Model Output Discussion - 1st June 2015 12z--------->

[Nick F]

One thing that im looking forward to most is the possibility of some great thunderstorms, its years since ive seen a 'proper' one.

 

Ive just been having a look on the GFS charts but ive not had much experience with CAPE etc. On Meteociel there is 'CAPE et LI' and 'MUCAPE MULI' and both look similar when running them through but should I be looking at one thing specificaly??

 

If im reading it right then Wednesday evening looks very fun going by this !?

 

 

This a good guide to the different types of CAPE you refer to: http://www.spc.noaa.gov/misc/unstable.html

 

The CAPE charts only tell part of the story though for storm potential, FWIW this far off GFS doesn't really break out much in the way of precip across southern Britain Weds evening, despite the high CAPE/low LI values, certainly surface based storms - because of capping inversion (warm dry layers aloft preventing parcels rising), though it does indicate mid-level precip moving up from the Channel. Of course GFS precip charts not to be relied on too much in storm forecasting situations, in the past they have been unreliable at times with their resolution, so will have to wait and see nearer the time.

 

The Euros so far today showing more amplification of the trough to the west (thus slower breakdown) than both 00z and 06z GFS runs, so remains to be seen IMO how quickly the heat will be removed, certainly from E/SE Britain, by next weekend.

 

Too far off to forecast thunderstorms, though it does look more likely that storms will develop across far western areas to begin with on Wednesday on the W/NW edge of the hot and humid plume - where colder air from the ttrough to the west over-runs, then perhaps more widespread across the UK on Thursday, as per GFS, though ECM still keeps thundery activity running north over the western side of the UK before breaking out storms further east Fri/Sat - because it is more amplified and slower with the breakdown from the west.

 

All-in-all, for once, it will be an interesting weather period to watch/experience for the UK IMO, as these plumes don't come along that often!

[mushymanrob]

I can't see any sign of a second plume on the anomalies into the ext period. The ecm is going for the Azores HP to the SW and a flat W/SW zonality. Quite pleasant all the same.

 

Blast I've just remembered it's Maisie Day in Penance today.

Maybe not a second plume but more heat via building azores and high uppers

[Frosty.]

It wasn't long ago when the models were showing the plume missing the UK to the east by some distance but how things have changed, quite a dramatic turnaround with a full on spanish plume event incoming. The GEFS 6z mean shows this well with increasing heat and humidity +15 plus 850's..564 dam thicknesses pumping northwards across all areas, there is talk of conditions becoming very hot across the south eastern half of England with temps between 30-34c later next week but generally across the rest of Britain we are looking at 26-31c range from north to south.

I regard this upcoming hot spell as a bonus because for a long while it looked like the Atlantic trough would be too close to the UK. It's a great outlook, lots of hot sunshine but with high uv levels, and a growing chance of intense thunderstorms being triggered by the heat, some storms at night too...The further outlook is for the warmest and most settled weather across southern UK with potential reloads of hot weather from the south and the most changeable in the northwest corner but still with fine and warm spells too.

Edited June 27, 2015 by Frosty.

[A.J]

It wasn't long ago when the models were showing the plume missing the UK to the east by some distance but how things have changed, quite a dramatic turnaround with a full on spanish plume event incoming. The GEFS 6z mean shows this well with increasing heat and humidity +15 plus 850's..564 dam thicknesses pumping northwards across all areas, there is talk of conditions becoming very hot across the south eastern half of England with temps between 30-34c later next week but generally across the rest of Britain we are looking at 26-31c range from north to south.

I regard this upcoming hot spell as a bonus because for a long while it looked like the Atlantic trough would be too close to the UK. It's a great outlook, lots of hot sunshine but with high uv levels, and a growing chance of intense thunderstorms being triggered by the heat, some storms at night too...The further outlook is for the warmest and most settled weather across southern UK with potential reloads of hot weather from the south and the most changeable in the northwest corner but still with fine and warm spells too.

Re. The first part of your post Karl...I couldn't agree more, just 5 days ago the thread was full of doom and gloom about another plume miss, and the output was quite bullish with this for at least 48 hours....now look at the output!.... It just goes to show that taking model output at timescales of T192+ as gospel is foolhardy, and more likely to be wrong than right

[Methuselah]

Re. The first part of your post Karl...I couldn't agree more, just 5 days ago the thread was full of doom and gloom about another plume miss, and the output was quite bullish with this for at least 48 hours....now look at the output!.... It just goes to show that taking model output at timescales of T192+ as gospel is foolhardy, and more likely to be wrong than right

As 2012's ECM meltdown has taught us, so we pray!

[bluearmy]

Ukmo is a little East compared to yesterday's 12z run with a less sharp dig of the trough. Not as far as gfs. Suspect Ukmo will again provide the middle ground solution.

[Sainsbo]

GFS 12z definitely likes the idea of a reload!

06z

 

12z

Edited June 27, 2015 by Sainsbo

[Summer Sun]

Can't grumble at what GFS is showing so far plenty of heat and the risk of some thunderstorms

 

 

UKMO also shows the high moving back over us at t144

 

Edited June 27, 2015 by Summer Sun

[mhielte]

Great GFS 12z run so far. The heat pushes east during Thursday as storms break out but then reloads for Friday and Saturday.

[Man With Beard]

UKMO T144 (posted by Summer Sun above) is a new concept again - a small high developing over the UK- would be a very hot Friday and potentially hotter Saturday still. I wonder if it may even have delayed the breakdown to later on Sunday, if we'd got to see the whole run?

Certainly seems a slightly hotter run than GFS (Which was hot enough)

[Daniel*]

I see an upgrade on GFS 12z in parts of East Anglia minima no less than 22*C on Wednesday which is spectacular and daunting - I'll add a few degrees onto these low 30's widespread doesn't happen often.

[Summer Sun]

GEM holds the low further west at t144 like UKMO does

 

 

Further heat builds for Saturday

 

 

Slightly lower 850's for the Sunday but I suspect it will still be very warm maybe still hot in the SE with some thunderstorms

 

Edited June 27, 2015 by Summer Sun

[mhielte]

Temps weren't great today and after a brief plume weds through Sat things will settle down ....yes I know NAO is pressure driven but negative with gh suggests mid to late July wet west to nw....NAO about to go negative along with jma monthly suggesting brief plume then return to warm or near normal but with wet spells..as per cc prognosis...July will not be a heat fest that's for sure

 

That's just guesswork at this stage though. This hot plume sprang up out of nowhere after weeks of average-below average conditions. Impossible to tell what July holds after the upcoming heatwave.

[mhielte]

Not really based on NAO gh conditions and week 2 through 4 based on monthly charts and signals from NAO an jet it suggests west to nw which as I suggested means normal temps with brief warmer interludes...all we can go on?

I'm not criticising your logic at all, I'm sure you read the signals correctly, I'm just saying it's a little premature to be writing July off as a potentially warm/hot month. I concede it isn't likely to be special, but it *could* be.

[Frosty.]

Remember when we were stuck under unseasonably cool north westerly winds for weeks and weeks, especially northwest UK, charts like these were a distant dream but now it's reality. Stonking week or more coming up, turning hot and sultry from the south, becoming very hot in the south east, we will all have long periods of strong hot sunshine and scattered severe thunderstorms, nights look very uncomfortably humid with some areas not dropping below 72F. The ukmo 12z shows the hot spell could extend into week 2.

[Methuselah]

Remember when we were stuck under unseasonably cool north westerly winds for weeks and weeks, especially northwest UK, charts like these were a distant dream but now it's reality. Stonking week or more coming up, turning hot and sultry from the south, becoming very hot in the south east, we will all have long periods of strong hot sunshine and scattered severe thunderstorms, nights look very uncomfortably humid with some areas not dropping below 72F. The ukmo 12z shows the hot spell could extend into week 2.

And, as the horribly long-lived cool spell has just shown us, once a pattern becomes established, it can often take some shifting. As yet, I've never seen a convincing forecast - either by model or by man - for what's going to transpire, 32-days from now...

[summer blizzard]

GFS limits the real heat to Thurs-Sat unfortunately for those heat lovers although Tuesday and Wednesday are warm. We still have a front moving through Wednesday night which looks thundery and then the breakdown front on Sat or Sun..

 

 

[Mapantz]

Temps weren't great today and after a brief plume weds through Sat things will settle down ....yes I know NAO is pressure driven but negative with gh suggests mid to late July wet west to nw....NAO about to go negative along with jma monthly suggesting brief plume then return to warm or near normal but with wet spells..as per cc prognosis...July will not be a heat fest that's for sure

The NAO is already -ve

[A.J]

I forgot that the models dictate the weather.....silly me

[on the coast]

I forgot that the models dictate the weather.....silly me

 

[mhielte]

I forgot that the models dictate the weather.....silly me

 Silly you! 

 

[mushymanrob]

Temps weren't great today and after a brief plume weds through Sat things will settle down ....yes I know NAO is pressure driven but negative with gh suggests mid to late July wet west to nw....NAO about to go negative along with jma monthly suggesting brief plume then return to warm or near normal but with wet spells..as per cc prognosis...July will not be a heat fest that's for sure

Thats an overly negetive spin.. Temps werent great today? Have you been outside? Its been a glorious 22c here in derby in strong sun, fresh air, wonderful! Brief plume? We are under high uppers from tuesday to sunday then again into next week. 6 consecutive days of widespread 25c plus, probably into the low 30's c in some areas. Thats a pretty decent hot spell. Isnt 'warm or near normal' for JULY pretty warm,? Even hot?

But with the expected southwesterly upper flow as predicted by the anoms, we look like getting more rain then weve had over the last several months. And id be surprised if the coming heatwave was the only one we get this summer.. I bet theres the motherload towards the end of the month after an unsettled spell.

[Evening thunder]

Temps weren't great today and after a brief plume weds through Sat things will settle down ....yes I know NAO is pressure driven but negative with gh suggests mid to late July wet west to nw....NAO about to go negative along with jma monthly suggesting brief plume then return to warm or near normal but with wet spells..as per cc prognosis...July will not be a heat fest that's for sure

 

ECM monthly goes for anticyclonic settled July though supported by the Atlantic SST pattern and and the Met are going for warmer than average conditions persisting, supported by the Atlantic SST pattern and the MJO, so not all models/signals go for this cooler/wetter pattern

 

GFS limits the real heat to Thurs-Sat unfortunately for those heat lovers although Tuesday and Wednesday are warm. We still have a front moving through Wednesday night which looks thundery and then the breakdown front on Sat or Sun..

 

 

 

Wednesday is definitely hot on the GFS, more so than Thursday

 

[Frosty.]

I expect normal west nw and near norm temps in July....no extended heatwave.

Not according to the experts, they say generally above average temps, especially further south where it looks very warm at times so I'm not buying a return to the cool west / north westerly dross in july. I think the Azores high will have a strong influence next month, at least across southern Britain.

[knocker]

This evenings GEFS day ten anomaly has the upper low off NW Scotland with the trough orientated SW and the ridge to the east. This means the LP will influence the UK more, particularly the NW half, with depressions able to nip between the low pressure and the Azores HP on the jet.  In the extended period the idea is still to relax the trough although LP still remains in the Iceland area and create a westerly zonal flow with the Azores HP edging it's nose in. Temps returning to normal but little precipitation.

http://www.tropicaltidbits.com/

Edited June 27, 2015 by knocker