[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Hirlam, Arpege and GFS 06z in good agreement on this: 5-10cms widely. More with elevation.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

31 minutes ago, Severe Siberian icy blast said:

The BBC said 20cm or more on hills later today. You think it's posible?

Entirely possible Shaun

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Quite good model agreement now for a further 5-10cms later today, Hirlam and Arpege as well as gfs and EC stalling the front over us giving slightly deeper returns. I would once again favour Hirlam here. Snow on snow, such a rarity. Plus, wind speeds still enough to create blowing and drifting for the next 12 hours.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Hirlam keeps the interest going into the early hours for the south west and west of the region. This and Arpege give 5-10cms from tomorrow's band.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

3 minutes ago, snowqueen1979 said:

We are now an Amber for the rest of today and tomorrow!  

And confirms something we were seeing from this morning - this storm was much further east than the modelling was suggesting, Hirlam and Arpege apart (although the latter went tonto late on)

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

EC rolling out also seems to have initialised poorly with the eastward extent of the storm. Models not very good on this one.

The sweet spot looks to be Salisbury Plain.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Yesterday's Euro4 and Arome have already bust with their projected snow amounts for here. And we have another 5-7 hrs to go.....

... plus something to chase tomorrow...

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

That eastward extension of the heavier ppn towards Brighton is really impressive, and bodes well for later on this evening. 

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

That band of ppn over Hampshire and Wiltshire is definitely consolidating and intensifying. Most of it looks destined for areas west of Worcester, but there is a definite eastern extent which should hit west Warwickshire and east Worcestershire.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Right now I don't think any model has handled this systems' northward track and speed well at all. GFS now probably best representation, but even that looks slow.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Moderate snow with high winds here. Nice little development east of Jersey and pleasing north-east thrust to the system in the Channel right now. Also watching that ppn around Southampton.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Moderate snow continuing here, and likely to get a bit heavier in the next hour. Exactly as Hirlam and Arpege were suggesting yesterday.

Real deal is currently showing over Brest and forecast to track north - that's what you need to keep an eye on later this afternoon. At present, everything seems a few hours ahead of most modelling. Unbelievably Met Office still has me down as dry !!

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Light to moderate snow here. Looking at the radar returns, no model has captured this movement this far north. Hirlam probably the closest. Going to be an interesting afternoon watching the radar.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

1 minute ago, snowhope said:

@Glacier Point What are you thinking for Worcestershire (i am in Upton upon Severn, fairly near you I think) over the next few days GP? Looking at the Met and BBC latest forecasts we seem to be on the Eastern Edge of the precipitation with the heavy stuff missing us and going into wales and staying in the South West. Where would you anticipate to get hit the heaviest?

I'm looking forward to driving up to Bredon  (if I can) on Friday, but on the basis of what I'm seeing so far, I would go 8-10cms for our lowland locations, 10-20cms for more elevated. I was struck how well Hirlam, Arpege and EC performed during December's snow events. These three models would form the basis of current thinking for Thursday into Saturday.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Arome further west with its accumulations..

Still in the ball park, but west would be best.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Hirlam and Arpege accumulations by t48:

Both in the 15-20 cms bracket for most on raw model.

Need to temper this against more underwhelming Icon and Arome. GFS in the middle and more tilted towards more accumulation during Friday / Saturday.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

GEM also consistent and more widespread in aerial coverage for Thursday into Friday.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

12z Arpege consistent with previous run:

GFS slightly better aswell. Definitely west and south-west orientation to this one as it stands.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

So, both hi res models over which whose territory this system is evolving - Hirlam and Arpege (both I would have a lot of respect for) - have very decent accumulations forecast by Friday morning from initial front:

Not so different from GEM, EC op and Euro4 in aerial extent.

Thursday also peak winds so the two combined offer the potential for a genuine, bona fide blizzard, at least for western and south-western parts of the region.

Still a lot of uncertainty on eastward extent of the initial front's progress, and intensity varies greatly, as does the question of extent and intensity of the frontal band on Friday / Saturday. Could it really be ? Blizzard followed by another fall ?

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Ec is around 10cms. Take hirlam, ec and arpege as the best guidance

[Model output discussion - the beast arrives]

11 minutes ago, nick sussex said:

I see GP is in the house.

I know he can’t say too much because of his job but a question if I may.

Looking at the MJO this has recently gone through phase 8 and into 1 .

Given the time lag is it possible there’s a bit of a conflict between the recent warming as in where it wants to put blocking .

And what the trop effect should be given the MJO.

 

 

Nope - I would be concentrating on the GWO, low amplitude La Nina type pattern. Broadly suggestive of the blocked type pattern in the NE Atlantic. 

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Both Hirlam and Arpege suggesting some potential snowfall during Thursday in advance of the main front programmed Friday. GFS making less of this at the moment, GEM, continues in its crazy snowfest.

Both models also suggest as some organised shower activity tomorrow afternoon.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Going to be a useful set of 12z data coming in. Most here would be wanting GEM to continue on its 00z - gave upwards of 15cm widely across the Midlands by Saturday. 

I would be giving most value to Hirlam and Arpege in this scenario where the low is coming up from the south.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

Just need a 30-40 mile jog with the majority of models forecast for Thursday to the east and upping the intensity and I will be happy.

[The Midlands Regional Weather Discussion 19/01/2018 Onwards]

moderate / heavy shower here, eyeing up that shower east of Leicester.