johnholmes

Well some 3 days since I posted the NOAA and ECMWF latest charts, the 6-10 day issue takes us into the Christmas period. I wonder if they suggest a cold one? NOAA 6-10 out to 23 December and it is showing a very strong westerly into the UK. This from a fairly marked trough off the west coast of north America, into a slight ridging east of this with the westerly over the rest of the chart into the UK. Heights around the Border region are on the lowish side at about 540 DM; (I might be 6DM out as the gradient is so strong making it hard to decipher the actual height). It also suggests, with a large temperature gradient in the east of n America, that there is a good chance of it being a windy and unsettled period in much of the UK. With fairly low heights then wintry type ppn from about the Peak District north on high ground and low ground in the more northern parts of Scotland would be probable. At this distance suggesting anything more detailed is a waste of time. The 8-14 shows 534 DM in the Border area so remaining on the cold side of normal and further disturbed weather likely. That is assuming these two charts are on the correct lines! Turning to ECMWF, period 20-24 December, and it shows a 500 mb trough just east of the UK, extending SE with a strengthening north of west flow which has backed slightly and also decreased a bit in strength by Xmas Eve. The 850 values are around zero C for much of the country most of the time; the colder air -5C is predicted to be largely well into Europe even in the centre of the extended trough. Both sets of chart do suggest colder than rather than above normal temperatures. So I’ll be watching how they both develop over the next 3-7 days! Looking just above my post I see Mike is in about the same place as me! Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4976321

Well some 3 days since I posted the NOAA and ECMWF latest charts, the 6-10 day issue takes us into the Christmas period. I wonder if they suggest a cold one? NOAA 6-10 out to 23 December and it is showing a very strong westerly into the UK. This from a fairly marked trough off the west coast of north America, into a slight ridging east of this with the westerly over the rest of the chart into the UK. Heights around the Border region are on the lowish side at about 540 DM; (I might be 6DM out as the gradient is so strong making it hard to decipher the actual height). It also suggests, with a large temperature gradient in the east of n America, that there is a good chance of it being a windy and unsettled period in much of the UK. With fairly low heights then wintry type ppn from about the Peak District north on high ground and low ground in the more northern parts of Scotland would be probable. At this distance suggesting anything more detailed is a waste of time. The 8-14 shows 534 DM in the Border area so remaining on the cold side of normal and further disturbed weather likely. That is assuming these two charts are on the correct lines! Turning to ECMWF, period 20-24 December, and it shows a 500 mb trough just east of the UK, extending SE with a strengthening north of west flow which has backed slightly and also decreased a bit in strength by Xmas Eve. The 850 values are around zero C for much of the country most of the time; the colder air -5C is predicted to be largely well into Europe even in the centre of the extended trough. Both sets of chart do suggest colder than rather than above normal temperatures. So I’ll be watching how they both develop over the next 3-7 days! Looking just above my post I see Mike is in about the same place as me! Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

A ground frost early on with a low of 0.1 C then slight rain with 0.6 mm since midnight, dry now with temperature up to 3.0 C

Overcast, dry after slight rain in the early hours; 0.4 mm since midnight, temp is still drifting dow, low currently at 6.2 C

Dry now after overnight rain=3.8 mm since midnight; a low of 5.4 C

No signal for any 'deep' cold on either NOAA or ECMWF, NOAA 6-10 and 8-14. Of course they might be wrong but in 12 years or so using them it is fairly unusual, especially with the 6-10. Anyway I'll post them below for anyone who wants to have a look themselves. A big thank you from me to snowking also Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

Dry and mostly cloudy as far as I can see, 0.2 mm since midnight and a low of 6.8 C

Starting with rain (radar suggests several hours more; a low of 5.7 C

Mostly clear skies, dry and a low of 5.2 C

1509 and almost dark with rain at times, temperature has struggled up to 5.8 C-wonderful!

Lovely to get the coldie message across in such a light hearted

many thanks Daniel, how do I do that for other charts that get posted please; sorry to be a pain

Is it possible to slow it down please then my old eyes might be able to follow what is happening along with the time scale thanks for any help

Mine was similar timing. This will be a feature of any frosty mornings until about the end of the 1st week of January when we have full radiation nights and the late sunrise.

Looking at the ECMWF output from 12-16 th December=upper trough giving way to upper ridge with surface high near by to SW. So generally dry, rather cold becoming less cold, rather above normal for most of the country?

Clear blue start with another white frost and a low of -2.7; the 4th air frost this month

Looking at the NOAA 6-14 day charts and no signal at all for a change to a general westerly upper flow, similar on the ECMWF, time scale on that similar to the NOAA 6-10. Little showing way out west to suggest any change just yet Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4970389

Looking at the NOAA 6-14 day charts and no signal at all for a change to a general westerly upper flow, similar on the ECMWF, time scale on that similar to the NOAA 6-10. Little showing way out west to suggest any change just yet Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

Dry at the moment but a fairly wet night (4.4 mm) following a wet cold day yesterday 11.8 mm and a max of 5.2 C, so far the min overnight shows 5.1 C

Wow what a huge task this is, it seems to get larger each year as the knowledge increases. Fantastic Job Nick-thank you. It seems a long time since you first arrived and we used GFS 4x outputs to try and do a daily forecast!

Raining again, 7.2 mm since midnight but some might be melted snow from 24 hours ago, from a low of 1.4 C at midnight it has risen to 4.3 C and still edging up

This at the Lauberhorn start area, think there are 4 or 5 lifts open this weekend https://www.jungfrau.ch/webcams/lauberhorn/#/

35 cm 30 Nov-1 Dec 2010, did a summary of this with photos, can try and find it if wanted

About 2 to 2.5 cm snow here, already slight thaw T=0.7

Dry now and overcast after snow earlier, maybe just about 1 cm, a low of -0.6 C now up to 0.4 C