Penellype's Weather Channel

[Lumpy]

Last nights local news said 83mm in 24 hours. It’s hooted down for the last 36 hours with more coming in.
Rice anyone.

[Penellype]

so whats the outlook for the rest of summer? it going to be another 2012?

A repeat of 2012 is certainly possible, although all years are different. All long range models are experimental and long range predictions are little better than guesses. Here is my guess:

Remainder of June - changeable. Some warmer and drier periods possible but likely to be short, along the lines of a couple of hot days then a thunderstorm. The reasoning behind this is that at the moment an omega block has set up over Greenland:



This pattern of a big high pressure with lows either side to the south is notoriously difficult to shift - last summer's dry weather was the result of an omega block with us under the high pressure part of the pattern. Therefore, although things move around a bit, we are basically likely to remain under the influence of low pressure for a while. Hopefully after the next couple of days it will be more normal changeable weather rather than repeated bouts of torrential rain.

July - most of the models are going for a high pressure dominated July. (They were going for a high pressure dominated June half way through May...). I'm not convinced, although there are signs within the models that a change to higher pressure might be a possibility towards the end of June. If forced to predict, I would go for a mainly changeable July with possibly a week or so of more summer like weather, maybe in the middle of the month.

August - often a dreadful month weather wise. The arctic summer has finished and the temperature difference between the arctic and the equator increases, ramping up the jet stream. This tends to bring low pressures in from the atlantic. However, if the blocked pattern we currently have persists, this might restrain the lows to our west and could give us a drier month, although unlikely to be completely dry. Many of the forecasters have gone for a "back loaded" summer, with the best weather at the end, and this is a possibility. I really don't know.

[Perko]

A repeat of 2012 is certainly possible, although all years are different. All long range models are experimental and long range predictions are little better than guesses. Here is my guess:

Remainder of June - changeable. Some warmer and drier periods possible but likely to be short, along the lines of a couple of hot days then a thunderstorm. The reasoning behind this is that at the moment an omega block has set up over Greenland:

[ATTACH=CONFIG]87329[/ATTACH]

This pattern of a big high pressure with lows either side to the south is notoriously difficult to shift - last summer's dry weather was the result of an omega block with us under the high pressure part of the pattern. Therefore, although things move around a bit, we are basically likely to remain under the influence of low pressure for a while. Hopefully after the next couple of days it will be more normal changeable weather rather than repeated bouts of torrential rain.

July - most of the models are going for a high pressure dominated July. (They were going for a high pressure dominated June half way through May...). I'm not convinced, although there are signs within the models that a change to higher pressure might be a possibility towards the end of June. If forced to predict, I would go for a mainly changeable July with possibly a week or so of more summer like weather, maybe in the middle of the month.

August - often a dreadful month weather wise. The arctic summer has finished and the temperature difference between the arctic and the equator increases, ramping up the jet stream. This tends to bring low pressures in from the atlantic. However, if the blocked pattern we currently have persists, this might restrain the lows to our west and could give us a drier month, although unlikely to be completely dry. Many of the forecasters have gone for a "back loaded" summer, with the best weather at the end, and this is a possibility. I really don't know.

Your knowledge of weather systems is truly impressive!!! I’m not gonna bother with checking the iPhone in the mornings, I’ll look here instead ha!

[Perko]

My central heating kicked in last night. Its set to 10 degrees... in the house... in June. Enough said.

Our heating has been kicking in the last few days too. Very sad state of affairs compared to last year! I checked back to photos I took this week last year and it’s a very depressing picture haha!! I’m just hoping my chillis, peppers and toms are willing to sit it out cos they’re all caked in flowers. Will be really disappointed if they all start dropping flowers

[Gillykat]

It's been raining heavy since around 1am this morning!!! At times during the day we had horizontal drizzle coming down in visible sheets and when I nipped out to the shops at 4pm the rain had briefly stopped but it was so muggy and foggy!

Currently 11.38pm and it is HAMMERING down outside Tomorrow is forecast much the same so as I got all the housework done today (surveyor from housing association coming at 10am tomorrow) I plan to spend tomorrow writing letters and relaxing

[Penellype]

Your knowledge of weather systems is truly impressive!!! I’m not gonna bother with checking the iPhone in the mornings, I’ll look here instead ha!

Please bear in mind that I am an untrained amateur with an interest in the weather because it seriously affects my hobby. I've learned everything I know from sources on the internet (a background in science admittedly helps), quite a bit (but not all) from the very informative daily videos on https://www.gavsweathervids.com/. If you want to know what the weather is likely to do beyond the current day, his videos are probably a better place to start than a weather app, although the forecast videos don't usually appear until after lunch.

[bikermike]

Please bear in mind that I am an untrained amateur with an interest in the weather because it seriously affects my hobby. I've learned everything I know from sources on the internet (a background in science admittedly helps), quite a bit (but not all) from the very informative daily videos on https://www.gavsweathervids.com/. If you want to know what the weather is likely to do beyond the current day, his videos are probably a better place to start than a weather app, although the forecast videos don't usually appear until after lunch.

I think you are being unduly modest about your efforts Penners.

What I find interesting is that you explain it very well.
One of the curses of the internet is that it drives simple pictograms for answers, what these are appalling at is conveying uncertainty. AIUI, british weather is chaotic (ie incapable of definitive prediction) as it is on the unstable boundary between two changeable weather blocs (Continental Europe and The Atlantic). The interrelation of what those two systems are doing, how they interact at the boundary, and where the boundary is, drives our weather.

So if the BBC/whoever put a rain symbol up, it doesn't mean it's going to rain, it means that is the most apposite probable simplification of what the weather in the area so marked is likely too be doing.

If you want to know what is really likely to happen, you need to know what is likely to happen where you are, what is likely to happen in each direction, and how likely those nearby weathers are going to come in your direction. So a proper systemic review is extremely helpful.

As a bike-racer, IoM marshall and gardener, I have spent a lot of time looking at the sky and trying to work out what it's going to do...

[Penellype]

I think you are being unduly modest about your efforts Penners.

What I find interesting is that you explain it very well.
One of the curses of the internet is that it drives simple pictograms for answers, what these are appalling at is conveying uncertainty. AIUI, british weather is chaotic (ie incapable of definitive prediction) as it is on the unstable boundary between two changeable weather blocs (Continental Europe and The Atlantic). The interrelation of what those two systems are doing, how they interact at the boundary, and where the boundary is, drives our weather.

So if the BBC/whoever put a rain symbol up, it doesn't mean it's going to rain, it means that is the most apposite probable simplification of what the weather in the area so marked is likely too be doing.

If you want to know what is really likely to happen, you need to know what is likely to happen where you are, what is likely to happen in each direction, and how likely those nearby weathers are going to come in your direction. So a proper systemic review is extremely helpful.

As a bike-racer, IoM marshall and gardener, I have spent a lot of time looking at the sky and trying to work out what it's going to do...

Above all else, for immediate forecasts, the sky is the best indicator, although you do need to know how to identify the different types of clouds and what they mean. The radar is also a good (but far from perfect) indication of what is likely to happen next.

[Penellype]

Utterly bizarre run from the GFS model today - expect the papers to jump on this and print sensational stories about killer heat. It shows the 25C isotherm at 850hpa encroaching on southern England, with the 20C isotherm through much of England. IF it was right this could bring record breaking heat for the time of year.

However, looking at the ensemble chart, the thick green like shows that the operational run was the hottest:



There is almost no support for this extreme heat from other ensemble members, although some are around the 15C mark. There is no support at all for it from other models and the mid day run operational is much cooler.

Therefore treat any sensational headlines as clickbait and don't pay any attention to them!

[Nicos]

I think maybe we got that here today? 22C most of the day followed by the bestest thunderstorms of the year this evening!
Hailstones the size of gooseberries...
Now dropped to 15C and total calm.

[Penellype]

I think maybe we got that here today? 22C most of the day followed by the bestest thunderstorms of the year this evening!
Hailstones the size of gooseberries...
Now dropped to 15C and total calm.

No, it would be much hotter than 22 if that scenario came off. If the upper air temperature reaches 25 the surface temperature will be somewhere in the mid 30s, depending slightly on the time of year and how much sunshine there is. In August sunshine it would be getting on for 40, a bit less hot in June as the ground hasn't heated up that much yet. The thunderstorms show how unstable the whole thing is - if that GFS run is correct there would be some very thundery weather as low pressure moved into the hot air (which is what is happening on a smaller scale over the south east of England and parts of France last night and today). The storms tend to form in a line between the hot air and the cooler air.

[Penellype]

After a few rather less extreme runs, the GFS is at it again today, with the 25C isotherm even further north than last time:



Other models are hot, but only to the extent of the 20C isotherm grazing the south east corner.

Before you get too excited, this warm spell is likely to be very humid and unstable with showers and likely thunderstorms, probably more widespread than recently. Extremes like this are rarely particularly pleasant.

[Chippy Minton]

Carol Kirkwood was quoting 30C daytime and 19C night time temperatures for the SE next week on this morning's forecats from a windy Ascot. The pumpkins and outdoor tomatoes are hoping it extends to this neck of the woods.

[Penellype]

Thunderstorm warnings over much of the UK in the next few days https://www.metoffice.gov.uk/weather...ate=2019-06-23. There is huge difficulty with forecasting when and where these storms will happen, and weather apps will get it wrong. Here is an example:

York:
Met Office has a front sitting slap over the top of York from tonight into Tuesday. They don't give an accumulated rainfall total but it is likely to be large or very large.
Arpege is similar, forecasting about 50-60mm rain divided about equally between Monday and Tuesday.
ECMWF has the main core of the rain a little further north, with York getting about 25mm over the 2 days.
ICON model has the wettest band further south, with York getting about 40mm over the 2 days.
GFS map only does 5 or 10 days - the total for 5 days appears to be around 30mm here.
The weather app I use, based on the GFS model, shows 9mm of rain, about half of it on Monday evening.
The more "accurate", hourly app (model unknown) shows a total of about 1mm of rain spread out in 0.1 and 0.2mm bursts over the 2 days.

So is it 60mm or 1mm? Should I water in my nematodes or are they going to get washed away in a flood? I haven't a clue.

The best I can suggest is keep an eye on the radar and remember that storms can build very quickly in this sort of unstable air, so if the sun comes out keep an eye on the sky, because it could be raining hard and thundering before anything appears nearby on the radar. Hail and gusty winds are an additional hazard and whether you have storms or not it will be disgustingly hot and humid. There won't be much wind, so if you get a big storm it may hang around for some time.

After the next couple of days it might dry out a bit, although storms are still possible and could still be slow moving and torrential. By next weekend the whole thing is likely to be horribly explosive and cooler air will probably move in at some point around the start of the following week, setting off more storms as it does so. When, and what happens next is up for grabs, but a hot, sticky and at times thundery week is coming up.

[Nicos]

Thanks Pen.
Decision made....going to get on with the gardening today