[Blog] Glastonbury Festival 2015 24 to 28 June - Forecast No 6

June 15, 2015

This is the 6th forecast blog for Glastonbury 2015.

The 4th blog (Issued 10 June) was mostly positive.

The 5th blog (Issued 13 June) was positive and scored 3 out of 10 on the Dustbowl - Mudbath rating. Things were looking positive.

This forecast will be split into 3 main sources

1. Prognostic Charts at 6-10 day and 8-14 day [from NOAA]

These have both moved from the settled outlook of recent days to something more neutral.

2. Ensemble Forecasts

GFS Pressure Ensembles

These are now very messy with quite a large spread, whereas before there was consensus of things remaining settled until at least the immediate run up to the festival. Now average pressure is set to drop back

Now next week the average pressure remains around 1020mb throughout the festival (with the 06Hz ensembles dropping it further at the start of the festival)

GFS Rainfall Ensembles

Again more uncertainty compared to before with some large spikes, with some ensembles going for moderate rain at times during next week, some staying dry or mostly dry.

GFS Temperature Ensembles

Again more uncertainty of this as well, with the average 850hpa temps closer to 5c than 10c to festival, and rising by the end.

3. Operational Runs from GFS and ECM - as they move into the "more reliable " sub T+240 range.

These initially focus on the Monday before the festival, and the Wednesday, as we move through the week these will forecast the whole of the festival period.

Monday 22nd June

The GFS run mostly go for an unsettled picture, with todays 12hz run showing the most settled conditions. There is a pattern at the moment that the GFS op run are more unsettled than the ensembles.

The ECM runs have moved from a rather settled picture on yesterday 00Hz run to rather more unsettled picture (including yesterday 12Hz run not shown.)

Wednesday 24th June

Each of the past 4 ECM runs for Wednesday has shown something different, form the settled picture on yesterday 00Hz run, rather more unsettled yesterday 12Hz and today 00Hz to in an between picture on tonight's 12h run.

Summary

Good

The Ensembles are not that bad

Perhaps the pattern is settling back down from the change of a few days ago to something not too bad

Even if it does rain a little, the ground should be able to take it.

Bad

There is a continuation of a move away from a settled festival

Some operational runs make for gloomy reading

Overall

It is important not to try to overreact to a few bad runs, the chances of a completely dry festival has receded somewhat in recent days. However providing any unsetled wtaher is transient adn tehre is a mix of conditions, then on site conditions are not likely to be that bad.

There is also a slight trend of it being a little unsettled before the festival and perhaps improving during the festival, but this is a hunch and may well be proven wrong.

So overall, there is more uncertainty than before, but given the current dry conditions, I'll still edge to it being more likely a dust bowl than a mud bath. But still take your wellies just in case.

As such I give this festival a 4.5/10 rating at this time (0dustbowl, 10mudbath)

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