Eastbourneguy

Did somebody order some -AO descending down from the strat?

I'll just pretend this is the only output this morning.

Good evening everyone! Exciting model watching times ahead! One thing I would like to add when thinking about the 500 hPa Geopotential height, and forgive me if its already been discussed, but the height is taken from a reference level of 1000 hPa and not the surface. Adjustments to the actual thickness of the layer above the surface need to be made depending on the surface pressure pattern. This is an important to know when you're thinking about the general thickness/temperature of the layer, because if you're in a really low pressure pattern (quite often the case in the UK), the blues and purples can make it "look" like a colder/lower thickness than it really is in relation to the surface. Here's an example: Which area has a lower thickness? A quick glance and you might think over the UK, but on closer inspection the pressure over the northern circle is far higher. If we look at the area of 520 thickness and take away 20 hPa to account for the ~ 1020 hPa SLP, the actual thickness between the surface and 500 hPa is around 500 dm (a very cold thickness very rarely seen in the UK). Where as over the UK, adjusting the blue 510 area up by 20 gives you 530. Still a cold thickness, but a marginal one at the surface, as you usually want around 528 or lower for snow at sea level. This theory can be confirmed by looking at the 500 hPa and 850 hPa temp charts. The 500 hPa temp and height chart at the bottom is important here because even though the area over the UK has "lower heights", we know that's in reference to 1000 hPa and we can clearly see that the -35 C area at 500 hPa is far wider in our northern circle compared to over the UK. Happy model watching peeps

Finally some snow in Eastbourne! 98A82F8B-7751-484D-A0FB-15E2167D0669.mp4

Come on showers, come to papa (Leeds)

Still raining in poor old Eastbourne

Just plopping it down with rain in Eastbourne I'm told by my family, even though snowing in Seaford along the coast. 1.8C with 0.8 dew point, 3mm of rain an hour going to waste!

Come on ladies and gents The only significant cold spell I can remember that was modelled ‘relatively’ stress free for coldies was 2010, we should be used to this banter. However, I do find it hilarious that some were claiming the ICON to be be chosen one that foresaw this mighty downgrade, disregarding the GFS. Now they have flipped on 06zs(ICON colder, GFS warmer) and the same people claiming game over from a completely different model showing the ‘warmer’ solution. I do feel like when the ‘big 3’ all show cold but different synoptic evolutions, we need to stop convincing ourselves of model consensus which just isn’t true. Yes, extreme cold in the next 10 days seems less likely but game over?? See you at 3:30

Snowy back home! http://www.itsfine.org/weather/wx_webcam_quick.php Edit: Already eased off haha

First few flakes blowing around in Leeds

It begins - first showers starting to hit Aberdeen as well.

Just for some perspective, here is the +168 chart from 'That ECM', alongside our current +72 chart. Going to be an exceptional week guys and gals

The modelled snow depths by Friday on the 12z ecm below. Looks like Eastern Ireland is going to get walloped! For England and Wales, this run models all ppn falling as snow for the first 6 hours before ice pellets/freezing rain comes into the mix in the far south (roughly 40miles from the coast), snow further North. Then a return to all snow, even on the coast as the ppn begins to move northwards, up the spine of the country and even making it to Scotland.

Been analysing the ECM 12z ensembles, 40/50 of the members show the low producing an all snow event, even for the south coast - some runs the low doesn't actually make it towards the UK though. Of these 40 members, the 850s remain at least -1/-2 throughout, these members are still modelling precipitation as snow, presumably from low dew points coming from the frozen continent. Haven't looked at the longer term implications, but shows that at least in the ECM ensemble suite, most people still have a good chance of an all snow event from the low.

So 3-4 days of sub -10 850s (towards -15) for most. Convective showers and troughs forecast in that time and now the models trying to firm up on a low pathway that has potential to bring crazy amounts of snow somewhere. The ensembles are there for a reason, to pick out the average and have so far been very good with this spell, even with the occasional erratic behaviour from the ops on both the ecm and gfs. Yes, the gfs op recently could be correct with the low ruining the party in the far south but that’s not the ensemble consensus. Anyway, enjoy the next 5 days, may the streamers be with you.

https://weather.us/model-charts/euro/66-e-529-n/m1_temperature-850hpa/20180228-1800z.html Zoom to the UK, change the date to Wednesday mid-day, select 850hpa temperatures, scroll through the various 50 members and enjoy!

The GFS 6z ensembles show just how delightful this spell could be. The 'clean' runs with their mouth watering 850s vs the messy shortwave city runs, which still manage to maintain near enough -10 850s for around 4-5 days. I'm totally not excited.....

Can confirm 100% legit light snow in the Woodhouse area, Leeds.

LS2 here, just very, very light grains blowing around.

Picture of the rec around the corner from me. Same park as the photo from earlier. Edit: You should be able to see it now! http://postimg.org/image/a77s183kr/

The UKMO 850 temps there are definitely not correct there mate. +96 on the UKMO is actually reasonable for kent, sussex snow showers. (Not selfish at all honest =P)

So it's not even 2015 and the winter is over... There were only a few runs that actually showed some major snow opportunities for low levels for the next couple of days. To be honest only really the ECM mean had a strong signal for heights being further North East than what actually verified, not many op runs were actually that wonderful. A lot ofwasted potential yes but this wasn't a total model let down by any means. ECM, GEM, JMA, ALL show high pressure in the North of the Arctic around +200. So people spouting on about a raging PV setting up are frankly wrong. Both GFS runs actually show more of a centralized High in the Arctic but this is well into FI so just one to watch... We will have a few more bites at the cherry yet =)

Scene in Seaford an hour ago.

Winds howling here at the moment, I felt some ppn on my hand sticking it out the window. Can't actually see anything though as the lamp posts go off at 1am!

Sugary dusting on cars and walls here. Very light snow falling, dew point up to -2.