still there's always cycling, like last year.
|
|
|
|
|
|
You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
|
| davidof wrote: |
.....Season is dead below 1400 meters, there is still some base above but it depends how long the heatwave and drought lasts. Quantity of new ski tourers and lack of options means more and more people chasing less and less snow.
Still there's always cycling, like last year. |
Yes as above, though I've not been out on the XC trail in the valley to see how that's been holding our this past week.
If we do get snow and temps are not really cold then that new snow will disappear really fast.
South facing slopes with the sand now are just a nightmare the way the melt is occurring, the equivalent of sastrugi.
|
|
|
|
|
|
|
|
|
February has been a good month for many BC and PNW ski areas reporting over 3 meters of snow fall during the month. More on the way to end the month.
|
|
|
|
|
|
|
|
FAQ
) .....they were swimming in snow storms at one point.
