Jump to content
Cold?
Local
Radar
Snow?

Model output discussion - into July 2020


Recommended Posts

3 minutes ago, Man With Beard said:

ECM clusters for Saturday morning. Not what forecasters want to see! A perfect split between runs which introduce westerly source to northern areas only, and runs which will bring a westerly source to all areas! (Follow the lines)

ec-ens_nat_z500scenarios_2020080400_096.

A 5-10 degree difference possible between the clusters in central/eastern areas, at just T96!

I think that tells us all we need to know about making any predictions, or proclaiming that one model has got this right.

  • Like 2
Link to post
Share on other sites
  • Replies 2.7k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

...Like shoals of fish they are starting to point the other way in midstream...👸 Recent NWP, up to the start of this week, had seemed suspicious the way it had reverted to extrapolating the defaul

Posted Images

10 minutes ago, Evening thunder said:

 

Friday the apparently 'locked in' hot day is looking sketchy for some, ECM has a band of cloud here and 21C in the afternoon.
image.thumb.png.561e78901da94638bd94487032b615dd.png

Although it is hot for most of lowland England.

I don't think you can say there hasn't been any change/drift in the models.. well unless this thread's impression on previous days of a prolonged, widespread or record breaking heatwave coming was a bit off 😉

It's not a bad outlook, just again a little disappointing if you wanted something notable away from the SE.
 

Must admit I don't really see it on the temp charts unless you live in the SE. A lot of thundery activity on this run though.

Sorry, that’s my imby SE bias speaking.

Link to post
Share on other sites

Models often struggle with cloud cover and project temperatures far too low as a result. We saw that from some of the models last Friday. That’s where the higher resolution models should do better but can still be off.

  • Like 3
Link to post
Share on other sites
Just now, MattStoke said:

Models often struggle with cloud cover and project temperatures far too low as a result. We saw that from some of the models last Friday. That’s where the higher resolution models should do better but can still be off.

A few models showed quite a lot of cloud last Friday, and in the end it wasn’t an issue until late afternoon after peak heatIng.

  • Like 1
Link to post
Share on other sites
9 minutes ago, Djdazzle said:

A few models showed quite a lot of cloud last Friday, and in the end it wasn’t an issue until late afternoon after peak heatIng.

I think Arpege & GFS did Ok last week, GFS actually called the cloud through central southern areas very early. I have a feeling friday could be annoying for areas west of the IOW.....  

Link to post
Share on other sites
2 hours ago, johnholmes said:

It is not surprising there are variations in the synoptic models. The 500 mb charts cannot agree from day to day. If the atmosphere's pattern is uncertain at 500 mb then hardly surprising that the surface has issues in continuity. All 3 this morning go back to the charts showing blocking and troughing such that the heat MIGHT continue for more than 1-3 days?

Fence sitting time for jh!

I was hoping your experience would shed some light on this sea of uncertainty after Friday.

To me, the NOAA 500mb have been consistent, and have illustrated the development very well of the building high. The day to day changes have been slight but have evolved smoothly imho.

However, i dont think either of the current ECM or GFS outputs for the 6-14 day timeframe marry up too well to what the NOAA charts forecast. The GFS in particular is very wide of the mark imho.
The NOAA charts show high pressure roughly in the north sea, with the highest height anomaly between Scotland and Norway, with troughing between Northwest Spain and the Azores, a light southwesterly mean flow over the UK.
The GFS chart is for t192, so mid point on the NOAA 6-10 day chart. The GFS does not follow what the NOAA chart does imho..

So whos right? or which suite is most likely to be nearer the mark?.. Ill back the consistent NOAA any day, but the GFS cannot be ignored, this conflict though is a headache for us amateur bloggers! lol

 

610day.03.gif

  • Like 3
Link to post
Share on other sites

I would not disagree with your comments mushy, Noaa is usually closer to the 'average' chart in the 6-10 day period than GFS. It has, as you comment, also been the more consistent over the past few days. So yes I'd back the Noaa version if I fell off the fence!

Its 8-14 keeps a similar pattern also.

  • Like 6
Link to post
Share on other sites

Again the 06Z Arpege increases cloudiness and drizzly bits of rain through Wed/Thurs and there's certainly a shift towards more marginal conditions. On Wednesday especially it has a swathe of pretty low temps 16-19C for much of the day from Dorset up into parts of the home counties under drizzly rain and cloud that never really clears, very little in the way of the models improving conditions on any of the days this morning, one way trend currently - yes thats a bit of a broad brush statements but its hard to find evidence to the contrary.

  • Like 1
Link to post
Share on other sites
14 minutes ago, Alderc said:

Again the 06Z Arpege increases cloudiness and drizzly bits of rain through Wed/Thurs and there's certainly a shift towards more marginal conditions. On Wednesday especially it has a swathe of pretty low temps 16-19C for much of the day from Dorset up into parts of the home counties under drizzly rain and cloud that never really clears, very little in the way of the models improving conditions on any of the days this morning, one way trend currently - yes thats a bit of a broad brush statements but its hard to find evidence to the contrary.

Definitely been a slight pulling back on temps today. Latest BBC has 28 for Thursday (down from 30c), and 34c Friday, down from 35c. 32c Saturday and down to 26c Sunday. Still a very warm spell.

Link to post
Share on other sites

I know its a consequence of being on the edge of a massive ocean but does anywhere suffer as regularly as the UK with these macro systems that seem to make such a massive difference across 100-200miles, everything is always so marginal....its just annoying. 

  • Like 2
Link to post
Share on other sites
21 minutes ago, JON SNOW said:

Whoa Daddy, just look at the GEFS 6z mean..sensational isn’t it?😍😜☀️

7F506464-8FC6-406E-9EF8-1CA41E672562.thumb.png.96450adfa60323e00b3e02a4a616f039.pngBC05B300-CE90-450E-B932-40B196344865.thumb.png.71647b759d6af2b1d890e222549c470a.pngE0AF75BF-F73E-495F-B211-38A39248FDD6.thumb.png.0faeb6ea455a6d918f8982155278a2e4.pngABF3CEE1-C028-4C5D-9C63-52E6F4CEDDD8.thumb.png.c79f4c7f8ca4acc5398aa563d514f6ce.pngF2D1A3DB-1A0D-4739-94B8-2DB58EB177F8.thumb.png.8930863f8b9a21d0d92be60b5a7d5dee.pngBE0D7661-9F12-4887-A03C-41EC27F09BD8.thumb.png.98a27b2e9e495b28da2e6f1f98232dfe.png

Is it?.... theres a northeasterly/easterly draft on those charts, that suggests north sea cloud and cooler temps for at least eastern districts. We have seen this before when high uppers are undercut at surface level by cooler air. Caution is needed here before cracking out the champagne..

  • Like 3
Link to post
Share on other sites
17 minutes ago, mushymanrob said:

Is it?.... theres a northeasterly/easterly draft on those charts, that suggests north sea cloud and cooler temps for at least eastern districts. We have seen this before when high uppers are undercut at surface level by cooler air. Caution is needed here before cracking out the champagne..

Sea surface temperatures are at least at their highest this time of year, so the impact on surface air temperature is at its minimum.

  • Like 1
Link to post
Share on other sites
45 minutes ago, JON SNOW said:

Whoa Daddy, just look at the GEFS 6z mean..sensational isn’t it?😍😜☀️

7F506464-8FC6-406E-9EF8-1CA41E672562.thumb.png.96450adfa60323e00b3e02a4a616f039.pngBC05B300-CE90-450E-B932-40B196344865.thumb.png.71647b759d6af2b1d890e222549c470a.pngE0AF75BF-F73E-495F-B211-38A39248FDD6.thumb.png.0faeb6ea455a6d918f8982155278a2e4.pngABF3CEE1-C028-4C5D-9C63-52E6F4CEDDD8.thumb.png.c79f4c7f8ca4acc5398aa563d514f6ce.pngF2D1A3DB-1A0D-4739-94B8-2DB58EB177F8.thumb.png.8930863f8b9a21d0d92be60b5a7d5dee.pngBE0D7661-9F12-4887-A03C-41EC27F09BD8.thumb.png.98a27b2e9e495b28da2e6f1f98232dfe.png

Sensational for those South of Milton Keynes, Not so sensational for those living in the West. 

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

Sea surface temperatures are at least at their highest this time of year, so the impact on surface air temperature is at its minimum.

True, but north easterlies are never that warm unless they are sourced from the continent.

Link to post
Share on other sites
26 minutes ago, Djdazzle said:

True, but north easterlies are never that warm unless they are sourced from the continent.

9EE58994-1BD4-4CDA-BD7D-14C8FC4FE7DC.thumb.gif.cb5794635bffdbf720a3de066af51601.gifFB5DBD1D-298A-441B-AC35-A74E53DBCA21.thumb.gif.47e11337e02ef14400ee08b7bbf0f1a9.gif
 

Case in point....850s at 15c in the NE, 17c temps.

  • Like 1
Link to post
Share on other sites
45 minutes ago, MattStoke said:

Sea surface temperatures are at least at their highest this time of year, so the impact on surface air temperature is at its minimum.


 

12 minutes ago, mb018538 said:

9EE58994-1BD4-4CDA-BD7D-14C8FC4FE7DC.thumb.gif.cb5794635bffdbf720a3de066af51601.gifFB5DBD1D-298A-441B-AC35-A74E53DBCA21.thumb.gif.47e11337e02ef14400ee08b7bbf0f1a9.gif
 

Case in point....850s at 15c in the NE, 17c temps.

think that addresses that...

I just remember being caught out several times before in similar situations by setting too much faith in high uppers only to be let down. Hence "caution".

Link to post
Share on other sites

Hope we see similar looking  blocked charts  throughout the winter,regarding later this week,

I would always back UKMO over gfs ,you only have to look back over recent years too see how many times it  was  correct over the gfs.,anyone saying gfs is ‘on top of the throne’ or words to that affect is basically trolling.,just check the verification stats for a start....

  • Like 2
Link to post
Share on other sites
4 minutes ago, SLEETY said:

Hope we see similar looking  blocked charts  throughout the winter,regarding later this week,

I would always back UKMO over gfs ,you only have to look back over recent years too see how many times it  was  correct over the gfs.,anyone saying gfs is ‘on top of the throne’ or words to that affect is basically trolling.,just check the verification stats for a start....

I agree, but there have been the odd "upsets" where GFS has pulled off a shock victory! Let's hope things go by the form book this time.

Edited by Djdazzle
  • Like 2
Link to post
Share on other sites

I wish this possible heat would turn up in north east England as yet again, the summer here has been dire.

Currently 13c, mid summer afternoon, under thick cloud. Not the first time either, wondering if it is almost record breaking cold?

The forecast yesterday on local radio was 18c today and warm!?? How can temperatures below normal be classed as warm? There seems to be a reticence about saying cold or below average!

  • Like 2
Link to post
Share on other sites

ARPEGE just out in French view. Currently going for another one day wonder with that 36C marker back again in the SE for Friday. 29C for Thursday and Saturday.

arpege-31-54-0.png?04-17  arpege-31-78-0.png?04-17  arpege-31-102-0.png?04-17

In my opinion, the ARPEGE doesn't really start to get a grip on things until T72, so I wouldn't get too confident on Saturday's chart yet.

 

Edited by Man With Beard
  • Like 3
Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...