Model Output Discussion

[Cheese Rice]

It seems Monday keeps upgrading for areas outside the south east. Initially temperatures forecast at 19.c for Tuesday over Leeds, it has slowly risen each day to 28.c. This is a big improvement for not only this area but the whole of Yorkshire and West Midlands, even southern parts of the North West/North East that looked initially to be plagued by cloud and lower temperatures may reach 26.c.

Widespread 30.c over the south east is very likely with London seeing the highest temperatures.

Outside the south east 30.c is possible over Yorkshire/Lincolnshire/Norfolk.

Edited June 25, 2011 by Cheese Rice

[Slowpoke]

18z is awful. Do not look if you like sun and warmth!

[conor123]

18z is awful. Do not look if you like sun and warmth!

There looks like being plenty of sunshine everyday from Tuesday - Saturday for many at least with just isolated light showers, the outlook is much better than recently at least.

[SP1986]

18z is awful. Do not look if you like sun and warmth!

I don;t buy at all into anything shown in 18z, it reminds me of those runs you have in winter where they -25C 850hPa zones getting into UK.

Night temperatures of 5C and daytime temperature of below 15C but seems a little unlikely for a westerly regime.

[feb1991blizzard]

30c would definately be reached with ECM verification but i would also add that it would still be long odds on that 30c would be recorded somewhere in London with GFS 18z SLP and 850hpa chart verification, i know that it only says 28c max for the SE on monday but the GFS under cooking temps coupled with the fact that there are so many weather stations around now its the law of probability that the 30c barrier would be broken, its not even up for debate IMO, saying that if the 18z GFS verifyed in its entirety, not only would it be a short lived hot spell but the first week of July would be cool and showery as well.

[Jason T]

reminds me of my mother n law..bar the sun and warmth bit

YEP...most pub runs do anyway hope the beer was good.

[shedhead]

Looks rather more promising this evening, especially in the south. OK, not hot from Midweek, but plenty of dry and pleasant weather on offer, so a general improvement.

[Costa Del Fal]

The 18z Operational whilst not an Outlier was very much often right at the bottom end of the ensemble members from the 5th July onwards for the 850hpa temps. The Air pressure was also at the bottom end at times.

Even at face value the operational run isnt that wet and given that its not quite the same as what most of the ensemble members are going for, the outlook seems decent enough.

[snowlover2009]

I don;t buy at all into anything shown in 18z, it reminds me of those runs you have in winter where they -25C 850hPa zones getting into UK.

Night temperatures of 5C and daytime temperature of below 15C but seems a little unlikely for a westerly regime.

I agree, but I never recall any runs in winter showing -25 850s?

[95 Degrees]

It seems Monday keeps upgrading for areas outside the south east. Initially temperatures forecast at 19.c for Tuesday over Leeds, it has slowly risen each day to 28.c. This is a big improvement for not only this area but the whole of Yorkshire and West Midlands, even southern parts of the North West/North East that looked initially to be plagued by cloud and lower temperatures may reach 26.c.

Widespread 30.c over the south east is very likely with London seeing the highest temperatures.

Outside the south east 30.c is possible over Yorkshire/Lincolnshire/Norfolk.

Upgrading too for those outside of London in the SE, Even Brighton could see 30C according to the MO, winds do swing South-Westerly rather than a straight southerly on Monday so that would make sense, and the models don't bad at all tonight, especially for the SE, doesn't look like the Atlantic Domination will have the punch it once did, even for those further north.

ECM suggests a possible prolonged hot spell at the end of the run, but GFS doesn't look so good in saying that, not bad for the next week but not so good afterwards, perhaps the ECM is on to something though.

Edited June 26, 2011 by BrightInBrighton

[feb1991blizzard]

I agree, but I never recall any runs in winter showing -25 850s?

Yes, ive never seen a run that brought the 850hpa temps -25c in to britain, cant even recall a stray ensemble getting into this territory although someone is bound to tell me that its happened. Even when the ground temps were stupidly low in dec, the uppers were warmer than the ground temps.

[mushymanrob]

But the high pressure is predicted before though so surely you should know by now that will vary from run to run, there has been hints in the model output in the recent time of high pressure perhaps coming back into the picture for the end of the week in particular so I would not quite say it will be a few days of high pressure then business as usual but didnt that what people just said a few days regarding this heat snap?

Show things can quickly change for the better but we still got to be wary of course because they can change back to a more unsettled outlook.

not sure what you getting at, of course i know runs will vary, but that ukmo 12z yesterday did hint of a possible return to something hotter...thats what i commented on.

its looking pretty certain now that the azores high will ridge in over us from wednesday onwards, and by next weekend in any strong sunshine temps should also get into the mid 20's in the southeastern half of the country. the northwestern half will always fare worse.

the big question then is what will this ridge do?... build to our east allowing something hot? slight chance. the ecm and gfs out into fi suggest the azh will be close, but always anchored to our southwest .... so no washout, but faily pleasant, average, dry, warm, bright, appears to be the outlook into july. no excessive heatwave, but equally not too cool, or wet... lets hope the mjo doesnt head for phase 1...

[bluearmy]

lets hope the mjo doesnt head for phase 1...

most of the forecasts from yesterdays various model runs want to take it into phase 1. lets hope that it stays weak (as it is now) if its headed there. whilst the line stays within the central circle, there is no MJO wave strength to affect the telecons (as i understand it)

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

[k19]

NMM Going for very high CAPE values tomorrow over London and much of the South east. Even brings the CAPE values in a 'band' like formation moving through northern England at about 8pm too.

Edited June 26, 2011 by K.1000

[Gibby]

UKMO this week shows something of a thundery breakdown tomorrow night and Tuesday as the heat gets pulled away SE followed by a cool and fresh couple of days in association with a NW flow before the Azores high rebuilds towards the end of the week to give southern areas at least further warmth and sunshine by next weekend.

GFS is ditto through the week. Thereafter, the high pressure over the south gives ground as pressure falls from the north for a while introducing the risk of rain to all before pressure builds from the SW once more in FI. GFS ends with a slack pressure gradient and the risk of showers. The weather though the period could best be described as changeable with the best of dry and warmer spells in the south while the north runs the greater risk of staying cooler and wetter.

ECM finally also brings more settled and warmer conditions back from the southwest at the end of the week before relaxing things away south as westerly winds take over in the latter stages of its run with always high pressure to the SW and Low pressure to the North meaning as per GFS the driest and brightest conditions are likely further south in Britain.

Taken overall the three models post pretty standard summer fayre at the moment with occasional Azores ridges nosing into southern Britain in the gaps between Low pressures passing east to our North. The weather would also be fairly normal with a lot of dry, bright weather in the south with temperatures near or at times a little above normal while the north sees more rain or showers at times and normal temperatures at best.

[Thundery wintry showers]

There is a chance of thunderstorms in E and NE England this evening, though not East Anglia and the SE, presumably because high pressure is too close by:

http://www.netweather.tv/gfsimages2/gfs.20110626/00/18/ukstormrisk.png

Hot sunshine for most of England and Wales but cloudy for most of Scotland and Ireland.

Tomorrow will be a similar story but perhaps more cloud in northern England and perhaps hotter in the SE (I don't expect 32C but 27-28C is likely). Again there may be thunderstorms in the east but a bit further south than today:

http://www.netweather.tv/gfsimages2/gfs.20110626/00/42/ukstormrisk.png

Tuesday will see the heat and possible thunder restricted to the far SE (exact distribution is subject to revision though). Otherwise cool and quite bright with a scattering of showers, and this cool bright showery weather will extend to all parts on Wednesday. Thursday and Friday will see shower activity die away and temperatures creep up as high pressure ridges in from the Azores.

The weekend will see low pressure try to make a return, but it's all up in the air. The GFS outputs suggest staying mostly warm and bright with just a scattering of showers.

[TEITS]

T

Tomorrow will be a similar story but perhaps more cloud in northern England and perhaps hotter in the SE (I don't expect 32C but 27-28C is likely). Again there may be thunderstorms in the east but a bit further south than today:

http://www.netweather.tv/gfsimages2/gfs.20110626/00/42/ukstormrisk.png

The NAE is predicting 31C tomorrow and the Met O are predicting 32C.

http://expertcharts.weatheronline.co.uk/daten/proficharts/en/nae/2011/06/26/basis00/ukuk/tmax/11062718_2600.gif

Im expecting tomorrow to start fine for many before a line of showers develop across W parts during the afternoon. These developing into thunderstorms and moving E across E/SE during late evening.

[bluearmy]

naefs and ecm ens show very low spreads out to next weekend meaning that the pattern for the next 6 or seven days is pretty well mailed on. the only question would appear to be the intensity and exact track of the depression running across to the north of the uk next weekend. it may well run across northern scotland. what it does mean is that for the midlands south, i'd be very confident to make plans for your BBQ next fri night/saturday. no sign of any real heat after tomorrow but pleasant enough.

deep fi naefs has the mean atlantic jet strengthening again though the spreads dont seem to pick up on any really defined shortwaves. maybe the timing is a bit stretched at the moment. not keen to make a call beyond next weekend for the time being.

[pinball wizard]

The NAE is predicting 31C tomorrow and the Met O are predicting 32C.

http://expertcharts.weatheronline.co.uk/daten/proficharts/en/nae/2011/06/26/basis00/ukuk/tmax/11062718_2600.gif

Im expecting tomorrow to start fine for many before a line of showers develop across W parts during the afternoon. These developing into thunderstorms and moving E across E/SE during late evening.

I've had a look through the charts too and the 06z GFS suggests you are right, TEITS. Having looked at the convective cloud and ppn charts it seems like homegrown storms breaking out across central and then later on eastern parts of the country from noon onwards before a batch of heavier storms move up from the continent between 2 and 6am tuesday morning.

Edited June 26, 2011 by pinball wizard

[shedhead]

Rather disappointing 06GFS on face value if you are looking for the more settled pattern of next week to extend into early July. Unfortunately the persistent northern block is back in place from about T+168hrs,

squeezing the LP's south across the UK and bringing a return to cool, generally unsettled weather. Again tho this is very much at odds with the 00z ECM, which basically has low pressure dominant over

Greenland post T+192hrs - so have one of the big 2 got it badly wrong, or will we end up with something of a half way house come the early part of next week?

[Rob]

Agreed with the above, looks like we are going straight back into the cooler unsettled pattern for the forseeable future, let's just hope that we get a prolonged settled period later in July.

[damianslaw]

Models painting classic average summer standard fare as we head into July. Weak azores ridging in the south at times with low pressure and trough action always close to our NW shores ensuring the ridging remains weak.

Longer term - doesn't appear the pattern is likely to break, if anything the jet looks like having a renewed burst of energy with heights remaining stubbornly high over Greenland sending the longwave trough across our shores on a more southerly path - a common theme of recent July's.. so nothing to suggest a significant lengthy warm settled spell is on the cards anytime soon - I suspect our best summer weather will occur later in July again what you should expect in an average summer.. indeed summer 2011 could turn out to be a text book summer in terms of synoptics and patterns and their timings..

[Rob]

CFS is showing a nice long settled period of weather end of July into August, could be our chance?

[lukemc]

Agreed with the above, looks like we are going straight back into the cooler unsettled pattern for the forseeable future, let's just hope that we get a prolonged settled period later in July.

What makes you think that the GFS is correct - other models are showing more settled scenarios at the moment and I might expect the GFS 06z to not have much ensemble support?

Luke

[Rob]

What makes you think that the GFS is correct - other models are showing more settled scenarios at the moment and I might expect the GFS 06z to not have much ensemble support?

Luke

What makes you think the others are correct? For a while the UKMO was the odd one out with Tuesday, other models were forecasting an absolute scorcher in the SE on Tuesday, but it turned out the UKMO was right the whole time.