Model Output Discussion 18z 28/07/13

[Buzzit]

Model output this week has changed as much as evidence on CW use in Syria. Forget about trying to call anything for future periods until some time next week at the earliest.. at which point we should have a much clearer idea of what the dominant weather type will be for the middle of September.

Easiest model summary in ages at the moment = rain for everyone throughout the weekend !

Edited September 5, 2013 by Buzzit

[Frosty.]

Well the gfs sends the uk nosediving into autumn weather from tomorrow until the end of the run, unlike the 0z, there is no significant high pressure build in FI on the 6z, just a weak atlantic ridge pushing east through the second half of next week separates us from the next trough, so it's an unsettled and cool 6z although the second half of next week looks drier and brighter for the south & east before the next mass of rain pushes in off the atlantic by the end of next week, troughs are drawn to the uk like a magnet on this run, it's interesting that the uk could be so unsettled when the atlantic (for the most part) is so benign and filled with high pressure, kind of unlucky for us if this verifies.

Edited September 5, 2013 by Frosty.

[Scorcher]

 

 

Latest ECM 00Z ensembles also show much cooler temps next week. Big rise again from the op run on the 13th but very much a outlier.

 

 

 

The rise in temperatures would make sense as the high drifts east- it would only start off cool and would get warmer through the week, particularly further south. Of course the build of high pressure may not happen as shown by the op but with high pressure moving across us it would get warmer.

[Frosty.]

The good news is the GEFS 06z mean is significantly less bad than the op run and looks rather warmer with a mix of sunshine and showers before trending drier and sunnier in the south later as pressure slowly rises but cooler and more zonal for the north of the uk later.

 

 

 

 

 

 

 

 

 

 

 

 

 

[Frosty.]

The GEFS 06z control run is a triple x rated horror until well into FI but towards the end high pressure builds in.

Edited September 5, 2013 by Frosty.

[Frosty.]

Well the Ecm 00z ensemble mean is probably the best of a bad bunch, with the exception of the ecm 0z op run, high pressure eventually moves closer to the southwest/south so it would become relatively drier and warmer across the southern half of england & wales compared to the north of the uk where the trend is towards a more generally cooler and zonal outlook.

[Frosty.]

The best news today is from the latest met office update, which sounds very promising for the southern half of the uk from the middle of next week onwards, becoming generally drier and warmer with sunny spells and lighter winds but with a risk of overnight fog, this is a much better outlook than the gefs mean is showing today, it's probably more in line with the ecm 0z ens mean/op runs and far superior to the gfs operational/control output, only the northwest corner of the uk is likely to trend more unsettled with a strengthening southwesterly airflow in the medium range with most of the southern half of the uk becoming more benign with warm sunny spells but cool foggy nights.

Edited September 5, 2013 by Frosty.

[bluearmy]

couple of points :

 

the ecm op, although one of the warmest runs in fi, is not an outlier.  i recall the current period had ecm op showing much warmer temps for london in fi than 90% of the ens and it was proved right. 

 

the week 2 naefs shows the high anomoly near the uk becoming quite impressive for that timescale whilst the jet trundles well to our nw. dont be surprised to see the hp theme continue well beyond mid month. 

 

all in all, no certainty how long the w/end trough will hang around next week, but given the better outlook thereafter, if ecm op remains bullish on the ridge in its next run, i would be pretty well ready to call it as pretty likely.

[Frosty.]

couple of points :

 

the ecm op, although one of the warmest runs in fi, is not an outlier.  i recall the current period had ecm op showing much warmer temps for london in fi than 90% of the ens and it was proved right. 

 

the week 2 naefs shows the high anomoly near the uk becoming quite impressive for that timescale whilst the jet trundles well to our nw. dont be surprised to see the hp theme continue well beyond mid month. 

 

all in all, no certainty how long the w/end trough will hang around next week, but given the better outlook thereafter, if ecm op remains bullish on the ridge in its next run, i would be pretty well ready to call it as pretty likely.

I would really like to see what mogreps is showing, we can only view part of the jigsaw puzzle whereas the met office have all the tools they need and then some.

[Summer Sun]

Slight changes from GFS finally it hasn't moved fully towards ECM and UKMO yet but its getting there slowly

 

Edited September 5, 2013 by Summer Sun

[ANYWEATHER]

Slight changes from GFS finally it hasn't moved fully towards ECM and UKMO yet but its getting there slowly

 

You keep banging on about high pressure, and in the output tonight from the gfs and even from its output today, it shows  clearly, that high pressure wont be in charge in the more reliable timeframe,,,,

[Frosty.]

This chart from the Gfs 12z reminds me of when moses parted the red sea..but the similarity ends there

[Summer Sun]

The weekend is looking rather unsettled it has to be said GFS has almost produced a rather rude chart as well for tomorrow

 

 

 

The north looks the wettest tomorrow with parts of the south getting only light rain

 

 

Saturday sees an improvement with the rain more in a sunshine and showers set up

 

 

Again the SE is one of the the driest spots in the UK

 

Sunday sees continued improvements

 

 

Into next week and temperatures are on the up again espically in the south with high teens widely and some getting into the low 20's

 

Edited September 5, 2013 by Summer Sun

[Yarmy]

Just for our Yarmouth-based members:

 

 

 

Triangle of doom, indeed

[Summer Sun]

As of 17:52 UKMO has not updated

[Frosty.]

Now this is more like it, much better than the 6z op in FI with the azores/atlantic high finally able to build in properly, it actually tries this next week but is only partially successful due to that pesky trough to the east, but mid month would be very pleasant with high pressure in charge and temps into the low to mid 20's celsius but cooling off at night with fog in places.

[Methuselah]

This chart from the Gfs 12z reminds me of when moses parted the red sea..but the similarity ends there

That looks like the Triangle, Frosty...

[Summer Sun]

ECM is slower at getting the high in next week this evening

 

 

Whether UKMO has followed is anyone's guess as it still hasn't updated

 

The low to the east is proving troublesome this evening

 

Edited September 5, 2013 by Summer Sun

[draztik]

Following on from the gfs 6z this morning, ECM now suggesting HP reluctant to build, because of the trough to our east. It keeps the weather unsettled in the east and cool nationwide.here are the charts for next Wednesday

Edited September 5, 2013 by draztik

[Summer Sun]

Low pressure remains anchored over Greenland this evening but the low pressure to our east is stopping the high getting in this evening

 

 

GEM makes a better attempt to get the high in though

 

 

Before the low over Iceland forces it south and introduces something cooler

 

 

NAVGEM also tries to get the high in but it too struggles like the other models it also agrees on lows anchored over Greenland

 

Edited September 5, 2013 by Summer Sun

[Man With Beard]

ECM is slower at getting the high in next week this evening

 

 

Whether UKMO has followed is anyone's guess as it still hasn't updated

 

The low to the east is proving troublesome this evening

 

 

Yes recently ECM hasn't been very consistent at all at T120 onwards, this is completely different to last night. Suncream can be moved from the kitchen cupboard to the loft based on this one

Edited September 5, 2013 by rjbw

[Frosty.]

I like the longer term trend from tonight's GEFS 12z mean, high pressure could dominate the period spanning mid september with the PFJ being forced even further north as time goes on, the charts look excellent for a summery pattern as we go deeper into autumn,,BRING IT ON.

[Summer Sun]

The GFS 12z ensembles don't look too bad evening rainfall looks like staying quite low once tomorrows potential deluge in some eastern parts is out the way and the uppers after a cool spell this weekend make a steady recovery through next week and beyond

 

[Frank Trough]

the models seem to be working as a team at the moment. The GFS's cut off low scenario was corrected by the Euros and now the GFS appears to have helped out by suggesting that it might be an idea to keep pressure a bit lower to the east rather than just let high pressure calvary ride back in.

 

I'd be amazed if the UKMO doesn't make more of the low to our east this evening.

 

It might just be a delay, they may have made too much of it.....or it might prove to be enough stalling to prevent high pressure in at all.

[No Balls Like Snow Balls]

I like the longer term trend from tonight's GEFS 12z mean, high pressure could dominate the period spanning mid september with the PFJ being forced even further north as time goes on, the charts look excellent for a summery pattern as we go deeper into autumn,,BRING IT ON.

You been smoking pot bro ?