Jump to content
Holidays
Local
Radar
Snow?
Paul

Model output discussion - here comes the beast!

Paul

Please only post model discussion in this thread 

For more general chat and banter, or moans and ramps loosely around the models, please head to the banter thread:
https://www.netweather.tv/forum/topic/86721-model-moans-ramps-and-banter/

For general weather chat including about the snow/cold chances around the country, please go to the regional threads:
https://www.netweather.tv/forum/forum/142-regional-discussions/

We also have a special post SSW cold spell discussion open here:
https://www.netweather.tv/forum/topic/89358-ssw-related-cold-spell-will-it-wont-it/

Thank you!

Message added by Paul

Recommended Posts

96hours away people. Good start to the 18z runs from the Icon...

5A0FC0F6-F5D7-4991-8E38-279B720EEE7D.png

High further north, cold air pool further westward by about 6hrs. Marginally better wind angle. Decent improvements even by 108.

here is 120 on 12 (first chart) vs 18

BE892320-47B6-4140-8641-B5B4C4CEAEE2.png

F30485C1-4E60-4266-9A60-B893550DF201.png

Edited by ITSY

Share this post


Link to post
Share on other sites

yep IKON bang on the UKMO@120

maybe a smidge further North!!

A193872D-76E4-4923-AF30-84C0D4522518.thumb.png.c8ed6e0cbe59ddd2fcca05d5fab38a36.png

 

Share this post


Link to post
Share on other sites
17 minutes ago, Nick L said:

The EC is usually fairly keen to kill off shower activity as it trundles inland. Will be interesting to see the shower activity on the UKV and Euro4 over the coming days.

I would have thought that more strength in the sun as we approach early March may provide enough shallow heating above the ground to support some convective development inland as well - given how steep the lapse rates will be, something the models may not simulate well - through experience of seeing no ppn shown inland by a model but showers still popping up.

 

Edited by Nick F

Share this post


Link to post
Share on other sites
2 minutes ago, ITSY said:

96hours away people. Good start to the 18z runs from the Icon...

5A0FC0F6-F5D7-4991-8E38-279B720EEE7D.png

High further north, cold air pool further westward by about 6hrs. Marginally better wind angle. Decent improvements even by 108.

Yes 12z on left 18z on right :good:

iconnh-0-120.thumb.png.4486aa51c2ff278b416a17da6945d517.pngiconnh-0-114.thumb.png.f3d96ebefa66ff6bf3a25b09446d1406.png

Share this post


Link to post
Share on other sites

ICON has cold uppers ploughing into the uk on Sunday, earlier than its 12z run

90D77BDF-E9A6-4C0E-ACA6-82BB47319408.thumb.png.27ed0714b736f57a9dd375652a622c50.png04B0BA4D-94DC-48BC-99B4-550B41CC1EDA.thumb.png.0b3c5313c7809193902c78ddce8e1cea.png

Share this post


Link to post
Share on other sites
3 minutes ago, Nick F said:

I would have thought that more strength in the sun as we approach early March may provide enough shallow heating above the ground to support some convective development inland as well - given how steep the lapse rates will be, something the models may not simulate well - through experience of seeing no ppn shown inland by a model but showers still popping up.

 

I  thought the lack of moisture would negate the laspe rates , surface thermals ? 

Edited by rory o gorman

Share this post


Link to post
Share on other sites
1 hour ago, Nick L said:

I'll add to this, it will all depend on what the ratio of liquid water to snow ratio these maps are using too. Dry snow will put down about 3 times more than wet snow for the same equivalent of water.

question for you @Nick L 

is there any type of chart/graph that i can look at that will show this or is it a case of now casting

Share this post


Link to post
Share on other sites
3 minutes ago, Nick F said:

I would have thought that more strength in the sun as we approach early March may provide enough shallow heating above the ground to support some convective development inland as well - given how steep the lapse rates will be, something the models may not simulate well - through experience of seeing no ppn shown inland by a model but showers still popping up.

 

Yep, already been seeing daytime convection over land in the last week or two, and that's without the aforementioned ridiculous lapse rates. Will certainly be a learning curve for how the models deal with it.

Share this post


Link to post
Share on other sites

Yes - a sublime ICON at 120hrs...

 

Certainly fast forwards the cold - what we want to see :)

 

icon-0-120.png

Share this post


Link to post
Share on other sites
Just now, moorlander said:

question for you @Nick L 

is there any type of chart/graph that i can look at that will show this or is it a case of now casting

Can't say I know of such a thing unfortunately, if anyone does it would be useful. The figures I quoted are a rough rule of thumb!

Share this post


Link to post
Share on other sites
1 minute ago, rory o gorman said:

I thought have thought the lack of moisture would negate the laspe rates , surface thermals ? 

Usually there is enough moisture aloft in our maritime climate to support high based convection with warming from below, even if the continental surface flow has dried out inland from the North Sea.

Share this post


Link to post
Share on other sites
2 minutes ago, Nick F said:

I would have thought that more strength in the sun as we approach early March may provide enough shallow heating above the ground to support some convective development inland as well - given how steep the lapse rates will be, something the models may not simulate well - through experience of seeing no ppn shown inland by a model but showers still popping up.

 

Agreed, I can remember a few past examples in which a predicted (by models) dry day was interrupted at least once by those magnificent sort of billowing yet at the same time wispy clouds, leading to a sudden transition at ground level from clear to snowing readily. 

Admittedly some of those may be from my dreams but I assure you it has happened in reality at least once this century :D.

So yes, should be lesson one of global model reading really; don't trust them to handle convective showers.

Share this post


Link to post
Share on other sites
7 minutes ago, ITSY said:

96hours away people. Good start to the 18z runs from the Icon...

5A0FC0F6-F5D7-4991-8E38-279B720EEE7D.png

High further north, cold air pool further westward by about 6hrs. Marginally better wind angle. Decent improvements even by 108.

here is 120 on 12 (first chart) vs 18

BE892320-47B6-4140-8641-B5B4C4CEAEE2.png

F30485C1-4E60-4266-9A60-B893550DF201.png

looking very good. Italian low is slightly further north and more energy going it into from the lows in the Atlantic. I think its possible we might see more energy go under.

can you imagine the chaos if there was stronger Italian low increasing the pressure gradient/wind speeds and driving the sub -18 uppers into us.

Share this post


Link to post
Share on other sites
1 minute ago, Nick F said:

Usually there is enough moisture aloft in our maritime climate to support high based convection with warming from below, even if the continental surface flow has dried out inland from the North Sea.

0 /15 c spread will be quite interesting to see the the results of LCL ect  .Forecast Soundings will come into reach soon certainly worth a look over. 

Share this post


Link to post
Share on other sites
4 minutes ago, pages said:

looking very good. Italian low is slightly further north and more energy going it into from the lows in the Atlantic. I think its possible we might see more energy go under.

can you imagine the chaos if there was stronger Italian low increasing the pressure gradient/wind speeds and driving the sub -18 uppers into us.

Interesting observation - the low in question is actually much further north on the 18 ICON than the 12 GFS, though even by +48 it is slightly further north on the GFS (18z run) this evening. It would certainly accelerate the cold westward by strengthening the mean easterly across Central Europe, which would be no bad thing at all for early cold onset. Just another thing to look out for...

Edited by ITSY

Share this post


Link to post
Share on other sites

About the coldest ever sustained ensemble I have ever seen. 

Cold looks like it will keep reloading if each run. 

 

 

t850Aberdeenshire (1).png

Share this post


Link to post
Share on other sites

GFS 18z looking largely unchanged in the short term from the 12z.

Share this post


Link to post
Share on other sites

GFS possibly a little further north at T66, 18 and 12:

gfs-0-66.png?18

gfs-0-72.png?12Or maybe faIrly close on second look.

Edited by Mike Poole

Share this post


Link to post
Share on other sites
8 minutes ago, Dbarb said:

 

Edited by Dbarb

Share this post


Link to post
Share on other sites
1 minute ago, blizzard81 said:

Lovely 120hr fax chart 

fax120s.gif

Looks like an East/South Easterly?

Share this post


Link to post
Share on other sites

Not much in it but the flow is very slightly better aligned at 96 hrs

gfsnh-0-96.png?18

Share this post


Link to post
Share on other sites

The trend this evening so far is to push everything further north and West again. I wonder if the models have under estimated this because there's definitely momentum to build the cold in much quicker again!

Share this post


Link to post
Share on other sites
2 minutes ago, Neilsouth said:

Looks like an East/South Easterly?

Is that a trough on the 120h fax to the east of Scotland?

Edited by howham
Update

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...