Jump to content
Cold?
Local
Radar
Snow?

Model Output Discussions 12z 08/03/17


Recommended Posts

49 minutes ago, Summer Sun said:

I wonder if GFS is under doing the temps as early as Monday it shows a high of 21c the beeb are saying 24c

ukmaxtemp.png

456456.thumb.png.71689001002a7544bbb8b09fc7a198a9.png

 

GFS is clearly underestimating max temperatures again, by a good 3-4C. Happens regularly.

  • Like 3
Link to post
Share on other sites
  • Replies 2.1k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Much as previously intimated, I'm no longer inclined to posting much at all on these threads, winter or summer, but admittedly the perspectives offered sometimes prove too much to resist responding to

Do they?  Oh ok, right you are then. You could of course have quoted said "way of the pear" musings by way of illustration - but I accept that would conflict with the real purpose of the post and

So, the steadily improving picture emerges, from a sea of apparent doubt, and as suggested is timed quite nicely for the approach of summer That background ENSO neutral > weak Nino signal impr

Posted Images

GEM slightly unreliable but a serious run coming from the ECM (oddly the evolution is pretty much the same as the GEM)

ECM1-120.GIF?20-0   ECM1-144.GIF?20-0   ECM1-168.GIF?20-0

ECM0-120.GIF?20-0   ECM0-144.GIF?20-0   ECM0-168.GIF?20-0

850s of 14-16C across England and Wale with a thundery plume developing for the weekend, a 30C run this one with temperatures rising day on day from Wednesday onwards.

I guess the downside is that is more progressive in breaking the ridge down with fresher conditions pushing east on Sunday (The east could hang on to high twenties), in essence this is quicker but with more of a bang both in terms of heat and storm potential and still a solid few days of very warm weather.

Edited by Captain Shortwave
  • Like 6
Link to post
Share on other sites

Yes Ecm now looking very much like the lateat meto update which spoke of the breakdown as we head thru the weekend, still plenty of warmth to look forward to before then..( thats if ecm is correct of course).

  • Like 1
Link to post
Share on other sites
21 minutes ago, Captain Shortwave said:

I guess the downside is that is more progressive in breaking the ridge down with fresher conditions pushing east on Sunday (The east could hang on to high twenties), in essence this is quicker but with more of a bang both in terms of heat and storm potential and still a solid few days of very warm weather.

Never a truer word CS. At 18z Saturday the thundery low is quite shallow just SW of Ireland and thus the southerly drift giving the possible 30C. This changes quite rapidly and by 12z Sunday the low has deepened and is just NW of Ireland and most of Britain is in an unstable westerly with the temps cooling rapidly west-east. Most of the thundery rain misses the UK. The low then tracks north east leaving the door ajar to the Atlantic. But all of this is eight days down the road and this will change over the next few runs and we may by then even get some cross model agreement. But it does look like being a fine week irrespective apart from Scotland on Monday.

ecm_mslp_uv850_eur_8.thumb.png.246c8c88a02fc0bad29534a847488f0a.pngecm_mslp_uv850_eur_9.thumb.png.e372db3814eba07f21661416b940c38b.pngecm_t850a_5d_eur_11.thumb.png.b91f18bcf8f27c8dc544f0128751b0f8.png

Edited by knocker
  • Like 5
Link to post
Share on other sites

Looks great to me - this complete flip to waem/hot weather has shown how the models and weather can make a mug of everyone. A few days ago nothing pointed to this imminent heat, and we were resigned to more disappointing weather. A couple of small synoptic changes and everything is falling into the right place. How things change. Bring on those mid to upper twenties - Bliss :)

  • Like 8
Link to post
Share on other sites

Well it has to be said the ecm and gfs are not in bad agreement this morning vis the weekend.

It has the low drifting north over Ireland on Saturday to be Hebrides 00z Sunday accompanied by what looks like some quite active convective activity (just a general observation at this range). Thus the UK remaining in the southerly drift with temps still possible touching 30C in places. From here the low tracks NE into Scandinavia and the Azores ridge stretches north east with the eastern half of England just hanging on to temps around 28C.

ecm_mslp_uv850_natl_8.thumb.png.2b78f3f40f9d1c46b42b26c293247087.pngecm_mslp_uv850_natl_9.thumb.png.c6c55781c7b69e59e08fd11f6ee8e554.png

  • Like 3
Link to post
Share on other sites

The ECM just had to push it one step further. The magical 20C 850hpa mark gets really close by Sunday morning before the cold front makes its move, showing potential (personal judgment without looking at their official temperature charts) for a Gravesend 90F by Sunday lunchtime.

No doubt this is the extreme end of the range - but agreement growing on a set-up that by the end of the week would produce at least 27C-28C in the hottest spots and 24C-28C pretty widely inland. Summer is on its way!

Not a little thundery potential, too.

  • Like 7
Link to post
Share on other sites

Just subtle differences in regards to when that shallow Iberian low moves north through the Bay of Biscay and up through the western side of the UK, the ECM tracking this more slowly north and hence allowing a hot and sultry day in the east.

ECM1-168.GIF?21-12   gfs-0-168.png

The GFS a little quicker but interestingly we don't really see the decline of the Euro ridge with the ridge being re-enforced by the Azores ridge which moves in quickly during the end of the bank holiday weekend. The ensembles seem less keen with a NW/SE split and a west/southwest flow though of course the operationals could be more on the money.

Otherwise Sunday offers the potential of seeing temperatures touch the low thirties, given the ECM has 850s up to around 18C over the south, just a question of whether we keep the clear skies for long enough or whether we see a more widespread breakdown during the day.

Otherwise this week looks very nice with sunshine and light winds with the temperatures rising further from Thursday onwards and to be honest the temperatures before then look pretty decent. 

  • Like 9
Link to post
Share on other sites

The May record of 32.8c last set in 1944 would be under real threat if GEM is right

gem-9-132.thumb.png.d7684ec6d061ad786598da8c2a02bdc1.pnggem-9-156.thumb.png.142725435139d352979e40c6780e55a5.png

Horsham, Tunbridge Wells & Regent's Park, North-West London hold the joint record currently

  • Like 2
Link to post
Share on other sites
1 minute ago, Summer Sun said:

The May record of 32.8c last set in 1944 would be under real threat if GEM is right

gem-9-132.thumb.png.d7684ec6d061ad786598da8c2a02bdc1.pnggem-9-156.thumb.png.142725435139d352979e40c6780e55a5.png

Horsham, Tunbridge Wells & Regent's Park, North-West London hold the joint record currently

I think I'm right, from memory, that GEM overestimates plumes a little in summer? Or was that NAVGEM??

Link to post
Share on other sites
10 minutes ago, Man With Beard said:

I think I'm right, from memory, that GEM overestimates plumes a little in summer? Or was that NAVGEM??

The plume that kicked off July 2015 saw GEM overcook the 850s by a couple of degrees, yet end up closer to the mark with the highest UK temp. Broader temps were a bit overdone though so it seems the overcook error allowed the model to depict some values close to what was actually a very localised UK peak, by negating the overlooking of localised heat build that models tend to exhibit.

It was an exceptional event of course, but then this could be too if it all comes together just-so.

GEM is likely going even further beyond consensus than usual on this occasion though, as it aligns the shallow low perfectly N-S while making it unusually elongated. The chances of that have to be pretty slim.

So... good chance of a localised 32*C in usual hotspots if current consensus for overall setup holds... But dependent on timing of thundery breakdown as has already been suggested on here :)

Edited by Singularity
  • Like 4
Link to post
Share on other sites
28 minutes ago, Man With Beard said:

I think I'm right, from memory, that GEM overestimates plumes a little in summer? Or was that NAVGEM??

NAVGEM took us into the low 40s last summer I seem to remember before obviously backing down to the 30s

  • Like 1
Link to post
Share on other sites

For reference when the 20C 850hpa line clipped the UK in 2003 we hit our hottest ever temperature. Obviously we won't get near that, but if we do get the 20C line then 32C is not out of the question.

 

Rrea00220030810.gif

Edited by Snowy L
  • Like 2
Link to post
Share on other sites
16 minutes ago, Snowy L said:

For reference when the 20C 850hpa line clipped the UK in 2003 we hit our hottest ever temperature. Obviously we won't get near that, but if we do get the 20C line then 32C is not out of the question.

 

Rrea00220030810.gif

The same thing happened on July 1st 2015. We got 37.1c out of the 20c isotherm, and it could've got even higher, had it have not been scuppered by a period of mid level cloud trundling by. I remember it so well! 

May record could be under a serious threat if we keep getting upgrades like this! 

  • Like 1
Link to post
Share on other sites

The EPS 850mb means. Of course if the low tracked just a fraction east on Saturday it would be a different ball game :shok:

ecm_eps_t850a_5d_nh_8.thumb.png.978ac1e0067cfcf4156e915161a89a09.png

 

Edited by knocker
  • Like 5
Link to post
Share on other sites
5 hours ago, Polar Maritime said:

Some very nice late Spring warmth showing across the models this morning, Especially into the Bank Holiday weekend where temps could touch 27/28c quite widely.. Some Temp snapshots from the Net/Wx in-house Model.. 

a.thumb.png.643d4c7c570f134b4b72a2c119668680.pngb.thumb.png.0d3c4fb4da1bc5e874a3571f527d7e90.pngc.thumb.png.d768f476c65335886dd092c5f5165f76.png

 

Would say more Summer warmth! especially as models tend to underdo temps

  • Like 1
Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...