Model output discussion - 7th January onwards

[feb1991blizzard]

A few GEFS members going sig below -10c now as well.

[SLEETY]

8 minutes ago, feb1991blizzard said:

Did you find out if the year was 1895 btw?

No I think it was earlier, but website that showed it has gone if the trend in the models continue we could be looking at a severe February like 1947,or1895, hoping. The cma Chinese model is very similar to ecm too from its 12z run

Edited January 16, 2019 by SLEETY

[snowray]

GFS 18z ensembles, what a mess!

It will smell the coffee soon enough no doubt!

Edited January 16, 2019 by snowray

[Roger J Smith]

The running CET for Feb 1895 was --4.3 C as late as 14th and 15th. For 1855 it was --3.1 C by the 20th. These months were only passed by 1947 on the last day or so, when that year set the lowest February CET of --1.9. The cold spell in Feb 1895 set several daily records below -7 and lost one when it failed to overcome the -8.8 from 1816 (but that was in a much shorter cold spell). 

[SLEETY]

6 minutes ago, SLEETY said:

No I think it was earlier, but website that showed it has gone if the trend in the models continue we could be looking at a severe February like 1847,or1895, hoping. The cma Chinese model is very similar to ecm too from its 12z run

The gfs ensembles are trending lower, forget minus 10,the minus 15 hpa line is the new form horse

[SLEETY]

3 minutes ago, Roger J Smith said:

The running CET for Feb 1895 was --4.3 C as late as 14th and 15th. For 1855 it was --3.1 C by the 20th. These months were only passed by 1947 on the last day or so, when that year set the lowest February CET of --1.9. The cold spell in Feb 1895 set several daily records below -7 and lost one when it failed to overcome the -8.8 from 1816 (but that was in a much shorter cold spell). 

Do you know the Feb that had a mean temp. Of minus 6.6c for first half . Might be getting near that this month if this trend continues. 

[Bruegelian]

I believe the JMA long ranger was painting quite an extreme picture for February, with easterly winds all around the globe at say 50 degrees north. 

[snowray]

2 minutes ago, SLEETY said:

The gfs ensembles are trending lower, forget minus 10,the minus 15 hpa line is the new form horse

Yes but they are quite frankly all over the place, so pretty useless.

[Roger J Smith]

26 minutes ago, SLEETY said:

Do you know the Feb that had a mean temp. Of minus 6.6c for first half . Might be getting near that this month if this trend continues. 

I have worked out the lowest running values from the daily data and that -4.3 is the lowest (for 1-14 or 1-15 Feb). You can find the coldest weeks on record in my post in the historical weather section (the 2012 edition, has not been updated to the 2018 edition yet). Maybe what you saw was an average for the core of the 1895 cold spell because it wasn't extremely cold for the first few days. Certainly the second week would have averaged close to -6.6 though.

For late January cold, 1776 had a week that averaged -6 C and still holds all daily records for 27th to 31st. 1795, 1881 and 1963 had some very low average values for consecutive days in late January also. I think the bottom line is that this cold spell on some guidance is approaching those limits and the absolute limit must be the -12 C that was the coldest daily mean on record in Jan 1838. That was on the 20th. 

[Roger J Smith]

A link to the coldest weekly values is here:

https://www.netweather.tv/forum/topic/73431-daily-cet-average-values-1772-2011/?page=4

I checked and the lowest weekly average was 6-12 Feb 1895 at -6.3 C. There are slightly colder weeks from Jan 1881.

[SLEETY]

44 minutes ago, Roger J Smith said:

I have worked out the lowest running values from the daily data and that -4.3 is the lowest (for 1-14 or 1-15 Feb). You can find the coldest weeks on record in my post in the historical weather section (the 2012 edition, has not been updated to the 2018 edition yet). Maybe what you saw was an average for the core of the 1895 cold spell because it wasn't extremely cold for the first few days. Certainly the second week would have averaged close to -6.6 though.

For late January cold, 1776 had a week that averaged -6 C and still holds all daily records for 27th to 31st. 1795, 1881 and 1963 had some very low average values for consecutive days in late January also. I think the bottom line is that this cold spell on some guidance is approaching those limits and the absolute limit must be the -12 C that was the coldest daily mean on record in Jan 1838. That was on the 20th. 

Wow. That's some statement Roger if you think some of the records could be  equalled. A mean of minus 12 would have to see max temps of around minus 10c!

You must think the models must have underestimated the depth of cold coming so far. Does seem that way if you look how much colder the ensembles are trending now. 

This forum might be going into bedlam soon! 

[Roger J Smith]

I don't think that -12 is in a lot of danger but some of the daily records around 3-5 February are weak ones (low hanging fruit so to speak) and if cold intensifies around then, one of those could fall. These more robust records are near the outer edge but last March we did nip one from 1785 (1st of March, -3.8) and weeks ending 2-4 March 2018 rank second coldest. But I'm basically just responding to your conversation about what the absolute coldest periods were at this time of year. Anything seems possible given the range of model output we've been seeing, but with the warmer oceans, it's difficult to get within 1 or even 2 degrees of old records, you can have the same atmosphere but it does pick up that extra bit of warmth (and then dumps it as extra bits of snow, perhaps). That was certainly the case in Wexford and Wicklow last year (70 cm of snow reported in places).

Edited January 16, 2019 by Roger J Smith

[Connor Bailey Degnan]

Icon, awful start to the day :/.

[Cheshire Freeze]

People shouldn't be shocked by the ICON, this is a 50/50 evolution. 

As I've said, I wouldn't be surprised if we bypass the Greenland heights phase and go Scandi heights very late Jan/early Feb

[The Eagle]

UKMO not following the ECM unfortunately. Takes LP with the jet straight through the GIN corridor. Not enough of an angle for a diving low.

[Cheshire Freeze]

2 minutes ago, The Eagle said:

UKMO not following the ECM unfortunately. Takes LP with the jet straight through the GIN corridor. Not enough of an angle for a diving low.

Yes, too fast with that low exiting the ESB to allow an EC progression post day 6

Edited January 16, 2019 by CreweCold

[The Eagle]

GFS same, nite.

[Cheshire Freeze]

5 minutes ago, The Eagle said:

GFS same, nite.

GEM looks decent though...lol

EC has the mighty GEM by its side. Lord help us.

[mountain shadow]

Theme of the Winter model output...

The 12z giveth and the 0z taketh away.

[Cheshire Freeze]

1 hour ago, CreweCold said:

As I've said, I wouldn't be surprised if we bypass the Greenland heights phase and go Scandi heights very late Jan/early Feb

Maybe sniffing around my expectation for very end of Jan? 

Edited January 16, 2019 by CreweCold

[feb1991blizzard]

GEFS even worse than the 18z - less amplification.

[Mucka]

Not much support for ECM except just maybe UKMO would have some disruption and a handful of GFS ensemble members still go with good trough disruption around day 7/8 but many are flatter.

GEM, GFS and ICON are all pretty poor tbh.

Still plenty of drama to come I guess.

 

Edited January 16, 2019 by Mucka

[SLEETY]

Least it's the models with the worst verification stats and lowest resolutions that are poor, waiting for ecm to restore the balance, hopefully

Edited January 16, 2019 by SLEETY

[Cheshire Freeze]

5 minutes ago, Mucka said:

Not much support for ECM except just maybe UKMO would have some disruption and a handful of GFS ensemble members still go with good trough disruption around day 7/8 but many are flatter.

GEM, GFS and ICON are all pretty poor tbh.

Still plenty of drama to come I guess.

 

Ensemble mean at odds with EC46, that's for sure

[knocker]

Moving briefly forward from the short range with the gfs. The trough east of Greenland will track east and the associated fronts will briefly suppress the ridge as they track south east across the country on Tuesday bringing some rain sleet and snow along with some strong winds After this the high again surges but it's a continuing battle with the energy exiting the eastern seaboard.