Penellype's Weather Channel

[sandspider]

Thank you for the detailed response. I didn't think it would be a simple matter to forecast!

Probably best to assume the worst (I have lots of firewood!) and hope for the best

[Penellype]

Yellow warning of thunderstorms in the east this afternoon and evening as the hot weather breaks down. As always not everywhere will get one but they could bring torrential rain, hail and frequent lightning if you catch one. Keeping an eye on the radar and the sky is a good idea if you are outside as these can develop very quickly.
https://www.metoffice.gov.uk/weather...ate=2019-08-27

[Penellype]

Some quite chilly nights possible this week with a possibility of ground frost in vulnerable areas in the north. Worth keeping an eye on the forecasts and closing greenhouse doors etc if necessary.

[Penellype]

Saturday night is looking particularly cold - we are forecast to drop to 4 here which is almost ground frost territory. Some other parts of the country could well be colder and everywhere away from the coast is likely to drop below 10.

[Chippy Minton]

Ah, the 'F' word. Always hope not to hear that until October time, but it's been a weird year.

Also clicked 'like' to indicate I like the fact, and how, you share the information, not that I like the information! We need another button

[Penellype]

After a very pleasant day today, things go downhill for tomorrow, with an unpleasantly cold, wet day on the cards. Things remain changeable to mid week, with the remains of 2 hurricanes (Dorian and Gabrielle) heading our way. Dorian will pass to the north of Scotland around Wednesday as a fairly standard low pressure, bringing some wind and rain and milder air. Gabrielle moves a little further south, so Thursday could be a bit windier with a band of rain moving south east across the country. Don't believe scare stories that we are about to be battered by hurricanes - they will have lost their strength by the time they reach us.

As Gabrielle clears away it becomes cooler and fresher, but high pressure builds from the west, and at present this looks like sticking around for a while, maybe bringing a taste of summer back in the middle of September. This is a fair way off, and things can change, but the common September pattern of ex-hurricanes changing our weather looks likely to happen again this time.

[Gillykat]

A couple of those fonts of all knowledge (aka the papers ) were today warning of a very bad winter ahead with extreme cold from January onwards. I must admit my first thought was ''Well that's alright - I'll have the allotment weeded, tidy and all sorted by then!''

Entertaining idiots, the lot of 'em!

[Penellype]

A couple of those fonts of all knowledge (aka the papers ) were today warning of a very bad winter ahead with extreme cold from January onwards. I must admit my first thought was ''Well that's alright - I'll have the allotment weeded, tidy and all sorted by then!''

Entertaining idiots, the lot of 'em!

Eventually we will have another cold winter. December 2010 demonstrated that climate change does not necessarily mean that it will not be cold here - it was the 2nd coldest December (by just 0.2 of a degree) in the Central England Temperature record that goes back to 1659. No doubt when that happens the papers will say they told us so, even though they routinely churn out these hyperbolic predictions of snow/cold/armageddon at every conceivable opportunity.

It is not possible to accurately predict the weather beyond about 5 days. There is some merit in 10 day forecasts under some circumstances, which can give you an idea of general trends but are subject to change and can be completely wrong. Anything beyond that falls somewhere between just for fun and complete fantasy as can be demonstrated by the fact that there are often huge differences between consecutive runs of the longer term models.

There are several "pointers" towards a colder winter this year, but that does not necessarily mean it will be cold. The nearest recent year I can find with an increasing easterly QBO, near solar minimum and with a weak la nina signature is 2000 - it is not a particularly good match as it was coming out of solar minimum while we are just entering it now, but there were some similarities in the September sea surface temperatures. 2000 - 2001 was not a particularly cold winter, although March 2001 was on the chilly side.

[1Bee]

It got down to 10 in the growhouse on Sat night, just as you said (if it's 10 in the growhouse, the backyard will be about 7 and outside the yard somewhere around 5, I'd guess).

Which means I need to move the chillies inside and decide which ones I'm going to try and overwinter.

I'm not READY!

[Thelma Sanders]

Pen it seems to me that the effect of the solar minimum is being underestimated considering that Nasa says

The forecast for the next solar cycle says it will be the weakest of the last 200 years. The maximum of this next cycle – measured in terms of sunspot number, a standard measure of solar activity level – could be 30 to 50% lower than the most recent one.

https://www.nasa.gov/feature/ames/so...or-exploration
I think this will make the weather very difficult to predict, compared to modern day 'normal' and quite likely cooler in this part of the world.
What's your take on this?

[Penellype]

Pen it seems to me that the effect of the solar minimum is being underestimated considering that Nasa says https://www.nasa.gov/feature/ames/so...or-exploration
I think this will make the weather very difficult to predict, compared to modern day 'normal' and quite likely cooler in this part of the world.
What's your take on this?

I am not an expert on solar activity and I do not understand anything about how the predictions of solar cycle strength are measured. I leave that to the experts. The article you link to is talking about space weather in relation to the safety of astronauts. A strong solar cycle with high levels of activity produces a lot of cosmic rays and solar particles ejected from the sun's surface during coronal mass ejections (CMEs), which can be hazardous for space craft and satellites. These particles are deflected from earth by its magnetic field, and result in auroras, the strength of which depends on the amount of particles from the CME hitting the earth's atmosphere. As far as I am aware, none of this directly affects the weather on the earth's surface, although a large solar storm has the potential to disrupt electricity supplies and protections are built into the grid to predict and prevent this happening.

As far as the earth's weather is concerned, there is a theory that low solar activity increases the chances of northern blocking (high pressure over the north pole). I do not know the reasoning behind this. If northern blocking occurs and is in the "right" place then this can cause winter in the UK to be cold. The right place in this context is over Greenland (resulting in northerly winds) or northern Scandinavia (resulting in easterly winds). Even if there is northern blocking there is no guarantee that it will be in one of these positions.

Historically there have been previous periods of low solar activity over several solar cycles, notably in the Maunder and Dalton minimums, when the winters here were indisputably colder. There is definitely speculation on forums that we are heading into another Grand Solar Minimum of this type, and we could well be. The difficulty with this is that with the solar cycles being 11 years long on average, and records only going back a few hundred years, there is not enough data to make statistically significant predictions about the effects of weak solar cycles on the weather. There are only 2 solar cycles (5 and 6, during the Dalton Minimum) since numbering started that were notably weaker than the one we have just had (24). The Maunder Minimum, which lasted much longer, occurred in the 1600s and early 1700s when methods of measuring sunspot numbers were different and small sunspot areas may have gone unnoticed.

There is also apparently a link between low solar activity and increased volcanic activity, although I have no idea how that works. Volcanoes throw ash and soot into the upper atmosphere, and severe eruptions can cause a significant cooling effect over the whole planet for several months. This would add to any direct effects of the low solar activity if it happened.

The question that I think nobody can answer is how much of this would be offset by climate change if a Grand Solar Minimum similar to the Maunder Minimum did happen. All else being equal (it never is) the world is set to warm considerably due to greenhouse gases already in the atmosphere, regardless of what we do. We can only attempt to not make it too much worse. The sun may come to our aid for a while, but I do not know what the numbers are in terms of degrees of worldwide cooling from a Grand Solar Minimum. In any case this is talking about worldwide climate, which is a very different question from winter conditions in the UK. Cold UK winters can still occur in a warming world, but personally I would be surprised to see a return of frost fairs on the Thames in the foreseeable future. I could easily be wrong.

[Thelma Sanders]

Yes.
Nasa saying there will be a solar minimum, but giving no clue about weather effects, or any possible cooling, even if it is only temporary
Nor is NOAA other than to say " Space weather and terrestrial weather (the weather we feel at the surface) are influenced by the small changes the Sun undergoes during its solar cycle. " No clues there then..

So you're as much in the dark as me, then, we'll just have to wait to find out, as usual

[Penellype]

Today a cold front is moving south east introducing cooler air to the south behind a band of showery rain. High pressure is set to hold the fort during the week so it will be mainly dry, but as the air mass is cool there could be some chilly nights where skies are clear. Ground frost is not out of the question in vulnerable rural areas.

The tropical Atlantic is looking fairly active at the moment, and tropical storm Humberto, which is expected to become a hurricane tonight, looks as though it may have a significant role to play in our weather next weekend. These things are very hard to forecast, but at present the models have the high pressure breaking down to allow much more unsettled weather (including the remains of Humberto) in around this time next week. This can of course change as there is always a lot of uncertainty where ex-hurricanes are concerned, but if you like the fine weather the advice is to make the most of this week as well as to keep an eye on the forecast night time temperatures.

[Mark_Riga]

This can of course change as there is always a lot of uncertainty where ex-hurricanes are concerned, but if you like the fine weather the advice is to make the most of this week as well as to keep an eye on the forecast night time temperatures.

I find it difficult to find a good forecast for night time temps. The met office only seems to forecast city tempsmeven though I picked a local spot in the country for a forecast. The best site I've found is netweather.tv do you know a better one or is that as good as any?

[Penellype]

I use the high resolution Arpege model, which updates twice a day and gives 1 hour forecasts out to 102 hours. The temperature charts can be found here:
https://www.theweatheroutlook.com/tw...=2m%20temp%20C.

A comparison with the GFS model, which updates 4 times a day and gives 3 hourly forecasts, is useful for a second opinion - the minimum temperature forecasts are available on the left here:
https://www.theweatheroutlook.com/tw...datmdlout.aspx

Remember that like weather app forecasts (and very probably the netweather ones) this is raw model output and has no added human interpretation, unlike tv forecasts. You will learn from experience how your location compares with the figures on the charts - I find the Arpege is often a little lower than the GFS, sometimes several degrees, in which case I am usually somewhere in between. But as always, the forecasts can sometimes be badly wrong, often due to unexpected cloud or lack of it. A clear night will always be colder than a cloudy one.