Model Output Discussion - A cold start to Spring?

[Updated_Weather]

Well well well.

I did say there will be south adjustments, and if we are pushing it. I think even more south adjustments may occur.
Also, *maybe* models are also underestimating precipitation. Happened last night for example. Models had barely anything and reality was.. It was a much bigger and more precipitation than it thought.

I think things have just got more interesting.. Will be interesting to see ECM control once it's out! On to the 18z!!

[Ali1977]

This is mental, Friday the heavy snow is way back south!! I’m thinking I could get a foot here

[Stuie]

1 minute ago, bluearmy said:

The dp’s are generally fairly borderline where the main precip occurs so I wouldn’t be certain that we won’t see more of a slush fest than a winter wonderland away from >400 feet.

its very tricky  

Very true Blue. I am currently -5 DP and does raise when systems come in. Also dependent on the wet bulb level and 850`s. Tricky yep.

[Snowyowl9]

If that wasn t enough the UKMO shows another low which could slide further south and much colder Nly coming in after..

[Guest]

Just how much have the synoptic charts changed for Friday?

Tonight's 12z ECMWF: 

T+120 chart from two days ago:

The T+168 chart from four days ago:

That is a great example of the cold hanging on longer than modelled even as the Iberian ridge builds.

Edited March 7, 2023 by Guest

[Mcconnor8]

I think looking at the Radar the system moving in tonight from the SW is more North than modelled so potentially could impact further into the UK.

[sheikhy]

For me its radar watch and sat24 from here!!!temps down to 1 degree already!!plummeting!!current dew point -6!

Edited March 7, 2023 by sheikhy

[IanT]

13 minutes ago, bluearmy said:

The dp’s are generally fairly borderline where the main precip occurs so I wouldn’t be certain that we won’t see more of a slush fest than a winter wonderland away from >400 feet.

its very tricky  

Very very tricky…

It goes without saying that higher is better, but it’s easy to see how this could result in quite a widespread fall also. MetO is right to put the warnings out. Dew points will be the key and they can generate and sustain their own change in precipitation. And the heaviest snow falls we see in this country tend to happen when temps are above freezing….

Edited March 7, 2023 by IanT
Missed a bit….

[Ali1977]

I imagine i’ll now not sleep till Friday night if these charts materialise - I’ve never looked forward to a pub run this much for ages!! 
 

Edited March 7, 2023 by Blessed Weather
Ref to MetO warnings/forecast removed.

[Mark wheeler]

3 minutes ago, mountain shadow said:

BBC still embarrassingly showing the snow way North.

Is it still showing snow and 10c too ?

 

Latest Arome has a wintry mix further south.

Edited March 7, 2023 by Mark wheeler

[Lampostwatcher]

36 minutes ago, Tim Bland said:

ECM looking good for for the south up to midlands tomorrow…

Bank bank bank 

[MATTWOLVES 3]

Absolutely no bias from me regarding this Snow..some are gonna hit the jackpot and others are gonna miss out due to location and height! Now that would be a shame. I'm thinking Midland areas could be close to hitting a   That's not to say it won't all change again come the later runs! It's gonna be very interesting as to the met changing these warnings before tomorrow Lunchtime..I've a sneaky feeling later this evening we could see a change!

We are now at the stage of what will be will be.

I'm gonna wish all the best of luck for falling and settling snow.

Seriously though its pretty cool to even be in this position in March after a largely poor Winter..and just goes to show how PV damage puts us in the game.

So this time tomorrow some of you may be saying....what Blizzard...its just a couple of flakes..while others like Ali and Shaky probably running down a country lane naked..watch those extremities lads

[markw2680]

4 minutes ago, Ali1977 said:

I imagine i’ll now not sleep till Friday night if these charts materialise - I’ve never looked forward to a pub run this much for ages!! 
 

Where’s these Amber warnings, surely this is now deserving of one

Thinking I might join you with a spot of lamppost watching. Think the models will still bring Thursdays a bit further south yet personally 

[bluearmy]

5 minutes ago, Ali1977 said:

I imagine i’ll now not sleep till Friday night if these charts materialise - I’ve never looked forward to a pub run this much for ages!! 
 

Where’s these Amber warnings, surely this is now deserving of one

On the back of a single ec run ?  No chance unless their short range higher res runs back that up 

Edited March 7, 2023 by bluearmy

[Stuie]

6 minutes ago, MATTWOLVES 3 said:

Absolutely no bias from me regarding this Snow..some are gonna hit the jackpot and others are gonna miss out due to location and height! Now that would be a shame. I'm thinking Midland areas could be close to hitting a   That's not to say it won't all change again come the later runs! It's gonna be very interesting as to the met changing these warnings before tomorrow Lunchtime..I've a sneaky feeling later this evening we could see a change!

We are now at the stage of what will be will be.

I'm gonna wish all the best of luck for falling and settling snow.

Seriously though its pretty cool to even be in this position in March after a largely poor Winter..and just goes to show how PV damage puts us in the game.

So this time tomorrow some of you may be saying....what Blizzard...its just a couple of flakes..while others like Ali and Shaky probably running down a country lane naked..watch those extremities lads

No bias either Matt, only post what the models are showing. I still think FI is 24hrs at the min so as much as Thurs/Fri are modifying the LP track, who knows. 1 thing I have seen from today is the ECM is following the UKMO. Tomorrow? who knows. At least it isn`t drab mate. Take it easy.

Edit: I am supposed to be going to Lincolnshire Friday to a 2nd hand record store so maybe a bias to switch things up.

Edited March 7, 2023 by Stuie

[chris55]

42 minutes ago, Tim Bland said:

ECM looking good for for the south up to midlands tomorrow…

No apologies IMBYism, but tonight’s EC is one of the best short term snow forecasts I have seen for my area in many years! 

[Ali1977]

3 minutes ago, bluearmy said:

On the back of a single ec run ?  No chance unless their short range higher res runs back that up 

Arpege, arome, ECM , GFS are all showing over 10 cm in a decent area, mainly falling over rush hours - that’s not just a yellow warning I wouldn’t have thought. Although, I’m not sure how they decide - they obviously have other better models too I guess!! 

1 minute ago, steveinsussex said:

How on earth can an Amber warning be issued when they really have no idea where the snow will track…

Because over 1 inch in rush hours causes serious issues - seems pretty simple and a risk factor that’s worth an Amber warning  

[Nick123]

Ecm and ukmo looks good for the South but don't count ur chickens before they hatch. Interesting how UKMO went against the raw data. This ain't over yet

Edited March 7, 2023 by Blessed Weather
North/south bias comment removed.

[GokouD]

21 minutes ago, Ali1977 said:

This is mental, Friday the heavy snow is way back south!! I’m thinking I could get a foot here

Man, if this run comes off it could rival December 2017 IMBY, which is the heaviest snow I've seen while living here.

 

[Updated_Weather]

9 minutes ago, Nick123 said:

Ecm and ukmo looks good for the South but don't count ur chickens before they hatch. Interesting how UKMO went against the raw data. This ain't over yet

If anything. Expect further south adjustments, potentially ruling out the north!

Edited March 7, 2023 by Blessed Weather
North/south bias comment in quote removed.

[DAVE_ALLEN]

22 minutes ago, Updated_Weather said:

Well well well.

I did say there will be south adjustments, and if we are pushing it. I think even more south adjustments may occur.
Also, *maybe* models are also underestimating precipitation. Happened last night for example. Models had barely anything and reality was.. It was a much bigger and more precipitation than it thought.

I think things have just got more interesting.. Will be interesting to see ECM control once it's out! On to the 18z!!

Well snow is falling already in Sw Ireland from the incoming Atlantic warm front. And it that’s possible there. A further shift south could well bring snow along the south coast. 

[sheikhy]

23 minutes ago, I remember Atlantic 252 said:

I feel we may be too far north, dumping areas seem to be B'ham southwards for all 3 systems, Wed to Fri

Yes buddy defo!!kinda reminds me of december 10th 2017 and the one in january 2021 but just 3 months later!!same angle of attack!it could still shift even further south!!!

[goosey007]

13 minutes ago, Updated_Weather said:

They would be still using out or date data no?

yes from this mornings ecm run ......10c and showing snow is plain nuts!

[sunnijim]

It does make me wonder if the second ( although some say it was part of the original)  SSW is having effect now on the modeling toward the end of the week.

We hear alot about warmings taking 2 weeks or more to show their hand, if it was all part of the original warming could it negate that time frame? especially if the pattern is already in place from the first reversal.

Just giving it that extra kick when we needed it most.

Edited March 7, 2023 by sunnijim

[Whether Idle]

Southwards is the trend as the models catch up. Has the southwards correction reached its maximum extent or will the lows tack into the channel? Fascinating stuff.