Penellype's Weather Channel

[Chippy Minton]

How Do You Solve a Problem Like Maria?

I remember enjoying meteorology up to university level then meeting Rossby waves and jetstreams and realising it was way too complicated for my small brain....... We shall await the outcome with interest, which whilst unpredictable is also inevitable! Keep up the good work Penellype

[Penellype]

How Do You Solve a Problem Like Maria?

I remember enjoying meteorology up to university level then meeting Rossby waves and jetstreams and realising it was way too complicated for my small brain....... We shall await the outcome with interest, which whilst unpredictable is also inevitable! Keep up the good work Penellype

I think it is way to complicated for everybody at some point! Like you, I enjoyed the easy part, learning to identify the various types of cloud, and the simplified versions of high and low pressures, fronts etc - all very nice. Except reality is much more complicated and someone gave me a book with a more mathematical/physics type approach, talking about things like latent heats and coriolis forces which lost me completely. I decided it was all far too difficult.

I think what got me interested again was November-December 2010. I remember weeding the front garden in glorious warm November sunshine when all the forecasts were saying it was going to snow. I brushed it off as just another scare story, but it wasn't, and the next morning it was 4 inches of snow I was brushing off the car. I was snowed in for nearly a week before I could dig it off the drive faster than it came down. The temperatures dropped to below -10 and my water pipes froze. There were 3ft long icicles hanging off the gutters once the snow started to melt then froze again, and finally my boiler outlet pipe froze just before Christmas. I wanted to know firstly why this was happening and then when it was going to stop so I started looking into it and got more and more interested.

Nowadays we are lucky to have access to various videos and forums with people willing to explain things in ways that are easier to understand than dry textbooks. I've found Gavin Partridge (GavsWeatherVids - UK Weather Forecasts And Latest News) particularly helpful and there are links to all sorts of other useful sites on his webiste.

[Potstubsdustbins]

Pen if you don't mind me saying so, I'll stick to fixing boilers and let you do the weather forecasting because with me it would be a case of ......................Whether..........

[Penellype]

Ensemble charts for York now showing the low pressures winning the battle, with the typical wave pattern associated with the warm and cold sectors of the lows:



Also typical is the dry - wet - dry pattern of the rainfall spikes - the further west you are the earlier the rain arrives, so Ireland and the far south west already have the first of the rain bands.

As always the further away it gets the less certain the timing. The 3rd rain band is associated with hurricanes Maria and Lee and timing is still very uncertain, as is the track of this storm system. It could arrive as early as Saturday night or as late as Monday, and it could still go anywhere from south into Biscay to north over Iceland or any number of possible routes in between. The steep slopes on the temperature graph imply that it will be windy - as a rough rule the steeper the temperature gradient the stronger the wind.

Until the models firm up on where this storm system is actually going, attempting to forecast anything beyond it is pretty pointless.

[Penellype]

Still some uncertainties regarding the incoming storm system which contains at least the remains of hurricane Lee, and possibly also Maria - its hard to tell. The Met Office have issued a yellow warning of wind on Monday, but have cancelled an earlier warning of rain as the worst of this appears to be going to be confined to the north west of Scotland.

Basically the weather is going to be changeable, with the worst of any wind and rain occurring the further north and west you go. It will be very windy on Monday especially in Scotland but also northern England, and behind the low that is bringing the wind there will be a change to cooler weather, clearly visible on the ensemble chart:



Keep an eye on local forecasts for possible ground frost and maybe even air frost in vulnerable places next week.

Things are still very uncertain from about Wednesday with big differences between models and individual runs. My money would be on it remaining basically unsettled as the jet stream is quite strong, but some of the models seem to prefer high pressure. As always, we will see.

[1Bee]

I remember that winter (2010) Penellype. Our drainpipe from the kitchen sink froze solid - 3 foot of downpipe, free-draining, in a sheltered corner of a farmyard. The only access to this pipe was by hopping over our backyard wall, so there's me, in six layers, hopping back and forth over a 5 foot wall with hot water bottles and kettles to defrost the thing... My lovely car got obliterated by an idiot in a BMW who thought he could drive a rear-wheel-drive vehicle round a corner on frozen snow at 40mph. I still have a dodgy knee from that one. We sealed off the spare bedrooms, kept all the curtains drawn and moved an extra oil-fired radiator into the living room. I traveled to work in thermals, and recorded -16 in my office car park.

Fun times... ;-)

[Penellype]

I remember that winter (2010) Penellype. Our drainpipe from the kitchen sink froze solid - 3 foot of downpipe, free-draining, in a sheltered corner of a farmyard. The only access to this pipe was by hopping over our backyard wall, so there's me, in six layers, hopping back and forth over a 5 foot wall with hot water bottles and kettles to defrost the thing... My lovely car got obliterated by an idiot in a BMW who thought he could drive a rear-wheel-drive vehicle round a corner on frozen snow at 40mph. I still have a dodgy knee from that one. We sealed off the spare bedrooms, kept all the curtains drawn and moved an extra oil-fired radiator into the living room. I traveled to work in thermals, and recorded -16 in my office car park.

Fun times... ;-)

My horses live about a mile up a single track road. I remember driving up it day after day on frozen snow as the tyre tracks got deeper and deeper. I could hear the ice scraping the bottom of the car and wondered if it was going to rip the exhaust pipe off. Luckily no damage was done.

[Penellype]

Be prepared for quite a chilly night tonight. Ground frost is possible especially in the north so if you live in a vulnerable area make sure that you close greenhouse doors etc.

[Lumpy]

^^^^It was 0C at 6.45 here this morning and some plants had thin layers of ice on them. Now it is sunny as there is not a cloud in the sky. If it stays like this I think tonight might be a bit colder.

[1Bee]

5C at 8.30am! Suspect there might have been a frost on the plot - will check later.

[burnie]

We must have been close to a frost last night, only 5 degrees in the greenhouse, last few tommies look ok and there's new flowers on 2 of them!!

[Penellype]

^^^^It was 0C at 6.45 here this morning and some plants had thin layers of ice on them. Now it is sunny as there is not a cloud in the sky. If it stays like this I think tonight might be a bit colder.

Contrary as it may seem, it is not likely to be as cold tonight as last night. That is because of a change in wind direction and more cloud associated with fronts moving across the country:



at 6am this morning the wind direction was from the north or north west:



By the same time tomorrow it will be more from the west:



The difference in upper air temperature can be seen from the ensemble charts (for York):



The lines start at midnight last night and you can clearly see the rise in temperature by midnight tonight.

The next few nights should be frost free (unless you live on a Scottish mountain), bigger uncertainties start to appear around 10th October.

[Penellype]

This is what I mean by "bigger uncertainties start to appear around 10th October" - just 24hrs later the ensemble chart for York looks like this:



It could be pleasantly warm by the end of next week if this is right.

[Lumpy]

Thank you Penellype you were spot on.

[Penellype]

Quick summary of what's in store this week.

A general pattern of high pressure to the south ridging through the country and to the east at times. Low pressure never far away to the north west meaning that western areas and particularly western Scotland will be wetter than the south and east.

Surprisingly, given the pattern, most places will have at least some rain, if only light, patchy and drizzly in the south and east, and there will be a fair amount of cloud at times. It will also be breezy much of the time, becoming windy later in the week. Temperatures around average to start with, but mild at night except for Wednesday night which could be quite chilly, then becoming warm for the end of the week before temperatures drop back to average at the start of next week where the uncertainties start to increase:



An interesting point from the above chart illustrates the amount of variation at this time of year. The red average temperature line is gradually decreasing as we move slowly towards winter, but notice what happens at the end of October, with quite a marked dip and rise. This line is simply the average of 30 years of temperature readings on those days, and does not mean that the 23rd is always warmer than the 21st October, but it shows how big the fluctuations in temperature can be at this time of year as lows and ridges of high pressure cross the country - big enough to affect the average of 30 years of data.