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Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire
Posted
1 minute ago, WYorksWeather said:

I'm not sure about the lack of extreme temperatures at the surface. Those ECM 850hPa anomalies are pretty extreme for the time of year, widespread +10C:

image.thumb.png.e6bd0d459cf12f2b33b21ff2ef022de2.png

It's enough for temperatures like this on the last four frames from T+222 to T+240:

image.thumb.png.06272f324bab2c924c27e715a61392c1.png image.thumb.png.904eff9ec8b8bca2b7e0c7f526b5be18.png image.thumb.png.b4deb358745364f4e4f0b3edf0e4f6a5.png image.thumb.png.9b40fffbf66106dbc7b61d1fe43f1ee1.png

Spot maxima in the high teens, meaning that in practice accounting for model bias you are looking at temperatures probably scraping into the 20s.

 

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But there's a dry, continental undercut...which at this time of year means lower dewpoints and cooler ground temperatures. If there was a TM source to the air then fair enough, but there isn't.

By mid October you can't just equate high 850s to high 2 metre temps.

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Posted
  • Location: Coventry, 96m asl
  • Weather Preferences: Snow Nov - Feb. Thunderstorms, 20-29°C and sun any time!
  • Location: Coventry, 96m asl
Posted (edited)
4 minutes ago, WYorksWeather said:

I'm not sure about the lack of extreme temperatures at the surface. Those ECM 850hPa anomalies are pretty extreme for the time of year, widespread +10C:

Spot maxima in the high teens, meaning that in practice accounting for model bias you are looking at temperatures probably scraping into the 20s.

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They are fairly warm, but mostly mid teens which is still not really close to date records, where that's all at 22C or above up to the 25th.

Edit: As Cheshire mentioned above, and was going to say myself, you also have inversions and undercuts with south easterlies this time of year.

Virtually all the date records set below, were very likely under southerlies - south westerly winds.

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Edited by Metwatch
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Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire
Posted

2mtemp_20231011_12_240.jpg

This shows it well. You can quite clearly see the undercut there despite the high 850s

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Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted

 

5 minutes ago, Metwatch said:

They are fairly warm, but mostly mid teens which is still not really close to date records, where that's all at 22C or above up to the 25th.

Edit: As Cheshire mentioned above, and was going to say myself, you also have inversions and undercuts with south easterlies this time of year.

Virtually all the date records set below, were very likely under southerlies - south westerly winds.

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One of the charts I posted though does have a spot 18C. I'd put money on the fact that given ECM usually underestimates, that's going to scrape 20-21C in practice.

Close enough I think to challenge date records, as a tiny shift could get us there. Agreed that date records are probably unlikely to fall with these charts as it stands.

I do wonder though what the latest +15C isotherm is. I remember reading that +18C earlier this month was a record breaker, so not sure what the highest is by late October. It would have to be close though.

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Posted
  • Location: Coventry, 96m asl
  • Weather Preferences: Snow Nov - Feb. Thunderstorms, 20-29°C and sun any time!
  • Location: Coventry, 96m asl
Posted (edited)
5 minutes ago, WYorksWeather said:

I do wonder though what the latest +15C isotherm is. I remember reading that +18C earlier this month was a record breaker, so not sure what the highest is by late October. It would have to be close though.

Probably this or 2014 Halloween

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Edited by Metwatch
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Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted
2 minutes ago, Metwatch said:

Probably this or 2014 Halloween

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2014 Halloween just about gets there if you squint at it - barely grazes the far SE coast by my reckoning.

image.thumb.png.58ac580f810b56b766521c738cb52194.png

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Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted
2 minutes ago, Cheshire Freeze said:

You won't get record breaking temperatures later in October with a wind that is east of south. Purely because the land cools much quicker than water. Long nights now mean that ground loses heat quickly overnight, dew points are low and the airmass just won't have the characteristics to support heat when it's of a continental source.

A southerly or SSW'ly that has some TM characteristics will hold more water vapour...this means dew points are higher and the airmass will be less affected by overnight cooling. 

This overnight airmass from reanalysis was enough for the date record the following day. You're right it is a bit more SSW based.

image.thumb.png.2662227d152af5b8d4127d42a5a2f416.png

However, I think that if we're getting raw output at 18C meaning a true maxima of likely 20-21C, it's not out of the question that a slight shift could give us some date record maxes.

Record minima are perhaps more likely though I would have thought.

In any case, probably better to start talking about record-breaking potential if indeed there is any a bit closer to the time - probably getting a bit carried away! The ECM was quite a bit higher than its mean towards the end, so probably the more likely outcome is mid teens, which is still pretty mild for late October.

image.thumb.png.fe843182cd6be547689fd9054bd2116b.png

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Posted
  • Location: Dorset
  • Weather Preferences: Warm and dry, or very cold. See my profile for model trivia
  • Location: Dorset
Posted (edited)

I do wish that this low pressure influence that has been favoured by the ECM would 'do one'...

image.thumb.png.28c8fbd1814f1beb2f4c3f0f3c835089.png

The latest ECM deterministic run wouldn't even have us wait until the Scandi high is in place for some unwanted LP interference!

image.thumb.png.21b7cda4b184cc2837467676a93408da.png

Partly for my own reassurance, here is the ECM deterministic alongside the three machine learning models, all showing their T+240h frames (by which point the Scandi high is in place), showing that the machine learning models don't seem to agree - for now - that I will be getting wet:

image.thumb.png.61262c2051cb4fb7b1f397489b32e7dc.png

The Google model (GraphCast) even seems to agree with the GFS about an easterly!

Edited by RainAllNight
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Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted

GFS has pretty much caved to ECM on the 18z. 12z vs 18z comparisons below.

At T+120 and T+114 there's not much change.

image.thumb.png.63e7bb53451699cd65c59161e1b78b73.png image.thumb.png.8db86bdb29df838cb892bdceb9cc8439.png

But at T+168 and T+162, the 12z as previously mentioned fires the mild air into the Atlantic, but the 18z scores a hit in similar fashion to the ECM 12z.

image.thumb.png.a967d20665df21215e50645da3417888.png image.thumb.png.ac4a984764984b3cbf9a07bd396d7e98.png

And at T+240 and T+234, the 12z is still cold, but the 18z is very mild and again, much closer to ECM than it is to the 12z GFS.

image.thumb.png.eac1c7a1b7b3bc8f840f69a4727f390e.png image.thumb.png.1d6804fad695d0a8086dda723d0469aa.png

 

 

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Posted
  • Location: Coventry, 96m asl
  • Weather Preferences: Snow Nov - Feb. Thunderstorms, 20-29°C and sun any time!
  • Location: Coventry, 96m asl
Posted (edited)
13 minutes ago, WYorksWeather said:

GFS has pretty much caved to ECM on the 18z. 12z vs 18z comparisons below.

At T+120 and T+114 there's not much change.

image.thumb.png.63e7bb53451699cd65c59161e1b78b73.png image.thumb.png.8db86bdb29df838cb892bdceb9cc8439.png

But at T+168 and T+162, the 12z as previously mentioned fires the mild air into the Atlantic, but the 18z scores a hit in similar fashion to the ECM 12z.

image.thumb.png.a967d20665df21215e50645da3417888.png image.thumb.png.ac4a984764984b3cbf9a07bd396d7e98.png

And at T+240 and T+234, the 12z is still cold, but the 18z is very mild and again, much closer to ECM than it is to the 12z GFS.

image.thumb.png.eac1c7a1b7b3bc8f840f69a4727f390e.png image.thumb.png.1d6804fad695d0a8086dda723d0469aa.png

 

 

Seems like the GFS joins the pack at least for tonight, with all main runs showing milder airmass arriving next week. Might be all different tomorrow again though, who knows.

However on the surface, temperatures would remain quite average, with low teens by day into central and southern areas.

One thing's for certain is that we're back to high pressure from this weekend until at least mid next week. Might be a boring spell for October, but at least it's not impactful in terms of flooding!

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Edited by Metwatch
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Posted
  • Location: Scouthead Oldham 295mASL
  • Location: Scouthead Oldham 295mASL
Posted (edited)

EC46 has some kind of scandy block

image.thumb.png.428eba7984728db5eb9feb3c799abd18.png

which migrates west week 2 

image.thumb.png.79e2bfdedaa09cb901f3695a881aab67.png

similar to UKMET LRF..

Edited by northwestsnow
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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
Posted

While it is theoretically possible to sustain a perverse outcome of mild southerlies, I don't see the model support for that to sustain as things stand. 

While subject to change, the two key things by day 9 on the GFS, GEM and Euro are..

1) They all shift the vortex away from the Atlantic as they ride our block north, eventually they'd dump into Russia. This basically reduces pressure on our block.

2) By day 9, they all have a second low by the Azores putting energy into the southern stream. So long as you don't have weird GFS style fizzle out then it's likely to either undercut or encourage the high to retrogress. Either outcome is good in our bid for surface cold and frosts. 

So long as the modelling does not change drastically then yes, it would suggest that the Euro weeklies were right for week 2.

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Posted
  • Location: Welwyn Garden City
  • Weather Preferences: Seasonal and interesting weather including summer storms and winter snow
  • Location: Welwyn Garden City
Posted

Yes spoit this morning with a scandi then Greenland high...

gfsnh-0-174.thumb.png.72126093a700ee511464d78dc57c23f1.png

gfsnh-0-378(2).thumb.png.bb6b19733167b2fc8c73b606b557c4af.png

..easterly cold pool as well !! 😆

gfsnh-0-234(3).thumb.png.d7afc9192cfbf8ba1f0f3d8aee044c20.png

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Posted
  • Location: Wilmslow, Cheshire
  • Location: Wilmslow, Cheshire
Posted
35 minutes ago, sheikhy said:

Seems to be back to cold this morning with a mammoth scandi high😍!

The ECM hasn't moved at all though. I know where my money is in a situation like this...

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Posted
  • Location: Leicester
  • Location: Leicester
Posted
19 minutes ago, Scorcher said:

The ECM hasn't moved at all though. I know where my money is in a situation like this...

Yup defo ecm always but i would like the gfs to be right on this occassion!!!!no more warmth im ready for frost and cold and eventually snow!!

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Posted
  • Location: Wilmslow, Cheshire
  • Location: Wilmslow, Cheshire
Posted
3 minutes ago, sheikhy said:

Yup defo ecm always but i would like the gfs to be right on this occassion!!!!no more warmth im ready for frost and cold and eventually snow!!

Your time will come for that but I don't think it's going to happen yet.

The odds are very much against the GFS scenario in FI. It keeps throwing up these op runs that are well below the mean.

 

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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill
Posted

According to the GEFS, the GFS ops in a smaller cluster, but low confidence in the GFS because of the apparent divergence:

image.thumb.png.e1d307b9afb3041ea2eaab516228dcc9.png 

One to watch to see where the models go...

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Posted
  • Location: Dorset
  • Weather Preferences: Warm and dry, or very cold. See my profile for model trivia
  • Location: Dorset
Posted (edited)

ECM's T+168h chart looks particularly unappealing compared to the others this morning...

image.thumb.png.180815fb0468a2cbcf1d6a268a3802df.png

It's better by T+240h, but the trough to our west/southwest still bothers me...

image.thumb.png.35e33174f9f00a7dccee0af67511a934.png

ECM for my south coast location...

image.thumb.png.09b2843bf3f607233e6c62b51fd07656.png

Edited by RainAllNight
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Posted
  • Location: Oxford
  • Location: Oxford
Posted

Good morning,ECM staying solid keeping a milder scenario in the medium term after a few colder days while GFS beginning to follow.Still GFS is continuing with the pressure rise to the north east not sure if that will occur in fantasy island but never say die.

 

Posted
  • Location: Evesham/ Tewkesbury
  • Weather Preferences: Enjoy the weather, you can't take it with you 😎
  • Location: Evesham/ Tewkesbury
Posted
40 minutes ago, Anthony Burden said:

Good morning,ECM staying solid keeping a milder scenario in the medium term after a few colder days while GFS beginning to follow.Still GFS is continuing with the pressure rise to the north east not sure if that will occur in fantasy island but never say die.

 

I've seen gfs and ecm falter time and time again over Scandi high development over the years. As I said before its the shape of that high which will allow  the UK either get cold or mild weather......I think it's 50/50 at the moment .....!☺😉

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