Summer is coming ... [a weather thread]

[Tender Branson]

We already got some snowfall over the past weeks and the mountains are already really white, with some 1-3 feet of snow up there (plus some snow down in the valley). Many ski resorts have already opened or will over the next days. It was also quite cold recently.

And now, there's a major snowstorm coming over the next days:

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https://www.accuweather.com/en/weather-news/disruptive-snowstorm-to-spread-from-austria-to-poland-and-baltic-states/70003397

[wxtransit]

Yay! Snow in Poland...I wish I was there. Back in Texas we're expecting a cold front next week, but no precip behind it. Right now we have above-normal temperatures in the 60s and 70s (fahrenheit) or about 15 to 21 degrees Celsius.

[Tender Branson]

Yay! Snow in Poland...I wish I was there. Back in Texas we're expecting a cold front next week, but no precip behind it. Right now we have above-normal temperatures in the 60s and 70s (fahrenheit) or about 15 to 21 degrees Celsius.

We had about -5°C in the morning (= 20°F).

Once the snowstorm is over on Sunday/Monday, I'll probably go snowshoe hiking the first time this winter season next Friday (a holiday here). Usually, the weather gets much better after a snowstorm and if blue-sky, the temps are dropping to -10°C because of it (10-15 °F).

Perfect weather for skiing/snowboarding or snowshoeing through the woods in the thick powder snow ...

[Mike88]

At least you have snow, Tender. Here we have cold temperatures, around 14º C and 5º C, but, no snow or rain, and when it rains it's just for a few hours. 94% of the country is in extreme drought.

[Tender Branson]

At least you have snow, Tender. Here we have cold temperatures, around 14º C and 5º C, but, no snow or rain, and when it rains it's just for a few hours. 94% of the country is in extreme drought.

I know. I have seen the reports about the wildfires and the situation is bad.

Here, climate change is also visible:

The ZAMG, the weather and climate tracking agency, shows temperature/precipitation changes on a daily/monthly/seasonal/yearly level - compared with the long term averages.

The year 2017 so far is 1.7°C hotter than the average between 1960 and 1990 (the Alpine West is even hotter), but precipitation is about the same as the long term average.

The Fall 2017 was a bit colder so far, but the year started very hot so it cannot be made up anymore.

Climate change is especially visible at the glaciers here - which are retreating at an alarming rate. Most might be gone by 2050, increasing the soil erosion on high-alpine terrain, which can be dangerous to hikers. Previously, there would always be permafrost on high altitudes - even during the summer months, but not any longer: hikers could be killed by huge stones that become loose.

[America's Sweetheart ❤/𝕿𝖍𝖊 𝕭𝖔𝖔𝖙𝖞 𝖂𝖆𝖗𝖗𝖎𝖔𝖗]

Here it doesn't even feel like winter yet, really.

[Ban my account ffs!]

Winter is coming to the U.S. as well.  The signs are there for a period of serious fun and games.

These are the analogs.  The model finds dates with similar weather patterns to what it expects and blends them together by rank and provides a correlation between what it expects and the blend of dates.  

The forecast date from the model is 11 days out on December 9th.


The years/dates here indicate major cold air coming into the central and eastern U.S.  1989 was particularly bad in the east, and shows up multiple times.  2009 has also been showing up a lot, which was the year of Snowmageddon.

What the model actually expects is even more extreme than the blend of analogs with massive blocking (high pressure that causes the jet stream to buckle and fold, sending warm air to the Arctic and cold air to the mid latitudes).



Unlike the past 2 winters, the polar vortex is completely breaking apart into multiple pieces.  You see the - north of Lake Superior... that is a piece of the polar vortex with another piece in the far north Atlantic and also near far eastern Russia.

In warm patterns like the past 2 years, the polar vortex is stronger and centered often times over far northern Canada.  This keeps cold air out of the mid-latitudes.

You also see the blocking highs indicated with +.  One is just off California (remember 'the warm blob'?).  Another is just off of SW Greenland.  This opens the flood gates for cold to move down the prairies/plains and spread across the eastern U.S.



This pattern would mean nasty wintry weather in the eastern U.S. as well as northern Europe, especially around Scotland.  Storms will move directly across the British Isles but there will be lots of cold air available to turn things wintry.

[Ban my account ffs!]

Compare the last graphic above to the forecast for 3 days out.


The jet stream is very flat and "zonal" (west to east) across North America while there is blocking in Europe, hence the storm Tender is talking about.

A zonal pattern keeps the nation flooded with mild Pacific ocean air rather than Arctic air and storms move quickly and cannot gather strength, so the east becomes very mild and dry.  In such a pattern only the Pacific Northwest gets any inclement weather.

Also note how the polar vortex will move from the far north of Canada to almost being centered on Lake Superior.  This is an even bigger displacement than 2013/14, though the potency of the cold air can vary and may not be like that year.

[HillGoose]

Move to the 305, I hear Mr. Worldwide said there's no winter there.

[dead0man]

it was 70 and sunny yesterday, don't get a lot of days like that between Thanksgiving and the 1st of March in Omaha.

[bagelman]

it was 65 and sunny today, not supposed to get a lot of days like that between Thanksgiving and the 1st of March in Cleveland-Akron.

[100% pro-life no matter what]

68 and sunny in TN today.  That's mild, but not record-breaking or anything here.  The past two winters (Dec, Jan, and Feb) have seen more than one-in-six days top 70 degrees, but 2014-15 was the opposite, with no day getting to 70 in those three months.  It's very rare, though, that we get multiple weeks in a row where you can never wear shorts and short sleeves.  This whole week pretty much looks like 60s.

[wxtransit]

Winter is coming to the U.S. as well.  The signs are there for a period of serious fun and games.

These are the analogs.  The model finds dates with similar weather patterns to what it expects and blends them together by rank and provides a correlation between what it expects and the blend of dates.  

The forecast date from the model is 11 days out on December 9th.


The years/dates here indicate major cold air coming into the central and eastern U.S.  1989 was particularly bad in the east, and shows up multiple times.  2009 has also been showing up a lot, which was the year of Snowmageddon.

What the model actually expects is even more extreme than the blend of analogs with massive blocking (high pressure that causes the jet stream to buckle and fold, sending warm air to the Arctic and cold air to the mid latitudes).



Unlike the past 2 winters, the polar vortex is completely breaking apart into multiple pieces.  You see the - north of Lake Superior... that is a piece of the polar vortex with another piece in the far north Atlantic and also near far eastern Russia.

In warm patterns like the past 2 years, the polar vortex is stronger and centered often times over far northern Canada.  This keeps cold air out of the mid-latitudes.

You also see the blocking highs indicated with +.  One is just off California (remember 'the warm blob'?).  Another is just off of SW Greenland.  This opens the flood gates for cold to move down the prairies/plains and spread across the eastern U.S.



This pattern would mean nasty wintry weather in the eastern U.S. as well as northern Europe, especially around Scotland.  Storms will move directly across the British Isles but there will be lots of cold air available to turn things wintry.

I applaud your use of the CPC.

[Lachi]

We're expecting around 150-250 mm (6-8 inches for you imperial freaks) of rain over the weekend in North East, and North Central Victoria. We could get over 100 mm (4 inches) in one day on Saturday.

This is after 18 days of temperatures above 25C, and 14 of above 30C.

This is being caused by a massive amount of humid air coming down to Victoria, and moisture from a cyclone in the north west colliding with a deep low pressure system which already has a heap of moisture in it to begin with.

http://media.bom.gov.au/releases/400/significant-widespread-rain-and-thunderstorm-event-to-affect-multiple-states-this-weekend/

[wxtransit]

Looks like this front early next week will be a bit more powerful than previously thought...might put us below freezing for a few nights in a row. Also, a small chance of precip after the front on Tuesday. High pressure up in Washington and SC might help funnel this toward us.
 

[Ban my account ffs!]

The analogs today are all heavy hitters for a severe Arctic outbreak across the eastern US.  1976, 1985, 1989, 2002.  1976 and 1989 feature most prominently.  Those were brutal years.  The former winter triggered hysteria about a coming ice age and December 1989 smashed cold records on the east coast.

[Ban my account ffs!]

The cause has had long range forecasters foaming at the mouth because the early indications have been strong with a large early season "Sudden Stratospheric Warming" where a massive bubble of warm air settles over the Arctic in the stratosphere, squashing the troposphere, thus "squeezing" the cold air away from the pole into the mid latitudes. 

[MasterJedi]

The analogs today are all heavy hitters for a severe Arctic outbreak across the eastern US.  1976, 1985, 1989, 2002.  1976 and 1989 feature most prominently.  Those were brutal years.  The former winter triggered hysteria about a coming ice age and December 1989 smashed cold records on the east coast.

I'll take -20 all winter if it means no snow lol

[Tender Branson]

The snow is here:



About 8 inches down in the valley so far, about 1-2 feet on the mountain ski resorts.

[Tender Branson]

Currently, we have -10°C (= 14°F) here and no clouds.

Doing some grocery shopping and then a morning walk through the woods. There's also a nice 10 inch layer of snow right now.

[wxtransit]

This cold front will be quite unpredictable for Texas, could see snow in the Panhandle if it is strong enough/with enough gulf moisture, but if it is too weak we could see near-normal temps (40s-50s, about 4 to 10 C) and rain.

[Terry the Fat Shark]

Looks like the first official freeze of the season will come for DFW, if you believe the EURO model.

[Dr. MB]

Last year we had two major (well, by Pacific Northwest standards) snowstorms. That first day, when it started snowing, it took me 2 hours to drive what would normally take maybe 10 minutes. I’m walking if that happens again.

[Terry the Fat Shark]

Last year we had two major (well, by Pacific Northwest standards) snowstorms. That first day, when it started snowing, it took me 2 hours to drive what would normally take maybe 10 minutes. I’m walking if that happens again.

ahhh I was in Salem for those, it was pretty fun (well being that I wasn't stuck in the Portland metro area lol) I remember quite a few including when Portland got 1-2 feet of snow.

[Tender Branson]

Currently, we have -10°C (= 14°F) here and no clouds.

Doing some grocery shopping and then a morning walk through the woods. There's also a nice 10 inch layer of snow right now.

A small collection of pictures:











Tender - The Man at the High Castle: