Nick Silkstone

An image of noctilucent cloud looking northwest above Cranbrook, Devon on the 39 June 2025

A great #noctilucent #cloud display across Europe and the UK tonight (including Devon)

These clouds are above 250,000 FT high (a commercial aircraft flies around 35,000 FT for reference) and are most commonly seen in mid-latitudes in mid-summer.

#meteorology

Oceansat-3 pass of showing the satellite derived surface wind field between the Malay Peninsula and Borneo at 16:30 UTC on the 19 March 2025, with the Infrared image (at the same time) in the background. It shows the circulation (located at 0 degrees north) is very close to becoming closed off and becoming a tropical depression....it might already be at that point. This area will drift north and northeast in the coming days, it will be interesting to see what happens.

Keeping up with the potential tropical depression / storm development between the Malay Peninsula / Borneo.

A satellite derived surface wind field (from 19/16:30 UTC) suggests it's close to being a tropical depression at 0 deg.

Slightly inconclusive on the east side of the circulation for now.

Regardless of development of not, an extreme rainfall event is likely for the southern Malay Peninsula (inc Singapore) in the coming 3-4 days.

The ECWMF EFI for precipitation between Wednesday and Saturday >0.9, and the Shift of Tails (how extreme is the extreme) is >3 (compared to March climate).

Screenshort of the GFS model on Thursday 20 March at 23:00 UTC. Showing a closed 1010hPa isobar around a surface low 1009hPa between the Malay Peninsula and Borneo. This unusual signal at such so latitudes is a consequence of the ambient wind field and the shape of the coastline and topography in the region. Under the right conditions of a cold surge from the northeast, and westerly wind burst associated with the MJO to the south the region the ambient cyclonic vorticity can be enough to allow a compact tropical cyclone to form in this tiny expanse of tropical water (lee than 2 deg from the equator).

The GFS model remains keen on generating a tropical depression between the Malay Peninsula and Borneo at <2 deg of latitude.

This last occurred in 2004 when Vamei reached tropical storm / typhoon strength (disputed), such events are estimated to have a 100-400 year return period.

Interesting to 👀

📌

You're welcome. Most UV level forecasts that you get through websites and apps only assume a constant value of ozone (the climate average), and adjust UV per forecast cloud cover.

But in reality UV can be a little different owing to fluctuations in ozone too.

Forecast column ozone anomaly, showing before average ozone across the UK on Sunday 02/03/25.

Unusually low column ozone and clear skies over the UK again today (Sunday), see ozone anomaly forecast below.

UV levels will be higher than normal for the time off year. I got a little sunburn yesterday, so will take the suncream out today.

Enjoy! ☀️

Such terrible news. 😢

All the best to all NWS / NOAA employees past and present from the other side of the pond. We appreciate all you do.

I got the feeling the scientists were not happy / sure it was the correct route, but the pressure came from elsewhere.

They are still producing the plots, and offered me a weekly email update service (via work), which I've taken them up on.

I gave them feedback about the usefulness of the plots.

I got in touch with BoM about the reduction of information.

Their success at messaging ENSO and IOD typical impacts (in recent decades), meant they were finding that media and people were using the status as both to make a crude seasonal forecast, and the actual seasonal forecast was overlooked.

Thank you @kerriedoodles.bsky.social.

I know they are usually seen at temperatures < -20°C, from ice cloud / fog at the surface. In this case the only <- 20 temps were many km up!

My main regret is having no tripod as it was half an hour into walking the dog when I noticed them. 😄

A diagram showing how light pillars are formed / observed. I've crystals reflect light from a source, back to an observer.

Water Vapour image showing the presence of water vapour in the upper atmosphere. I could see some areas of cirrus were present and occasionally dimmed stars

These are formed when ground based light sources are reflected by ice crystals (in this case in high cloud) between the observer (me) and the light sources (unknown).

Amazing to see, shame I was walking the dog and could only shoot handheld with my phone's camera.

Any thoughts or ideas?

Image of light pillars from Cranbrook, Devon

Image of light pillars from Cranbrook, Devon

It looks like I saw the optical phenomenon of light pillars at 20:00 UTC 29 Jan 2025 in Devon, UK this evening.

Vertical pillars of white light that really stood out in the sky for brightness and dead straightness of the lines.

Fantastic work Bruce, it's great to see the table and the rankings. 👏

Do you think the missing obs were linked to power failure in the event? Even if the stations have backups (so the data is not lost), I know a number of them use the mobile network to transmit data.

This could be the equivalent of a 1987 magnitude event for western parts of Ireland.

But nothing like that for England, Wales and Scotland (where high winds gusts are now common).

A screengrab from FlightRadar24 showing aircraft across the North Atlantic at 12:00 UTC on the 23 January 2025. Almost all of the westbound traffic is forced well north, flying the great circle over southern Greenland to be as fuel efficient as possible. Whereas the eastbound traffic is in the stream enjoying the tailwind back to Europe. Only a few business jets which often fly 10,000 FT higher than commercial airlines, so are able to get above the strongest jet stream winds are braving a westbound crossing around 50 degrees north.

#Meteorology makes such a difference to where aeroplanes fly. ✈️

Here a strong W'ly jet stream across the mid-Atlantic (linked to #StormEowyn) causes all the traffic from Europe going to North America to head well to the north.

Whereas the traffic the other way enjoys a jet assisted ride back! 💨

Agreed, I analyse the majority of the rapid dependers in the North Atlantic as having some Shapiro Keyser characteristics.

I find it a spectrum, some are S-K / Norwegian hybrids, posessing elements of both models at various points in their development.

The next low following Eowyn goes through its main deepening stage in the mid-Atlantic.

So it will be nowhere near as potent when it reaches Ireland at the weekend. But winds likely strong enough to hinder recovery efforts.

Unfortunately the first low pressure is now named Storm Eowyn.

Pretty significant impacts (lots of power outages) look likely for Ireland and parts of the UK.

Thanks Paul for all you've done in recent years.

I enjoyed your forecasts and sorry discussions whenever they were issued, but fully understand the rationale behind the decision.

I think there is a good chance of several named storms (when including Ireland), although still a small chance the worst of all could just about miss to the northwest. 🤞

A map from the GFS weather model showing MSLP and jet stream strength at 00:00 UTC on Sunday 26 January 2025 across the North Atlantic. Three areas of low pressure (a cyclone family) can be seen simultaneously at various phases of their development.

A jet-stream fired up by the current North American coldwave will lead to a phenomenon known as a "Cyclone Family" in the North Atlantic.

Multiple deep low pressure areas develop and take a similar track late January (close to the British Isles)

More info: www.nature.com/articles/s41...

Welcome to Bluesky Helen. I really enjoyed following you on Twitter before I left the platform last year.

Looking forward to seeing your amazing creativity here too!

The area shaded in darker blue / purple in the left hand image, indicates the extent of the very unusual / extreme cold around the nadir of the event on Tuesday 21 January 2025.

ECMWF Ensemble Meteogram for daily maximum and minimum temperatures for Austin, Texas.\ Showing a coldwave from Sunday 19 January to Thursday 23 January with temperatures often 15-20 C below average during this time.

A #coldwave is forecast for the central US from the weekend into the middle of next week.

Extending all the way to the Gulf of Mexico and northeastern Mexico.

ECMWF forecasts suggest maximum temperatures for Austin, Texas, may be more than 20 C (36 F) below normal early next week.

That you Celia. I loved it, felt like a day trip to another world, such was the contrast from my muddy neighborhood!

Thank you. It was beautiful, but very cold with quite a wind on the top (even drifting snow).

Full winter gear, gloves and buff required!

For sure, we probably are slightly worse than you on daylight hours ... 08:15am for the sunrise today!

What bike do you ride?

I love all the seasons, although our seasons are much more damped than Canadian ones.

3 days of snow on the ground across the whole season is exceptionally snowy for lower areas of SW England. 😄