Penellype's Weather Channel 2

[sandspider]

Thank you, I appreciate the thoughts. We'll find out, I suppose! I wouldn't worry too much, but I need to paint the house and would prefer dry weather!

[Bren In Pots]

Thanks for your explanation Pen, it must be getting difficult I've noticed weather site forecasts aren't as accurate as they used to be.

[Plot70]

There are a couple of things that have been ignored in the official forecasting community.
The most visible effect has been a lack of air craft trails over the past year or so. This causes the solar heat to bake the soil and dry leaf litter to a greater depth increasing the fire risk.
We have seen overheated seedlings this year.
Later in the season we get dirty rain from the forest fire smoke just when we want the sun to ripen our fruit.
Freight aircraft do not leave con trails when they have long landing slots ahead of them. The operators save fuel by gliding them in from 1000 miles distant from there destinations with the engines at idle until they give them a little puff of reverse thrust on the runway to bring them to a halt.

[quanglewangle]

We really noticed the fall off in airtraffic over us then the build up again. The is some sort of NAVAID up the road and we get transatlantic flights coasting in and out as well as transpolar flights from Pacific heading for continent.
This morning about 07:30Z

[Snoop Puss]

We've decided that at the moment, weather forecasts looking ahead more than three days can't be relied on. We've had extreme weather recently and we're now swinging between extremely hot and quite cool weather for the time of year.

[Penellype]

A few rather chilly nights coming up, with temperatures in low single figures for some. If you are in a frost prone area keep an eye on forecast temperatures and be prepared to close greenhouses and cover vulnerable plants.

[sandspider]

Looks like we're in for a hotter and sunnier week next week.

[Penellype]

Looks like we're in for a hotter and sunnier week next week.

Possibly, but not quite a "done deal" yet. The operational run of the GFS model was very hot indeed this morning, but has backed off a little in later runs. There is very hot air over Spain, which will move north into France, but the position of the high pressure will be crucial in determining how hot we get here. To be really hot here, the high needs to be just to our east.

[Penellype]

Temperatures going from the sublime to the ridiculous with the next couple of nights likely to be in single figures, and in some places as low as 3 or 4. If you are in an area that is prone to frost, it might be worth being prepared to cover up vulnerable plants, shut greenhouse doors etc.

[Mr Bones]

Thanks for the heads-up Pen, much appreciated.

[Nicos]

Oh good grief Pen Thanks for the very important heads up.

[Penellype]

After a "cooler" period that we are in at the moment (actually not that far below what used to be summer average for the UK), the GFS model is starting to throw out some extraordinary runs for mid July. This is a long way into the future and as such is unlikely to happen, but this chart for 18th July, from last night's GFS run, is the 4th run in a row where one of the ensemble members shows 40C or more in the south. The current UK record is 38.7C. Weathermen are describing the fact that these charts are appearing at all as "historic".



Bear in mind also that typically for the GFS charts, you can add a couple of degrees to the forecast temperatures.

I hope it is wrong - this isn't a nice warm heatwave, the UK is not set up to cope with these sorts of temperatures and it is a potential killer. For this to be showing up in what "should" be a cool La Nina summer is terrifying.

[Penellype]

For a bit of context, the chart in the above post relates to the thick green line on the graph below (the operational run, which is the highest resolution and therefore supposedly the most accurate).



As you can see, all of the other members of the ensemble are cooler. However this morning's ensemble graph shows something similar, just a few days later:



The huge spread between the hottest and coolest runs shows the degree of uncertainty, meaning that this is most unlikely to actually happen. The worrying thing is that the model is consistently saying that it might.

[Plot70]

Have a look at the Daily Express.
If they forecast it we will have a damp squib

[Jungle Jane]

It will hit 40 degrees here one day,hasn’t been far off in recent years. It would probably be a one day 40 degrees,next day 30 degrees,to get us used to it slowly,don’t worry. Makes me feel a need to mulch,plants stop growing at that temperature & will abort fruit/flowers but then carry on growing when they’re in a comfortable temperature. Pollinators have a few days off,it’s happened before here when it’s been in the thirty something degrees. Doesn’t last long though,in the future it would be for longer but then what will other countries temperatures be,that’s a worrying thought.