Blessed Weather

Quite some squall line passing thru atm. Horizontal heavy rain and hail in the very gusty wind. 09.55

March 2024 Overall for the Region a warmer and duller month compared with the long-term (1991-2020) average. Nevertheless, within that there was a mix of colder, frosty days to start the month, some pleasantly warm weather around the 20th, and even a few thunderstorms thrown in at various times. There was a real north/south split across the Region with regard rainfall amounts, with parts of Norfolk seeing only 50% of normal rainfall as rainbands fizzled out moving north, whilst parts of Kent and Surrey experienced more than double the normal average. UK extremes during the month were: Coldest: Benson, Oxfordshire, -4.6C on the 3rd. Warmest: Charlwood, Surrey, 18.8C on the 20th. Windiest: Needles, IoW, 81mph on the 1st and 28th. Zooming in on East Anglia stats: 4th warmest March on record (+1.8°C) Slightly wetter than average (111%) Duller than average (82%) This is the 2nd warmest start to the year on record (behind 1990, data back to 1884). Chart and EA stats courtesy of Dan Holley, Weatherquest. X @danholley_

carinthian Hi carinthian, I hope you're well. Yes, the Copernicus Climate Change Service report confirms that Europe has been mild this winter, and guess what? Yep, the Alps suffered the biggest anomaly versus the longer term average: "During the boreal winter of 2023/2024, there was a striking contrast across Europe. Above-average temperatures occurred over most of the continent, with the largest anomalies over the Alps and in southeast Europe." Source: https://climate.copernicus.eu/surface-air-temperature-february-2024 I was lucky to go skiing to the French Alps twice over the season and can confirm that pistes below around 1,800m have been frequently impacted by milder spells and periods of rain. Lots of snow to be had higher up, but as you say, the pisting teams have done a great job over the season keeping lower pistes open. Unfortunately the future looks bleak for lower level resorts, which is a great shame as it's the lower resorts that are usually the prettiest, with their beautiful buildings and delightful skiing through the trees.

Wow! And there were skiers on some of those chairs! Cervinia, Italy, on the 30th March. What a nightmare.

Enjoying lovely weather here in Val Cenis, French Alps. Typical Spring conditions with the best skiing in the morning but very slushy on lower slopes by the afternoon. There's a suitable approach to the conditions - get on the slopes early for a long morning's skiing and then sit on the restaurant terrace enjoying a long lunch and beers in the sun. View up to the end of the valley where in the summer you can drive up and over the col into Val D'Isere: Lots of snow at the top: La Fema restaurant terrace, lunchtime today:

Regional stats for February 2024 just posted over in the Records & Stats thread. All in all a remarkable month with records tumbling.

February 2024 It doesn't come as any surprise to see the stats for February 2024 which confirm the month was thoroughly wet, often mild (e.g. see previous post with Santon Downham reaching 18C on the 15th), and with below average sunshine amounts. All in all a notable month with several records for the Region broken. Met Office anomaly charts: For East Anglia it was the wettest and mildest February on record whilst for the SE & Central England it was the mildest and 2nd wettest on record. Furthermore, for East Anglia it was also the wettest October to February period on record and the 2nd warmest winter on record. Whilst most locations across the Region saw over 100mm (4 inches) of rain during the month, there were many locations in the southern counties, namely Hampshire, W & E Sussex and Kent, that recorded over 200mm (8 inches) of rain. Wettest official station was at Plumpton, East Sussex, at 283mm (over 11 inches). Sources: Met Office: https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-actual-and-anomaly-maps Dan Holley, Weatherquest, X @danholley_ Dan Harris, Roost Weather, X @RoostWeather

Please folks - I've just had two mugs of morning tea whilst editing and/or removing posts that were clearly breaking forum guidelines and had been reported. This topic has the potential to bring about strong opinions on either side of the climate change argument; if the thread is going to work we need to keep discussions respectful and free of personal digs please. Thanks.

John Stevens Lovely pics John, thanks for sharing. Looks like a gem of a resort.

Dreadful morning. Our Region is somewhere underneath that lot on the radar at 07.05 this morning. The three triangles show where Hastings (South coast), Hadleigh (Suffolk) and Sea Palling (Norfolk coast) are located. Some of this morning's hi-res models have upped the rainfall amounts before this lot clears later today to around 25 mm (an inch). No sign of a decent dry spell to let the saturated ground dry out; lots more rain later this coming week. 07.05 Arpege accum

Mike Poole Cheshire Freeze Thanks both - excellent summaries of events through December and into January. Imho Cheshire Freeze captures the essence of why the winter of 2023/24 will be remembered as one which promised much but failed to deliver: "I believe that had a decent split of the SPV occurred, we’d have locked in to a blocked regime that benefited the UK in terms of cold, aided by the MJO. I honestly believe it would have been a noteworthy spell." Sadly this sort of let-down allows some to question the value of teleconnections. But hey ho, onwards and upwards - the scientific community is steadily moving forward with research and analysis and every year we better understand how multiple teleconnections, all in various stages of waxing and waning, interact with each other. Forgetting what happened down here on the ground, it's been a very interesting season for events up in the stratosphere, with Canadian Warming, minor SSW, major SSW and (in 2 days time) a second major SSW. Atmospheric scientist Dr Amy Butler rightfully excited by the prospect of 2 major SSW events in back-to-back months: "Pretty psyched about the possibility of a double #SSW year! Last one was in 2010 though the situation was a bit different because one was in late March and barely qualified. Other double #SSW years were 98/99, 87/88, 70/71, and 65/66. Fingers crossed it pans out this year!" https://x.com/DrAHButler/status/1755649856985567435?s=20

bluearmy Apologies for being pedantic, but strictly speaking any SSW in March (assuming it's not the final warming) would be technical reversal number three. The SSW on the 4th Jan was a minor warming, i.e. no technical reversal of zonal winds at 10 hPa 60N. There was a full technical reversal on the 17th Jan and we're on course for the second technical reversal in a couple of days time. More info in the latest NOAA blog co written by Laura Ciasto and Dr Amy Butler: A polar vortex double header The majority of the forecast models say yes, the polar vortex winds will briefly reverse direction within the next week or so, commencing the second major sudden stratospheric warming in as many months. https://www.climate.gov/news-features/blogs/polar-vortex/polar-vortex-double-header

@Mike Poole @Met4Cast As raised in the Model thread, if you wouldn't mind I'd like to discuss with you whether the first Canadian minor SSW warming was of benefit or hindrance to getting cold into the UK back in January. I've started by copying my post of the other day in which Dr. Amy Butler co-wrote a NOAA blog on the 16th Jan. There's a clear pointer in there that the minor warming may have contributed to a Greenland High over the previous week (to the 16th) and would likely have primed the sPV for a further fall later in the month (which subsequently happened around the 17th). Just look at the juicy charts that GFS and ECM were churning out at the time the minor warming was taking place on the 3rd Jan. These forecasts for the 13th Jan: Next these series of tweets by Dr Simon Lee, highly respected atmospheric scientist, all made on the 4th January. He seemed quite clear that the minor warming was behind the forecasts for a negative NAM (AO). I won't copy the full tweet as I hate the way they make loading the Netweather pages jump all over the place. So instead the link is underneath: The temperature of part of the Arctic stratosphere at 10hPa/30km has rapidly risen to +2°C... that's some 60°C above normal! As zonal winds at 60°N won't reverse, this is a "minor warming", but it is still an example of one of the atmosphere's most dramatic natural phenomena. https://x.com/SimonLeeWx/status/1742830496998908272?s=20 The minor warming leads to a negative Northern Annular Mode (aka Arctic Oscillation), which -- combined with the absence of any preceding +NAM, especially in the lower-stratosphere -- looks likely to couple to the troposphere, typically fostering Greenland blocking-type regimes. https://x.com/SimonLeeWx/status/1742830501696593963?s=20 Greenland Blocking-type regimes, favoured when the vortex is weak, drive colder conditions over northwest Europe, and to a slightly lesser extent over parts of the US & Canada. Exceptionally warm conditions also occur in the Labrador Sea & western Greenland, as in this forecast: https://x.com/SimonLeeWx/status/1742830503940530413?s=20 Although the major SSW expected from a few ECMWF forecasts [https://x.com/SimonLeeWx/status/1739751236318920866?s=20] has not verified, this is a pretty decent minor warming (and better than nothing, if this is the sort of thing you enjoy!). It's taken the power out of the vortex right in the middle of winter. https://x.com/SimonLeeWx/status/1742830508386476543?s=20 Furthermore: unlike major SSWs, minor warmings can be followed by further vortex disruption. Some forecasts hint that we could see another weakening of the vortex in mid-late Jan. For now, however, that's not worth fixating on: the vortex is weak, the NAM is negative. Enjoy it! https://x.com/SimonLeeWx/status/1742830511343456619?s=20 I'll stop this post at that point and invite your thoughts. Needless to say the next discussion needs to be around what happened next, in particular surrounding the second strat event - i.e. the technical reversal / major SSW on the 17th Jan - and what went wrong to scupper expectations. But this tweet by Marco Petagna on the 23rd Jan suggests even the pros may have been taken by surprise? A strong reflection......? Difficult to believe that only 5 to 7 days ago we were witnessing a 'technical' major #ssw sudden stratospheric warming..what a bounce back in the strength of the #spv stratospheric polar vortex!..soon set to perhaps be stronger than normal once more. https://x.com/Petagna/status/1749903441567076604?s=20

Vortex3929 I know what you mean. It was lovely here in Suffolk yesterday so me and Mrs Blessed popped out to the sticks for a pub lunch. The pub gardens already full of flowering daffodils and crocuses. Just makes you want summer to arrive quickly now.

Sometime in the next day or two I'd like to discuss the bit in bold with you and @Met4Cast please Mike. That'll be best done over in the Winter Post Mortem thread, so I'll do a post and tag you both, but basically, from the info I can find, the Canadian warming and subsequent minor warming around the 4th Jan gave us a negative NAM and some terrific charts and it was the second SSW (major) on Jan 17th that screwed things? It'll be interesting to exchange some views with you both.

GEFS members have finally all made their mind up on this afternoon's 12z run with a SSW probability reaching 100%. But according to the Op run forecast it will be a 'blink and you'll miss it' 24 hour reversal with the mean zonal wind at 10hPa 60N dropping to 0 m/s at midday on the 18th, switching easterly (negative) at midnight by -2 m/s, but then back westerly again (+ 1 m/s) by midday on the 19th. Will this be the briefest technical reversal on record? The sPV remains weak, taking until T384 to creep back up to + 9 m/s. So, a likely technical SSW, a displaced sPV and ongoing weakness. Unfortunately current model output showing little sign of any favourable impact for the UK if it's notable cold you're after. Source: http://www.weatheriscool.com/prod/ztemp_multilevels.html

For the record, anomalous warmth on the 15th February 2024:

Ridiculous for the 15th February!

Strange. The link works for me on my laptop (using Firefox browser). From your image it looks like the https protocol might be messing it up. Try copying in and pasting the link from Met4Cast into the url address line. It should look like my screen shot and not have 'https' showing on the address.

I'm unsure exactly what you're after (I can't recall seeing reanalysis charts posted), but maybe the NOAA MJO archive going back to January 2006 may help? Don't look at the "file last updated" date, but go by the date embedded within the pdf file name. Files in /products/precip/CWlink/MJO/ARCHIVE/PDF WWW.CPC.NCEP.NOAA.GOV

I wonder if the initial Canadian Warming was a fail tho? It might actually have played a role in giving us the favourable (for cold) NH synoptics in the form of a Greenland High that could well have delivered a notable cold spell. But agree that unfortunately the second SSW that occurred around the 17th January seems to have been the factor that on this occasion messed up the favourable synoptics. Win some, lose some. Here's an extract from a NOAA blog dated 16th Jan discussing the Canadian event and imminent second event: The polar vortex is acting up .....But what makes the stratosphere’s current behavior unexpected and somewhat rare is that the polar vortex seems to be more disrupted at the lower levels, closer to the stratosphere-troposphere boundary. For more than a week, high pressure has been sitting in the troposphere over Greenland. It’s possible that the recent minor stratosphere warming reinforced this Greenland high pressure, which then drove a wedge into the stretched-out polar vortex in the lowest part of the stratosphere, splitting it into two lobes. Full NOAA blog: https://www.climate.gov/news-features/blogs/polar-vortex/polar-vortex-acting Whatever, for stratosphere watchers it's been a very interesting winter - three events noteworthy in itself (although strictly speaking we await to see if the third SSW happens or not!).

You are most entitled to your opinion. Whilst there's no guarantee that a SSW will impact our little island favourably it's widely accepted that the occurrence of one can result in some of the UK's most severe winter weather, hence the interest in their occurrence. If you're looking for cold at least it's a ticket for the draw. This from the Met Office: "In recent years some extreme cold, winter snow events have all been connected to the surface effects of sudden stratospheric warmings, such as those in 2009-10, 2013, and ‘the beast from the east’ in 2018." Link: https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/wind/sudden-stratospheric-warming

A SSW not entirely in the bag yet. The latest GEFS 0z mean forecast (blue line) barely reaching a reversal around the 19th Feb before mean zonal winds recovering: The members going for a reversal has fallen away from a peak of 87% earlier this week. At this stage not a favourable trend: The SSW probability in GEFS is: 61% Source: Weather is Cool: http://weatheriscool.com/ Yesterday's 0z 10hPa minimaps from Zac Lawrence (awaiting this morning's update) showed no members going for a split; so very much looking like a displacement event. This for the 20th Feb: Source: https://www.stratobserve.com/ens_ell_minis A displacement event not surprising given it's Wave 1 forcing: Edit: Lots of info & reading about SSWs to be found in the Netweather Research library : https://community.netweather.tv/learning/research/stratosphere-sudden-stratospheric-warming-ssw-r54/

Hi. I'm wondering who this 23 year old person is that you're quoting, but I'm surprised to see anyone confidently predicting what the tropospheric impact will be at this stage from a SSW that won't occur until the 20th Feb, assuming it does indeed happen. If it does happen it's going to be a Wave 1 induced SSW which typically means a lag of at least 10 days for any impact to show. Here's a few snippets from recent research that indicate the extent of the challenge. Click on the title to go to the full paper. The role of North Atlantic–European weather regimes in the surface impact of sudden stratospheric warming events (2020 paper) While the stratospheric forcing often projects onto the North Atlantic Oscillation (NAO), the tropospheric response to SSW events, if any, is highly variable, and what determines the existence, location, timing, and strength of the downward impact remains an open question. Using large ensembles to quantify the impact of sudden stratospheric warmings and their precursors on the North Atlantic Oscillation (2023 paper) We find that there is little information in the precursor state to guide differences in the subsequent NAO behaviour between one SSW and another, reflecting the substantial natural variability between SSW events.

Latest GEFS forecasts and 84% are predicting a SSW with the mean showing this occurring around the 20th on the 0z run today: Source: http://weatheriscool.com/page11.html