17th June update - Glastonbury weather Looking pretty decent this year
17th June 2017
Festival Run Up
High Pressure building over the UK this weekend, this lasting into next week, and only slowly weakening before Wednesday, so a settled and dry run-up to the festival seemingly likely.
After the gates open
Wednesday 21st June – High Pressure is forecast to be centred High over Northern or North Eastern parts of the UK, so probably a settled day, with winds from the South East, some sunshine expected temps 24-26c. Any lower pressure to the west should be kept at bay. Very good agreement on this from the models, GFS and ECM.
Thursday 22st June – High Pressure is set to weaken as a front edges in from the west, with Westerly winds following on behind. This is currently suggested to bring some very patchy rain for the South West, with the morning currently the most likely with totals rainfall totals very small. Into the afternoon, it should brighten up with temps rising to 26-29c, so a very warm or hot day currently expected.
Friday 23rd June – The westerly theme is set to continue, with lower pressure to the North of the UK and higher pressure to the South of the UK. At this stage, Friday looks like being a dry and bright day for Southern parts of the UK. Another warm day, currently suggested to not quite as warm as recent days, with temps 22-25c, as a slightly cooler air mass edges in from the Atlantic.
Saturday 24th June – A similar weather pattern to Friday as the westerly theme is set to continue, with lower pressure to the North / North East of the UK and higher pressure to the South of the UK. There is a risk of Lower pressure edging a bit further South (moreso on the ECM model), so while at this stage, Saturday looks mostly dry, there is greater risk of rain on the Saturday than on Friday. Temps are set to be in the range 20-25c, so another warm day likely.
Sunday 25th June – More in the way of model disagreement, as per previous days, there is low pressure to the North of the UK, some of the models suggest this edging a bit further south on the Sunday, again with the chance of some rain, however at this stage it again looks light and patchy. Temps in the high teens or low 20s.
Three of the 4 GFS runs have total rainfall 1-3mm the other 6-8mm, the majority of this falling early Thursday.
Pressure is set to drop from 1020mb at the start of the festival, to around 1015mb for most of the festival.
The ensembles for the most part are pretty dry, with not that much in the way of rain expected for the festival.
The 850Hpa charts show a decent agreement of 15c for the Wednesday to Thursday before dropping back to closer to 10c over the weekend (Low 20s)
What could go wrong
At this moment, the forecast looks pretty decent, the worst case scenario could be for the low pressure to develop more extensively than currently projected, and turn the weekend wetter than currently projected, but this is not currently forecasted.
Currently looking dry and mostly settled at the start of the festival. As a result ground conditions are expected to be dry when the gates open, with some sunny conditions and temps low to mid 20s.
While a westerly flow seems likely from around Thursday onwards Pressure is always expected to be higher to the South, so while some fronts may edge in at times, rainfall amounts are generally expected to be small.
Temps may drop a little over the weekend but low 20s are still possible.
Mud bath 0 Dustbowl 10
Start of Festival 8.5 dropping to a 7.
While there may be a little rain at times it is set to be mostly dry, and given the current dry warm conditions, it should not cause too many problems.
But it is Glastonbury so always take your wellies, but this year take your sun cream as well.