Penellype's Weather Channel

[bikermike]

Hello!

I was just looking at metcheck that seemed to suggest no rain for November for my area just above london. That will make things crazy dry. Are your models suggesting such a dry patch?

[Penellype]

Hello!

I was just looking at metcheck that seemed to suggest no rain for November for my area just above london. That will make things crazy dry. Are your models suggesting such a dry patch?

November? I don't know of any models that can accurately forecast 1 month ahead, let alone 2. You will probably find that this forecast changes from day to day with each run of whatever model it is that they are using. My advice would be to ignore it and wait until nearer the time.

For what its worth (not much), this is what the CFS model is currently showing for November:



IF this were to be correct it would indeed be very dry, but that is a big IF at present. It might look completely different by tomorrow.

[bikermike]

Thanks Penellype!

I was taking it with a pinch of salt, but it's interesting it's not completely off the scale.

The plot is pretty dry now and the longer clay has to dry out, the longer it stays dry when rained on.

[Penellype]

Make the most of today, and tomorrow if you live in the east, as things are about to go downhill, giving some much-needed rain. Next week looks likely to be increasingly wet, windy at times and rather cooler as low pressure moves in from the west. As the moment there is uncertainty about how long this will last, with some models wanting to bring back high pressure while others keep us unsettled and cool into October.

[Penellype]

Warning of heavy rain for much of England and Wales tomorrow as the remains of Hurricane Humberto arrive. there could be flash flooding in places.
https://www.metoffice.gov.uk/weather...ce/uk-warnings

[Penellype]

Lovely illustration of what happens when the centre of a low pressure system passes overhead from the local weather station data:



Temperature (off the top of the screenshot) was roughly level throughout, but the wind direction changed sharply from south to all over the shop as the centre passed overhead. There were 2 distinct bands of heavier rain, the first accompanied by gusty winds and the 2nd heralding the arrival of the low's centre. A very noticeable swirl of torrential rain was visible on the radar, which I forgot to take a screenshot of at the time.

30mm of rain in about 5 hours was enough to flood the bottom corner of my allotment.

[1Bee]

That's fascinating, Penellype, thank you.

[Penellype]

Models are firming up on quite a notable cold snap (for the time of year) next week. Air frost is looking possible in the northern half of the country, with Tuesday night and Wednesday night looking the most likely. Check local forecasts and be prepared to cover things up or pick crops of vulnerable plants before they get damaged.

No real let up in the wet weather either I'm afraid, apart from a brief mainly dry spell accompanying the cold nights.

[Penellype]

Something to watch out for towards the end of the week, especially if you live in Ireland, where things could get nasty. Hurricane Lorenzo, currently in the middle of the Atlantic, is currently forecast to come this way. The latest runs of the GFS and ECMWF models appear to have calmed things down a bit, but the latest forecast from the NOAA hurricane centre in America looks somewhat scary:



Yes, that is a post tropical HURRICANE off the west coast of Ireland on Thursday. I don't ever remember seeing the H in the middle of a circle that far north before, but I may be wrong.

The GFS has Lorenzo further south and a much weaker feature:



Let's hope the GFS is right!

[Penellype]

Update on Lorenzo.

When I posted last night Lorenzo was category 3 (M on the map refers to a major hurricane category 3 or above) and forecast to decrease in strength to category 2 (designated H on the map) by this morning. What has actually happened illustrates just how hard these things are to forecast. Lorenzo is now category 5 (the highest possible) with maximum sustained winds of 160mph. This is the strongest hurricane ever recorded this far north and east in the Atlantic. It is currently moving north and as it reaches cooler water it cannot retain this sort of intensity and will rapidly weaken.

NOAA has not changed the forecast track of Lorenzo, which is projected to be centered somewhere over Ireland by Thursday night as a post tropical storm (max sustained winds around 70mph). While not a hurricane, this would give a battering to a large portion of the UK. The Met Office is roughly in agreement with NOAA. The GFS model wants to keep Lorenzo further west for a while, where it would interact with other low pressure systems, weakening as it does so. The combined low pressure system would then arrive some time over the weekend. The ECMWF still wants to send Lorenzo to the south of us, as it did yesterday.

Regardless of where it ends up, Lorenzo is whipping up a huge swell and a storm surge is extremely likely at some point. If you live near the coast, particularly the south west, be prepared for flood warnings from this later in the week.

Information on the development of Lorenzo (and other tropical storms and hurricanes) can be found here: https://www.nhc.noaa.gov/.

[1Bee]

Well, here comes winter! First time scraping the windscreen, and first school closure due to flooded roads of the season.

Hey ho. Good job I brought in all the chillies yesterday, eh?

[bikermike]

some very soggy manx types over the last day or two. Hope all our three-legged grapes are OK.

It was 4C down our way in tropical north London...

[Penellype]

Warnings now appearing for wind as the models firm up on the path of ex-hurricane Lorenzo, which has been very uncertain until recently. Orange and yellow warnings for the republic of Ireland Thursday into Friday - see https://www.met.ie/warnings. Yellow warnings for parts of the west of the UK https://www.metoffice.gov.uk/weather...ce/uk-warnings.

[bikermike]

unexpected light frost this am. was supposed to be cold yesterday morning, not today...

[Penellype]

Yesterday and today. Today was worse as the wind completely dropped. We were forecast to go down to 3 here, but actually reached 0.1.