Glidemet

It’s grim out there. Really grim. Tomorrow is going to be quite a contrast!

Wednesday, from the Wash to Isle of Wight east, pretty nice cumulus going to 5,000 ft though it may take some time to form with areas of blue thermals at first, and some areas, around the coasts and parts of Kent, will stay blue in sea air. West of this area (including all of the north), cumulus to 3,500 ft tending to spreadout but prone to cycling, so progress with patience should be possible. Light northeasterly winds.

Thursday blue across much of the east and south, but (hopefully) north and west of the Chilterns, shallow cumulus to 4,500-5,000 ft. Rather windy at height though, 10-15 knots for much of the country but 20 knots in the southwest. Should result in blue streets though.

Friday sees a front tickling the west and quite a breeze ahead of it, but a fair hope of cumulus in the southeast. Saturday currently shows the front sliding off the north and decent day across most of the country, while Sunday looks damper.

Vague review of the weekend
Well, just a note to say sorry that Monday turned out to be rubbish, just like the forecast (rubbish, that is), with sun in the southwest and overcast elsewhere. Sunday looked alright though, as roughly hinted at on Friday. Interclub wasn’t Interscrub, so it must have been good.

Friday wasn’t bad though was it? Some interesting comments along the lines of “better than expected”, “better than forecast” and the like. This makes me think two things: 1. Not everyone reads/heeds this forecast. That’s up to them; 2. More importantly, is a comment such as “Really go for it if you can” enough to emphasise a really good day? The furthest I’ve flown is 85 km downwind in a Ka8, so I’m not in a position to say “it’s a 750 day” or whatever. I only do the weather, not task setting. What I will say is that if you see me write something like “don’t under-set” or similar, it’s because I know that people will be commenting that they under-set later.

Flight of the Day from Friday: Andrew Clusky, for setting a task where one of the TP trigraphs is my name (ooo, but which one?!). There, said I’d be more original. Honourable mentions go to 700 km from Challock (even if they didn’t actually get back), and to Rhod Turner, for an excellent reason for setting a particular task. Someone did 960 km too.

Flight of the Day from Saturday, Paul Fritche, for going really fast in a straight line. One hundred miles an hour for sixty straight miles. Sweet.

Flights of Day from Thursday: Mike Schlotter and Trev Stuart for flying down the Jurassic coast and nipping past Exmouth to over Torbay and into South Hams. Trevor even turned a TP in Cornwall, which is something you don’t see every day. (Yes, my FoDs are basically judged on how many of my favourite places any one pilot flies over. I promise I’ll develop more imaginative criteria in the future!)

Today, Friday, as I write, the satellite pic looks superb. Mk 1 eyeball out the window agrees! Generally a fine cumulus field from Scotland to the south coast, but some sea air intrusion in north Somerset and a nice convergence line along the south coast where the sea breeze is fighting the gradient wind. Hope those who have the chance are enjoying themselves.

Saturday lots of rain in the morning clearing to frequent showers; some local soaring possible, most likely in western areas, in the afternoon. Sunday looks somewhat better as the developing low which brings the active fronts on Saturday clears into the North Sea early on, with perhaps fair cumulus to 4,000 ft locally 5,000 ft in the south. However this may overdevelop, and the north currently looks damp and cloudy (but then recently days which looked like that on forecasts have turned out OK, so do not give up hope up there!). Really the day needs a normal day-before forecast as the detail is still hard to pin down, but I don’t think that’s going to be possible from me.

Monday is still a bit wobbly in the confidence stakes, as a warm front sticking out from the next Atlantic arrival does battle with a weak high over the UK. Probably a bit cloudy in the southwest, but optimistically lets say a good 4-5,000 ft over Wales, 4,000 ft over most of England, but East Anglia gets a bit shut down with sea air coming in on a northerly.

Outlook remains a high pressure cell becoming firmly established bringing good summer weather. Not sure of the soaring potential, but it’s greater than if were looking at sustained westerlies!

Morning.

Today (Thursday), away from the southeast where a quite active occlusion is slowly clearing, rather good. Cumulus to 4,000 ft (edit at 0900: make that at least 5,000 ft, RASP is under-doing expected surface temperatures) everywhere apart from Cumbria (lower/damper), and in the far south and across through Dorset and west, where bases may be higher but more likely to just go blue (but still quite high). There’ll be a fair breeze at height, about 15 knots from the northwest, but really quite a good day.

Friday remains breezy at 15 knots or a touch more from the west, but the cumulus is going to be grand, living at 4,500-5,000 ft over pretty much all of England and Wales from early to late. Really go for it if you can; there doesn’t look much risk of spreadout or over-development.

Saturday is wiped out by cloud cover but at least looks vaguely drier than previous runs. And, looking at current run, Sunday even looks quite good away from the south coast! Given the way the GFS has been flip/flopping (that’s the official term, I kid you not), not a lot can be said with confidence about the day. (Technically speaking, the truth of the day does almost certainly lie within the bounds the GFS has presented over the last few days, but given that the “spread” is so large, an overall story cannot be easily discerned.)

(What’s going on is that a small but quite active low pressure system is going to track through on Saturday and Sunday, but the track, timing, and forecast depth are switching around a lot. That’s not surprising given that there’s not much in the way of thermal (and hence pressure) gradients at this time of year, meaning small changes in what the models see in their analysis of satellite, aircraft, surface obs etc. has a big outcome on the forecast. The low may well pass over southern England on Saturday night, which is about the least-worst outcome.)

Monday is displaying more consistency with a story of cloud and a bit of rain in west, maybe fairly good (top cover risks permitting) in the east. And after that, it’s pretty much a certainty that high pressure will become established bringing warm sunny weather.

Probably not another update until some time tomorrow.

May as well get it out of the way quickly.

This bank holiday weekend it will be mostly raining. Yes, I know what I said in previous forecasts, but it happens. Whereas before it looked like high pressure kept incoming Atlantic fronts just at bay, now they don’t. Low pressure dominates.

So tomorrow (Wednesday) East Anglia should be good for a few hours for 3,500—4,000 ft, but cloudy elsewhere. Thursday looks rather good in the southwest and south Wales. Friday could be pretty useful in most places.

Then the rain comes.

Monday sees a weak northerly flow set up as the high that has dominated our weather for the last few days looses its identity (low fill, highs… deflate?). As such it’s quite hard to pin down where will be good and where will be bad. The northeast will probably be a bit damp with a low spreading cloudbase. The Pennines will likely prevent that air affecting the northwest too much, so I suspect we’ll see cloud bases to 4,000 ft without too much spreadout.

Through the midlands, making slow progress southwards, a weak and shallow cold front marks the boundary of the cooler damper northern air meeting the still-warm south, and so will likely be just spreadout stratocumulus. Just to the south though, roughly south Wales to Suffolk at noon, fair conditions with bases to over 4,000 ft in Wales, but down to 3,000 ft in the east. This zone slowly moves south through the day but the associated cloud bases rise—-6,000 ft is not out of the question in south Wales, while 4,500 ft should be seen around the Dunstable area.

South of this area and down into Kent will be blue until early afternoon when quite high cumulus will appear and go to nigh 5,000 ft as far south as Lasham. Beyond there lower/bluer. Generally blue in the southwest but still thermic.

I don’t think one day has ever taken so long to describe. It’ll probably all turn out to be toss anyway.

Tuesday, generally cloudy with only Kent having a bit of a chance. I haven’t really been monitoring the charts as far ahead as Wednesday but right now they show something of a showery low in the Channel with just cloud to the north. The details of the low will probably change but I doubt the general story will much. Thursday looks positively wet on the rear flank of that low with only the southwest peeking out in sunshine, but confidence is marginal. Friday—-hints of ridging with a bit of a northerly (sounds like Monday!). Weekend (have been monitoring, fair consistency on this) looks reasonably settled, again under a weakly ridged mainly northerly flow.

Tomorrow (Saturday) unfortunately now looks to be blue for much of the south. Given the expected surface temperatures thermals will reach an inversion at about 4,000 ft, but as gliders can’t climb to the very top of thermals due to their inherent sink rate, climbs will generally feel like they’re topping out at around 3-3,5,000 ft. Cirrus cover will be much less tomorrow so that will at least help boost climb strengths compared to today. Sea breezes will get a long way into East Anglia and some way into the north east coast, but the influx of moister air will help provide moisture for cumulus, although the climbs they mark probably won’t work too well. Should also be some sea breeze lines along the south coast, and near western coasts too.

The north and Wales should see much more cumulus with bases to about 4,000 ft, with a fair chance of going up to 5,000 ft in the afternoon—-probably the best areas in the country.

Winds will be light westerlies in the north, slack in the midlands, and about ten knots from the east in the south (the result of having high pressure smack over the country).

Sunday again looks best over Wales and the West Midlands (basically Shobdon/Mynd territory), and not bad in the north either although some showers may kick off on the eastern slopes of the Pennines. The south looks “low and blue” (how I hate typing that). Probably the hottest day of the day so far.

Monday looks a right mixed bag, rather cloudy in the north but possibly quite good from North Wales to London and southwestwards, possibly booming along the sea breeze on the south coast. Tuesday a bit cloudy and touch damp for most.