scotland Scotland Regional Discussion 10/03/13 09z ------>

[Buriedundersnow]

This is a little thing i decided to start on Thursday to have a little look at how the new NASA HIGH RESOLUTION LONGER RANGE model performed through this easterly at its longer range as we can all see verification numbers but this will be a better look at its positioning of low pressures and high pressures

I started Thursday taking starting points from 72h, 96h and 120h and using the 0z and 12z runs i brought all three starting points in at 12 hour intervals to see how accurately this model has performed

I also took the same parameters and done the same with regards to the 850 temps as well

I haven’t bothered with 24h or 48h starting point as lets face it a high resolution model should be fairly good within that range

The 12h charts at the end of the 5 day run are missing cos i couldn’t be bothered waiting another 12 hours for 2 charts as then i wouldn’t be posting this till tomorrow and i thought once it gets down to 24 surely it cant change that much

Now i have my own thoughts on how this model has performed but i will leave u to decide what you think of its performance and see if we can come up with some broad consensus between everyone on how this model has done lately and if it is a worthwhile tool for us to use in the future as a longer range high resolution model

For newer members who maybe don’t know once u have clicked on the first image to enlarge it u can use the right arrow key to flick through the images

ANOTHER POST WILL FOLLOW THIS ONE.

72h

72h 850

96h

96h 850

120h

120h 850

Edited March 11, 2013 by Buriedundersnow

[101_North]

Just phoned home to check everyone was back from nursery OK - roads still bad. This mornings showers has added about another 2-2.5 inches for a total of around 5 inches out the back garden. Quite impressive.

[Buriedundersnow]

now in this post i am just going to take the carts from the start and the end of each run so i will take the 72h, 96h and 120h starting point charts and pair them with the end chart on each run to have a look at how close at the end it was to the chart at the start of its run and what differences there might be

again there isnt a 12h chart on the 120h run as i didnt want to wait but there wont be too much difference from that chart and the 24h chart i am showing

72h

72h 850

96h

96h 850

120h

120h 850

[JoeShmoe]

think thats it for the day/spell, been a geat 18 hours though, snow melting rapidly in the sun

[LomondSnowstorm]

think thats it for the day/spell, been a geat 18 hours though, snow melting rapidly in the sun

Oddly it's back down to -1C at the airport so we're seeing some snow melt with sub zero air temperatures. Isn't too bad here and I think the higher bits of town should hold onto the vast majority of their cover in the next hour or two where melting is likely to occur.

[NUT]

Can't see any more showers here now with the wind due to turn northerly soon. Can see the clouds to the east and at times it does look they want to blow in and hit us but they blowing away from us each time they come closer

[Sunny Leith]

Heehee...I'll leave the physics to LS but with the increasing angle of incidence of the sun in mid-March I guess no surprise. But even in Edinburgh I've seen snow remnants lying about for 2-3 days in the early days of April in the shaded/wooded areas of parks. If air and ground temps are cold enough, it isn't too windy and theres nae rain, then it can hang about under shelter. Think there'll be plenty of visible evidence of todays snow in the next day or two here...

Anyway, snowing again !

Oddly it's back down to -1C at the airport so we're seeing some snow melt with sub zero air temperatures. Isn't too bad here and I think the higher bits of town should hold onto the vast majority of their cover in the next hour or two where melting is likely to occur.

[NorthernRab]

think thats it for the day/spell, been a geat 18 hours though, snow melting rapidly in the sun

Fingers crossed you get some large icicles forming as the sun gradually sets.

[LomondSnowstorm]

Heehee...I'll leave the physics to LS but with the increasing angle of incidence of the sun in mid-March I guess no surprise. But even in Edinburgh I've seen snow remnants lying about for 2-3 days in the early days of April in the shaded/wooded areas of parks. If air and ground temps are cold enough, it isn't too windy and theres nae rain, then it can hang about under shelter. Think there'll be plenty of visible evidence of todays snow in the next day or two here...

Anyway, snowing again !

Yes, direct sunlight tends to do the trick after about mid-February even, ironically we spend all winter looking for clear spells and now we get it the sun's too strong!

[Norrance]

Managed a few flurries and one decent shower here today. Sun has been to work on South facing roofs but most ground cover intact. Temp crept a notch above zero so no March ice day here.

It will be at Glenogle though. Last report at 1400 was -6C from a max an hour earlier of -5.7C so far today.

[NorthernRab]

Yes, direct sunlight tends to do the trick after about mid-February even, ironically we spend all winter looking for clear spells and now we get it the sun's too strong!

It's easy to forget that by mid-March, it's not far from 3 months since the longest day i.e. there are 4 hours more daylight every 24 hours, and the rest of the daylight comes with a considerably stronger sun!

Edit: Bit of a Scrooge topic given the amazing weather today, but interesting nonetheless!

Edited March 11, 2013 by NorthernRab

[Sunny Leith]

Aye, and on the other side of the coin, I can recall a few days in the December parts of 09/10 and 10/11 spells, where the sun came out after a cloudy-ish start and then the temperature went down straight away. Suggests that mid-winter sun in these parts - sometimes when we're in real deep cold - isn't always strong enough to overcome daytime situations when the sky opens up and allows further heat transfer from the surface.

Or something like that.

I'm bluffing now.

I only did physics to O level fer goodness sake !

Yes, direct sunlight tends to do the trick after about mid-February even, ironically we spend all winter looking for clear spells and now we get it the sun's too strong!

[Ravelin]

Sun's been working here in Dyce too with the thin coverings on roads, paths, carpark etc largely having disappeared. The covering on other areas such as grass is still there though. I'll see how much remains when I get home to Kemnay where the covering was deeper to start with. I suspect it'll be a similar story though since we've had wall to wall sunshine all day so far. Just a pity I'm sat in work, and with the blinds half closed too as it's just too bright now the suns moved around to this side of the building.

[Sunny Leith]

Realistically most of us know that March snow doesn't hang about too long on exposed surfaces. At this time of year I tend to focus more on the nature of any cold events rather than have any expectation of snow lying about for days on end. The last 24-36 hours have been such an event, and hopefully we can get a few more noteworthy days of cold or snow.

On the other hand I recall in the office I used to work in, watching another research group sitting about outside in last years 70F March warmth...and I'm just as happy if we get days like that. Doesn't seem like thats on the cards this year though...

[LomondSnowstorm]

Aye, and on the other side of the coin, I can recall a few days in the December parts of 09/10 and 10/11 spells, where the sun came out after a cloudy-ish start and then the temperature went down straight away. Suggests that mid-winter sun in these parts - sometimes when we're in real deep cold - isn't always strong enough to overcome daytime situations when the sky opens up and allows further heat transfer from the surface.

Or something like that.

I'm bluffing now.

I only did physics to O level fer goodness sake !

I think that's about the gist of it, late November-late January, radiative heating from cloud cover>solar insolation, mid February-early November solar insolation>radiative heating. Also in winter in easterlies SSTs>> upper air temperatures and SSTs>typical 'ideal' land temperatures, hence the increased convection and increased marginality effect.

[Northernlights]

Just checking my local forecast onhere to see if we need to take anymore frost precautions tonight and I notice we are down for a min of -1c .at 9.00pm .I will check then but feel you could almost add a zero to that as its freezing already.

[Penicuikblizzard]

Well back in Penicuik now, 5 inches level snow on my outside table, drifts almost 2 feet up my back door impressive for march, looks like the north sea snow machine has lost the energy for east Scotland!! Still plenty showers NE Eng south!!

[Sunny Leith]

Well the day's not done here (and the temperarature could still go up) but looks like Edinburgh Airport has indeed just missed out on an ice day. But thats been one heck of a cold March 24 hours however you look at it... don't think we'll say stats like that again in the Embra area until we get into a decent cold spell sometime next winter.

[JoeShmoe]

Think that might be it now for low lying Embra BT....marginal uppers going forward it looks like

[101_North]

Well the day's not done here (and the temperarature could still go up) but looks like Edinburgh Airport has indeed just missed out on an ice day. But thats been one heck of a cold March 24 hours however you look at it... don't think we'll say stats like that again in the Embra area until we get into a decent cold spell sometime next winter.

Shame an official ice day missed by a 1 degree blip at 3pm!

[Sunny Leith]

Shame an official ice day missed by a 1 degree blip at 3pm!

Think that might be it now for low lying Embra BT....marginal uppers going forward it looks like

Yeah I think thats probably the last winter-day of this type that we'll see this side of next winter. Could be a few surprises yet before spring is out but today was a high-quality snowfall day. Leaves me satisfied overall for the 2012/2013 autumn/winter/spring period, after a few months of thinking that easterlies were cursed again in these parts - but they weren't !

Looks like the convection is eventually dying away now on the radar (although I've seen sporadic very light snow every now and again over the last 2 hours). With clearing skies its going to be a potentially punishing frost.

Edited March 11, 2013 by by-tor

[NUT]

-2 here already apparently..................I'm not convinced though

[snowy owl]

Well feeling really raw in the wind out. Icicles formed everywhere, only thing not frozen is my chickens water?!

[Buriedundersnow]

12z UKMO at 144h looks to have the atlantic blocked but a few changes and it could look really good for us

i have done a little paint in the two northern hemisphere look.

first pic inside the red outline is the area in this chart which is really ruining the chances of the cold air returning from scandinavia

this second pic i have put a red line which is closer to where we want to see the 1025 or 1020 line positioned then the yellow arrows show where the flow would come from out of scandanavia and this setup would give us a near repeat of what we have just seen

[scottishandy]

Always been a wee bit suspicious of my RH reading on my weather station, but dewpoint is currently reading -13 which is quite impressive at 0.3 air temp. Dry air!