I am currently in Boston and watching the Weather Channel  where there is a lot going on weatherwise here atm.

Winter storm Aubrey is giving heavy snow in the northern plains with Fargo progged to get 24 to 36 ins in the next day or two. Denver has gone from 84F to 23F in one day. Ahead of the cold front there are tornado warnings around oklahoma  City.

In my neck of the woods it is very windy but the rain is holding off. This is a seperate system spinning up off the Eastern Seaboard giving a claasic nor easter in SE New England.

Last but not least California has a Santa Ana with an extreme fire risk 

Even the Weather Channel are struggling to decide which to talk about

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Spoke to my project team in Denver at 4pm UK/ 9am Mountain time today and it was snowing and settling but melting quite quickly. Obviously heavy enough precipitation to settle even with the warm ground temps. Temps were around -2c at that time. The team in Austin and Bangalore were not jealous!

 

Look at Denver webcam - the snow is actually settling!?

 

Crazy given as you said it was 27c/28c yesterday !! One would have thought the ground surface temps would be way too warm for any snow to settle?? So odd?? well, i never?? Bare in mind 28c would feel hotter due to it's altitude - so for all this snow to settle and build up so quickly??? how the heck does it work? I am thinking maybe the precipitation must have been so heavy but then again....!?? if ground surfaces temps are so warm or hot...how is this possible people?? pavements , roofs etc...? surely they must have been hot after yesterdays record breaking heat? - all that's happened is that the air temp has dropped 33c in 24 hours but wouldn't have given enough time for the ground surface temperatures to cool down!!

Tierradelfuego - you could be right! - very heavy blizzard whiteout conditions! surely for snow to settle on such warm surface temps - must have been a slush-fest at first surely!? ha~!

ANyway, snow melting tomorrow and then 71 F (22c) by Saturday and Sunday!

Here with live Denver webcam:

https://www.earthcam.com/usa/colorado/denver/?cam=denver

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The surface heat will radiate very quickly at altitude under clear skies. You can feel the difference in this country on a clear autumn afternoon, when that sun drops you notice the chill.
That said in America the contrasts between temperatures can be amazing.

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Some amazing figures have come out - Like from 28C to -10C in less than 24 hours.

 

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Serious early blizzard in North Dakota
They haven't been able to get on with corn (maize) harvest yet and cattle are still out in this with little feed available.
https://twitter.com/pollypencilplow/status/1183838946150760448?s=20 

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Good videos Four 

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Eastern US setting early season Low temp records a few days ago. Link has nice videos of 'sea smoke'

https://www.wunderground.com/cat6/Eastern-US-Deep-Freeze-Venice-Hit-Second-Worst-Flooding-Record

immediately followed by an east coast storm. Who needs hurricanes when you can have one of these?

https://www.wunderground.com/cat6/Flanking-US-East-Coast-Storm-Weekend-Wet-Southwest-Low-Next-Week

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 https://www.weathernationtv.com/news/alaska-drops-to-65-degrees-friday/

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No one is talking about the exceptional warmth up the eastern seaboard and this contrast/gradient will more than likely add more fuel to the jet:

21c currently at 2pm GMT: - Temps in DC are not expected to dip much below 20c (70'F) tonight in DC area.

https://www.accuweather.com/en/us/washington/20006/weather-forecast/327659

Temps in New York city are 19c.

What's the January record warmth for both major cities?

EDIT: Found it here:

https://www.accuweather.com/en/weather-news/record-challenging-warmth-to-thaw-wintry-northeast-this-weekend/659224

 

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No one is talking about the exceptional warmth up the eastern seaboard and this contrast/gradient will more than likely add more fuel to the jet:

21c currently at 2pm GMT: - Temps in DC are not expected to dip much below 20c (70'F) tonight in DC area.

https://www.accuweather.com/en/us/washington/20006/weather-forecast/327659

Temps in New York city are 19c.

What's the January record warmth for both major cities?

EDIT: Found it here:

https://www.accuweather.com/en/weather-news/record-challenging-warmth-to-thaw-wintry-northeast-this-weekend/659224

 

Whilst it's 18c to 20c up the eastern seaboard of the USA including far eastern Canada during early hours - look how cold it is across the north of Canada - Yellowknife, DOC? 

It's -43c in Yellowknife: The January average is around -23c so temperatures are some 20c below average in Yellowknife!

 

 https://www.theweathernetwork.com/ca/weather/northwest-territories/yellowknife

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https://weather.gc.ca/city/pages/ab-52_metric_e.html 

Some frigid air across Alberta this week...Even Vancouver gets in on the action with daytime maxes of -5℃...

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Looks like Denver will encounter one of its spectacular temperature fluctuations early next week...A high of 21c on Sunday ...down to an overnight low of -17c Tuesday night .

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Some serious heat across parts of SW USA this weekend..LA has a high of 42c tomorrow...
But as always the mile high city takes the phenomenon stakes again..Max temp there is as follows over the next 4 days

Today high 38c
Sunday high 37c
Monday high 34c
Tues high 5c....with sleet

Quite amazing even for Denver

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Some serious heat across parts of SW USA this weekend..LA has a high of 42c tomorrow...
But as always the mile high city takes the phenomenon stakes again..Max temp there is as follows over the next 4 days

Today high 38c
Sunday high 37c
Monday high 34c
Tues high 5c....with sleet

Quite amazing even for Denver

An incredible drop in temperature.  I notice also that parts of Arizona and California will be in the High 40s today and Death Valley could exceed 50C again over the Labor Day weekend.  Surely some date records must fall. 

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How a pair of Typhoons 6000 miles away (only 1 is pictured here) is helping to magnify the already amplified pattern enhancing historic heat in CA and produce cold and snow in Denver. Lesson: It's all connected and every action has an opposite reaction. pic.twitter.com/Ot9GTjy3ws

— Jeff Berardelli (@WeatherProf) September 4, 2020

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Some serious heat across parts of SW USA this weekend..LA has a high of 42c tomorrow...
But as always the mile high city takes the phenomenon stakes again..Max temp there is as follows over the next 4 days

Today high 38c
Sunday high 37c
Monday high 34c
Tues high 5c....with sleet

Quite amazing even for Denver

Looks like the temp could get close to 0c with the prospect of settling snow on some higher surfaces, the ground would likely still be very warm though .

Was looking at the 850hpa temps and then realised they were pretty meaningless for that area give the altitude.

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Some serious heat across parts of SW USA this weekend..LA has a high of 42c tomorrow...
But as always the mile high city takes the phenomenon stakes again..Max temp there is as follows over the next 4 days

Today high 38c
Sunday high 37c
Monday high 34c
Tues high 5c....with sleet

Quite amazing even for Denver

Beeb now as 35c Monday and double snow and 5c to -1c Tuesday never seen anything so extreme before.

 

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Thanks for bringing this thread back to life - I couldn't find it anywhere, so will post on here - Despite looking and the action is all in the USA right now!

Denver for starters - Going from record breathtakingly high to a record breathtakingly low temperature and perhaps earliest snowfall ever!?

https://weather.com/weather/tenday/l/Denver+CO?canonicalCityId=9298101d6fcde701a8dae5f27c875376e208cae14ce31a258c225f63573146be

Interesting how it can go from one extreme to another - i remember extremes in Calgary, Canada but this extreme tops it!
How the do people cope with this sudden change? The must go to bed feeling hot and bothered using the air con or having all the windows open and then must have to set their alarms to wake up half way through the night to turn heating on and turn off the air con and close all windows!? Only to find out they wake up to snow on the ground the following morning A 30c or 35c drop in temperature in less than a day must be difficult to adapt to!? hmm! How erratic. Result of being 1 mile high I guess?

Going from +35c Monday 7th Sept to a high of -2c on Tuesday 8th Sept with snow accumulating up to 10-15cms.

 

Surely if the temperature has been well into the plus +30c for weeks on end how would snow settle? Anyone? Wouldn't the ground be too warm?

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