Time for the latest update,

Please get involved on the dedicated Glastonbury forecast thread on the main forum here

[url="http://forum.netweather.tv/topic/76531-glastonbury-wed-26-to-sun-30-june-2013/page-4#entry2714670"]http://forum.netweather.tv/topic/76531-glastonbury-wed-26-to-sun-30-june-2013/page-4#entry2714670[/url]

Starting off with the [b]GFS Operational Charts [/b][based on 12Hz 15th June run]

I'll bring the days forward to be consistent with the op runs of previous days.

Charts shown in order (168 Sat 22nd June, 288 Tue 25 June, 312 Wed 26 June, 360 Fri 28 June)

The trend has been for High Pressure to slowly build from the South West, but some runs such as the 00Hz operation run today, went against this somewhat.

Looking specifically at the 12Hz op run, in the short term the precipitation forecast for the next 6 days has been reduced, with the majority of the rain over the next 48 hours. 15mm is more than manageable.

[attachment=174462:Rmgfs144sum 15.gif]

The general flow of the weather is for the Azores High Pressure to the far South west, and lower pressure further north, at times low pressure push westward/ South Eastwards over the top of the High pressures. So never settled and a changeable theme. The op run shows the worst of the Low Pressure staying over the north of the UK, as opposed to the 00Hz run which had it much further south for next weekend, so while never staying completely dry over Glastonbury, rainfalls totals not massive.

Into Glastonbury week, Pressure starting to rise significantly from the South West, however a fly in the ointment in that a LP system is forecast over the UK for Thursday and Friday which could give appreciable rainfall.

[attachment=174466:GFS 15 1.JPG] [attachment=174465:GFS 15 2.JPG] [attachment=174464:GFS 15 3.JPG] [attachment=174463:GFS 15 4.JPG]

So very much a mixed picture from GFS today, good news in that it looks drier/less wet over the next couple of days and that the 12Hz keeps Low Pressure largely effecting Northern areas for next week. but bad news in the chance of some unsettled weather for the festival itself, each of today's op GFS runs has had some unsettled weather at times over the festival period.

[b]GFS Ensembles[/b] [based on 06Hz 15th June run]

[attachment=174473:GEFS 15 06 1.png] [attachment=174472:GEFS 15 06 2.png] [attachment=174471:GEFS 15 06 3.png] [attachment=174470:GEFS 15 06 4.png]

Pressure is generally set to rise to over 1020mb by mid the coming week, a brief dip is expected next weekend but back over 1020mb by the start of the festival, before dipping a bit at the end.

Rainfall shows a few peaks, firstly this weekend and to a lesser extent next weekend, apart this not completely dry, but no real wet weather, with the exception of the op run blip towards the end.

These are the most promising ensembles seen for a number of days.

[b]GFS Ensembles[/b] [based on 12Hz 15th June run]

[attachment=174498:GEFS 15 12 1.gif] [attachment=174497:GEFS 15 12 2.gif]

Again this shows Pressure quickly building up from the South West, and more settled than the Operational runs.

The Somerset charts were not available.
[b]NOAA Upper Charts [/b][based on run published 15th June]
Note these are raw charts, these are not modified by forecasters at weekend.

[attachment=174490:610day.03 15.gif] [attachment=174489:814day.03 15.gif]

For the first time in a while the trough has lifted away from the UK, with neutral conditions over the UK at the 8-14 days range.

[b]ECM[/b] [based on 00Hz 15th June run]

Charts shown in order (144 Fri 21 June, 168 Sat 22 June, 240 Tues 25 June)
[attachment=174476:ECM 15a 144.JPG] [attachment=174481:ECM 15a 192.gif] [attachment=174474:ECM `15a 240.JPG]

Generally an unsettled theme, but the worst of the Low Pressure over Northern areas, and not too bad for Glastonbury, however Tuesday (T+240) looks a bit more troublesome as the LP would most likely move across eastwards across southern areas at the start of the festival. In contrast the ECM ensembles has pressure building up slowly from the south west.

[b]ECM[/b] [based on 12Hz 15th June run]

[attachment=174478:ECM 15b 144.gif] [attachment=174484:ECM 15b 192.gif] [attachment=174488:ECM 15b 240.gif]

Again generally an unsettled theme, but the worst of the Low Pressure over Northern areas, however it tends to develop the Low Pressure a little but more for next weekend. A ridge of High Pressure looks likely to follow but with a Low Pressure to the west again looking ominous.

[b]Summary [/b]
A general theme at the moment of High Pressure not far away of the South West of the UK, however how dominant this will be is very much in debate. Low Pressure systems look likely to move Eastwards across northern areas from the middle of next week onwards, southern parts of the the UK should be drier, but some runs today have some shown these Low pressures system on a slightly more southerly track at times, giving a bit more rain for South Western England next weekend and around the start of the Glastonbury festival.
Conversely the ensembles look a bit drier and maintain the theme of pressure rises from the South West.

[b]Starting the ratings :- [/b]

Festival Dryness (0= washout, 5=dry) 5.5/10 an increased risk today of some rain during the festival, but no washout likely.
Ground Mudbath Rating (0=mudbath, 10 = dustbowl) 4.5/10 Today's models show the next 6 days to be drier than previous runs, reducing the risk of a mudbath.
Heatwave rating (0 = freezing, 10 = heatwave), winds from a general western direction, 850HPa temps look around average.

[b]Newspaper Taglines [/b]

Bring your wellies and your sunglasses, the festival itself still possibly drier than average,but pre festival rain could make ground underfoot wet and cause some mud on site, but probably without actually mud bath conditions.