damianslaw

Cool uppers moving in now. Current temp 15.3 degrees and feels cool despite good sunny breaks. Chilly night ahead.

Yes - last week really of any last vestige feeling of summer... thankfully it looks very pleasant.

Shap is high, located on a plateau about 1000ft.

Certainly an air frost possible jn prone spots, Shap for instance. Much will depend on cloud cover, but the air will be cold enough. We recorded -3 degrees 23 Sept 2012 under a similiar synoptic.

A rarity in this warm year, a period of below average temps ahead, quite a bit so as well, expected highs 13-15 degrees, and mins 4-8 degree range, take the mean value of 14 and 6 degrees and you have a return of 10 degrees, some 4-5 degrees below average mid Sept mean.

Yes Shap often first air frost contender. It's had a ground frost already.

Late 82 brought a super El Nino, possible reason for the exceptional warmth in USA.. and may have been a factor in the switch around between Jan and Feb.

2018 was quite similiar, not the same depth of cold, apart from end of Feb, but generally it was quite a cold winter in Scotland followed by a wonderful summer.

Could be quite an odd September, mild wet first half, cool dry second half, normally first half associated with dry, and second half wet, with cool only at the end. It's turning into a very different September.

September though is often fine especially first two thirds, a singularity it seems nowadays, October and November are the duller months, especially November. Odd to see the heavy rain in London right now, we've had a fine sunny dry day.

Evidence we are now into mid September and a cooler airmass. Not sure how low temp was this morning. but I had heavy condensation in the window this morning, with no heating on... and even though sunny clear skies current temp only 14.3 degrees.

Please keep this thread alive.. it may well justify some activity this week, especially end of the week. Report any ground or indeed air frost.. i'll be keeping an eye on minima..

Scotland endured a consistently cold period from Christmas Eve through until mid February. As evidenced by the fact a number of lochs began to freeze by early February.

The most temperate feeling the year can give is when high pressure is on the scene second half of September - best conditions for outdoor activities.

Could well be a sandwich type month, one with three layers.. the top thick slice denoting wet and warm, middle dry and cooler, bottom slice.. average and wet possibly might be a thin slice...

Yes the evolution of 12z GFS more akin to after effect of a SSW, high pressure over scandi, then major retrogression to the NW and a jetstream collapsed.. an odd run, suspect an outlier. ECM heading towards an atlantic breakthrough but a slow affair.

Unusually the weather today better further north in the region you went. Apart from a brief showery burst early afternoon it stayed dry. Nice sunshine late afternoon and an evening complete opposite to yesterday, fine and clear and still quite light at 8pm. Current temp 12.7 degrees. A long run of nights single digit minima ahead, could well see our first ground frost by the weekend.

Quite a cool down forecast from mid week on and into next week. Even London looks like it will return means 13-14 degree range, below par for mid Sept, CET zone a degree or so cooler would expect. The first half of Sept 2022 will though go down as one of warmest on record I expect. The slow moving low pressure system to the SW key reason, it maintained very warm tropical air over UK and prevented clear skies which at this time of year begin to have a marked cooling effect on mean values.

The strong heights over west atlantic seaboard correlate with the very high SSTs we have in that region right now.. and does seem therefore very plausible. Conversely we see the long wave trough over eastern atlantic seaboard.. it looks like the jet would be NW- SE aligned squeezed between heights to the SW and NE. This would allow for quite a bit of polar air influence. Whilst not a pattern conducive for signficant or sustained cold, it is also one not conducive for signficant or sustained mild either. Could result in a very changeable variable picture, sometimes mild, sometimes cold, sometimes rain, sometimes snowy, sometimes dry and frosty, sometimes stormy.. a real mix, most of our recent winters have been very homogenous with one type of weather dominating, often the wet mild variety. 17-18 and 20-21 only really varied winters since 12-13.

Yes hitting that point in the year when high pressure aloft doesn't necessarily correlate with notable warmth for the time of year, unless it has very warm uppers mixed in, normally when the source is a more southerly one. This current high has cool origins and the continent albeit very slowly is cooling. The movement of such a high as forecast won't result in a notable increase in temps, but will still bring low 20s I suspect - warm but not exceptionally so. A coolish week ahead overall, most notable factor, chilly minima. Mist likely to be very prevalent.

Could produce battleground snowfall events, tug between cold SE airstream and milder SW airstream.. ideally for cold snow rathee than rain you would want heights stronger near Iceland. The north though could sit on colder side of polar front jet.. cold zonality. All conjecture..

Permanent feature in winter nowadays it seems.

Mellow misty mornings with the dew heavy...

The September customary high pressure spell on the way.. rare not to have a sustained spell of settled weather in the first two thirds of the month nowadays it seems. The upcoming week after tomorrow looks mostly fine. Northern parts will see a bit of weak frontal activity, and possible showers especially in the NE as we pull down cooler air from the north from mid week. By the weekend, the models all show high pressure ridging in, cutting off the cooler air. Not expecting this thread to be busy this week at all, due partly to the quiet nature of synoptics on offer, probably the best type of conditions under current circumstances.

Main feature no azores or euro high on the scene.