model discussion Model output discussion 11th July onwards

[Mike Poole]

Good set of 12z runs tonight, for settled weather into the heart of September.  T96 - Friday - looks like an incursion of lower pressure, but I can’t see it actually being that wet - just thunderstorms bubbling up in the afternoon.  

Moving past that, T144 on the main models:

There seems to be model agreement on a cut off low to the southwest fuelling a high pressure in the vicinity of the UK, slightly less strong on GEM than the others but alls good for the start of next week - which I’m off work for

[mb018538]

September doing it’s usual trick of recent times and outgunning august again in would seem. A very quiet looking ecm run with high pressure soon returning.

[Guest]

56 minutes ago, MATTWOLVES said:

Fingers crossed Chris..  you could be looking good  

Unfortunately though weekend starting to look really cold, could be struggling to get into the teens in places. Not sure how both ECM and GFS have such desperately cold surface conditions…Saturday bearable across the south but dire for all on Sunday.

 

[MP-R]

3 minutes ago, Alderc said:

Unfortunately though weekend starting to look really cold, could be struggling to get into the teens in places. Not sure how both ECM and GFS have such desperately cold surface conditions…Saturday bearable across the south but dire for all on Sunday.

 

Stagnant heavy rain would be the only explanation. A few runs have shown a front wavering in situ over the south on Sunday.

[Guest]

24 minutes ago, MP-R said:

Stagnant heavy rain would be the only explanation. A few runs have shown a front wavering in situ over the south on Sunday.

Doesn’t look like more than a few showers? 
 

 

[Cambrian]

The disappointing temperatures currently outputted by the GFS for next Sunday might be the result of chilly temperatures at dawn over Scotland, Northern England and northwest Wales

 

This air filtering slowly south all day on a gentle northerly under slow moving clumps of showers 

    

 

(looks like there might be a small trough behind all this, there’s a little kink in the isobars over southern Britain on the 3pm chart  - 

and all this along with only near-equinox sun strength if and when it breaks through.

Doubt very much that it will be like that in the event, long way off for such a small feature to be forecast right.

 

[MATTWOLVES 3]

Quick one from me regarding tonights EC46.

Not much to report on the coming week what the main models suggest...moving forward looks like a more prominent far North to South split...The conditions look promising for that final 3rd of the month,with only the far NW being subject to lower pressure at times.

Worth noting the 7 month anomalies have been updated recently,and October looks like it could be a warmer than average month!

Now interestingly it flags up December and January as being colder than average quite widely!

Trend setter or to far off to know! Either way good to see those early signs pointing this way!  

[Kentspur]

11 minutes ago, MATTWOLVES said:

Quick one from me regarding tonights EC46.

Not much to report on the coming week what the main models suggest...moving forward looks like a more prominent far North to South split...The conditions look promising for that final 3rd of the month,with only the far NW being subject to lower pressure at times.

Worth noting the 7 month anomalies have been updated recently,and October looks like it could be a warmer than average month!

Now interestingly it flags up December and January as being colder than average quite widely!

Trend setter or to far off to know! Either way good to see those early signs pointing this way!  

Looks average to me Dec to Feb or have u seen a monthly breakdown? Yes October does continue to look warn at present 

[Kentspur]

Just now, Kentspur said:

Looks average to me Dec to Feb or have u seen a monthly breakdown? Yes October does continue to look warn at present 

 

[Methuselah]

GFS 00Z run isn't at all bad this morning:      

                                                                                

                                                                                

Plenty of warm, dry weather on offer -- and very little in the way of rain?

[mb018538]

A quick perusal of the 00z offerings..

Quiet on the UKMO 00z run as low pressure spins away to the SW. This starts to waft some very warm air into the south again by Tuesday - leading to a big contrast. 850s up at 15c in Devon/Cornwall....and down at a chilly 4c in NE Scotland.




GFS also very quiet with high pressure over the UK on Monday, so some disagreement on the UKMO projection:. There is also some warmth by midweek:



GEM makes much more of the upper low feature, and stalls it across the south. Net result is slow moving heavy rain:



ECM offers yet another different solution, though isn't a massive rainmaker:

[Frosty.]

13 hours ago, jon snow said:

The Gfs 12z operational shows another plume mid month, I guess with the type of pattern we have, another plume is probably a reasonable bet in approx the timeframe shown? ⛈ 

I mentioned yesterday about the chances of another plume associated with the current pattern, and hey presto, the Gfs 0z op gives us one mid month!…and then potentially another one!!    ⛈ 

 

[Eagle Eye]

On 07/09/2021 at 07:53, jon snow said:

I mentioned yesterday about the chances of another plume associated with the current pattern, and hey presto, the Gfs 0z op gives us one mid month!…and then potentially another one!!    ⛈ 

 

Hard to believe how bad August was but fortune favours the patient and finally we're having some luck. 

Edited September 7, 2021 by Eagle Eye

[Frosty.]

The ECM 0z op certainly doesn’t support my plume idea next week that the Gfs 0z op shows!…well, you win some, you lose some!   

 

[MATTWOLVES 3]

11 hours ago, Kentspur said:

Looks average to me Dec to Feb or have u seen a monthly breakdown? Yes October does continue to look warn at present 

Monthly breakdown mate.. the grey shading indicating slightly negative anomalies. I've very often seen it indicating orange shading for that time of the year,so I'm kind of taking it as a positive at this early stage! 

[mb018538]

11 minutes ago, jon snow said:

The ECM 0z op certainly doesn’t support my plume idea next week that the Gfs 0z op shows!…well, you win some, you lose some!  

 

Op was on the cool side of the pack, so not guaranteed by any means!

Latest ECM weeklies are keen to keep some form of ridging over or very close to the UK in the coming couple of weeks.




A blocked outlook on the frequency forecast....and the MJO may start to cycle through 4/5/6 later in the month, which are usually better for the UK.  

 

We're currently experiencing good weather in a -ve AAM regime....which is mainly due to hurricanes messing around with the jet/wavelengths that you'd usually expect in a -AAM regime. Hurricanes very much the UK's friend at present and for this hot weather now. 

[Frosty.]

16 minutes ago, mb018538 said:

Op was on the cool side of the pack, so not guaranteed by any means!
 

Don’t think I said it was guaranteed did I?… …I merely said the ECM op didn’t support the Gfs op plume idea mid month…of course, this doesn’t preclude another plume next week! 

Edited September 7, 2021 by jon snow

[mushymanrob]

More anticyclonic conditions emerging, a dry theme continues (after this weeks showery spell) and we could well get more warm continental air on a southeasterly ..

 

[damianslaw]

1 hour ago, mb018538 said:

Op was on the cool side of the pack, so not guaranteed by any means!

Latest ECM weeklies are keen to keep some form of ridging over or very close to the UK in the coming couple of weeks.




A blocked outlook on the frequency forecast....and the MJO may start to cycle through 4/5/6 later in the month, which are usually better for the UK.  

 

We're currently experiencing good weather in a -ve AAM regime....which is mainly due to hurricanes messing around with the jet/wavelengths that you'd usually expect in a -AAM regime. Hurricanes very much the UK's friend at present and for this hot weather now. 

This time of year quite difficult to forecast due to ex hurricane activity which is countering other factors that otherwise would probably portend to much more unsettled and cooler conditions. First time this season heights have collapsed into central Europe to pull in a warm SE feed. Hence the lack of any notable warmth in the SE. Without the hurricane activity I suspect heights would have held much further north and we would have been at the mercy of the shallow trough feature anchoring through southern parts as we have seen so often this year. Again forecast further into September going against grain of the year, holding low heights far to the SW with heights sinking further east and south again to produce a warm settled outlook.

Sometimes we do well from hurricanes other times but so..  

[Scorcher]

1 hour ago, mushymanrob said:

More anticyclonic conditions emerging, a dry theme continues (after this weeks showery spell) and we could well get more warm continental air on a southeasterly ..

 

Long may it continue. We spend enough of the year in jumpers and coats.

Truly wonderful day today.

[MATTWOLVES 3]

3 hours ago, Scorcher said:

Long may it continue. We spend enough of the year in jumpers and coats.

Truly wonderful day today.

Speak for yourself mate,I don't even wear jumpers or coats In winter...probably a vanity thing though from lifting weights

GFS 6z seems to have Heights to the East of us next week...and as long as that theme Continues,we will continue to tap into warmer continental air!

Tbh it looks good again beyond later this week/weekend.

Check the fridgid air over Greenland! That's getting ready to pounce later this year! I sincerely hope!

[Methuselah]

Och well, I'm back from another day's Extreme Weeding, and the GEFS 06Z ensembles look rather dependent on ex-hurricanes right now:

    

Daytime maxima go up and down only slightly slower than Jordan's panties!

[Methuselah]

And would I take this for the 23rd of September? You can bet you life I would!

      

[sheikhy]

Very dry runs again this evening from the main three models!!cant believe how long this dry spell is going on for!!got a few showers on thursday but apart from that any rain that is forecasted is going to be light and hardly gona do anything to the very dry ground we have currently!!

[Mike Poole]

9 minutes ago, sheikhy said:

Very dry runs again this evening from the main three models!!cant believe how long this dry spell is going on for!!got a few showers on thursday but apart from that any rain that is forecasted is going to be light and hardly gona do anything to the very dry ground we have currently!!

Yes, very good @sheikhy!

The reduction in pressure Thursday - Friday looks like being fairly innocuous, may bring thunderstorms to some in the afternoons.  But from then on, there is cross model agreement on a decent warm settled spell.  Picking up the models at T192:

Yes, as you would expect at that range there are differences, but all have some kind of high to the east being the main influence on our weather, which we have wanted since that early July hot spell, but it was never delivered.  High confidence now for decent weather for next week, maybe longer.