Derecho

danm Meanwhile here it is drizzly and only 6C

Don We are looking at 9.4C to finish the month So that would bring the CET for the second half of April to 7.7C. The chilly uppers are hanging on longer then expected with winds very slack later this week allowing for chillier nights. If this came off, the CET for the second half of April will be colder then the first half of February.... Also I wonder how many Aprils have recorded their coldest running mean on the 30th? Odd for a month that typically warms as it progresses. It really has felt like a backwards April and a poor one...

Addicks Fan 1981 Easterly winds are most frequent during April and May so it's hard to distinguish whether an SSW is responsible here

Dare i watch the GFS 06Z Fair enough, it wasn't a straw man argument however, it was just based on logic and what the graphs show. I agree that we can still see cooler weather in a warming climate, I don't think anyone can argue that. Though all we know at this stage is that global temperatures will increase (barring a big volcanic eruption) but atmospheric circulation determines how that extra heat is distributed. What that means locally I wouldn't want to guess. You could see 10 years of very warm April's in Sweden the next 10 years, maybe not. The long term means however will paint the best picture for changes and global temperatures will very likely carry on increasing regardless. What we are seeing is more frequent warmer extremes and shorter cooler / cold episodes. These can still be extreme as March 2018 shows but will be compensated by greater warmer extremes elsewhere. The ease of tapping into very warm airmasses is what is making colder then average months harder to come by these days but April 2021 shows it's still possible.

I'm very capable of reading graphs thank you and my comment still stands. The solid black line is only a 10 year running mean and is too short. The dashed line is a more appropriate long term average that is still increasing on almost all the graphs you posted.

Dare i watch the GFS 06Z 10 years is too short to define a climate, you need at least 30 for it to be statistically meaningful. If you took the 2001-2010 average for December in the CET series, it only came out at 4.0C, nearly a degree lower then the 1971-2000 average. Yet 2011-2020 had an average CET of 6.0C for December, 2 degrees warmer then the decade prior... The longer term means, including the ones you have posted for Sweden are heading upwards...

I don't know how you can conclude that from the graph you posted before? 2011, 2014, 2015, 2018, 2019 and 2020 all appear to be just as warm as the warm April's in the 2000s with 2011 record breaking. Looks like the 30 year running mean(?) is almost at an all time high. You aren't going to get warmer April's with every single passing year. There will be variability. Climate change means I'm pretty sure you'll see those kind of April's more regularly unless atmospheric circulation fundamentally changes.

Afternoon all, so after an unremarkable week of CET returns (even slightly above average with the last 7 days at 8.2C) it looks as though the CET may actually now be close to or even above 10C at the end of the month. According to the 00z EC control, we have a few slightly chilly days up until the 26th which should take the CET down to around 9.7C. After that the daily CET returns are above 10C again. 00z EC control is slightly on the warmer side of the ensemble mean so something between 9.8C and 10.2C is probably in the right area. Another notably above average month yet again if this run comes off. GFS handles the weekend low a bit differently so is cooler however to end the month.

We will see, I think it will probably remain chilly most days until the 27th. After that is more uncertain, at this time of the year if you cut off the Arctic feed, suddenly easterlies can turn very warm but no sign of that yet. Looks like the chillier air may gradually dissipate but a coldish outlook overall, especially in the east.

EC 12z control has the CET finishing on 9.6C. Pretty close to the ensemble mean overall with the monthly CET dipping below 10C on the 23rd. According to this, first half CET would be 11.1C, second half would be 8.0C so quite a contrast.

I can see those darker skies just to the east of Hull from the top of my office. It is grim.

Whether we get temperatures slightly below normal or more substantially colder then normal, will depend on cloud cover. Cloudy days will suppress maximums a lot with the cold uppers. You can imagine a setup with the same T850s... cloudy days and clear nights will return much colder values then sunny days and cloudy nights.

The chilly weather over Central Europe keeps subtly getting upgraded, so to be fair to @Daniel* this is looking like quite the transition now till the end of the month given recent exceptional warmth. The warmth of earlier in the month is transferred to central Asia instead. Some above average temperatures in the Arctic for the first time in a while as the cold air bottled up there is moving into Central Europe. Global temps nudging downwards a tad as well from the record highs we have been seeing this April. The El Nino feedback perhaps beginning to wane somewhat.

EC00z control this morning has us finishing at 10.2C but this is on the mild side of the ensemble with a warm day on the 30th. EC 00z control GFS 12z operational however... Finishes at just 9.2C however this is on the cold side of the ensemble mean. 9.7C would be a more sensible option right in the middle.

I remember the very first night in Buckinghamshire when the pubs opened. We went out to my local and even with a jacket on it was far too cold. We endured it for the sweet taste of a post lockdown pint however. We also got two falls of snow that led to accumulations. The first half of the month in particular, was really cold.

Yes chilly minima will be present in the west, though if away from the chillier easterly feed it could get quite warm during the day in these areas.... ... but looking at the model output this morning it does look a bit on the chilly side widely into the later stages of the month with less of an east-west split. A CET of under 10C is possible.

BlueSkies_do_I_see Yup it wouldn't take much. We will probably end up with a chilly east and mild west of the UK, so where that boundary ends up will have a big bearing on the CET as Pershore and Stonyhurst are more western sites.

I think April 2021 has to be synoptically one of the most unusual months I can remember.

reef Maybe that is some outflow from the dying shower that just passed your area? It has been very windy here today, lots of howling noises... I remember one night early last April that saw a lot of branches fall off trees and bins blown over. I'm pretty sure Hull would have seen a gust even higher then 47mph that night but that might have been within a heavy shower that passed.

Today feels like a classic April showers day here. A pretty brisk wind but plenty of sunshine as the showers have eased off recently. A tad on the chilly side.

Latest 12z control from the EC is pretty nondescript with high pressure but on the chilly side for a small number of days. More so in the east with Stonyhurst or Pershore often being the warmest site. Makes sense given the overall pattern and the cooler air from the continent grazing the SE. However the EC12z control was on the colder side of the ensemble mean from the 24th to the 29th. So the CET drops down to 9.9C here. Early 10s guesses are looking good at the moment.

Daniel* Fair enough, just goes to show how warm it has been there though with these cooler temperatures being only just below the 81-10 average. GFS looks depressingly familiar at D10 but the EC remains rather chilly at this time with a high to the NE

Don Yes some cooler weather is certain for next week but milder weather seems to occur far more effortlessly these days. It won't take much for it to return.

WYorksWeather Another problem is you have got warmer then average SSTs around the UK so that is going to moderate cooler airmasses. If we get a retrogressing high to Greenland you might get a few daily CETs in the 4s or 5s but I don't think that will happen. Remember at the start of April the models were expecting cold at one stage but that remained further north and we ended up with cyclonic SW winds instead. It wouldn't surprise me if the high ends up closer to the UK tbh

The latest EC control has the CET holding up to 10.3C on the 23rd. Next week looks average at worst and the 21st and 22nd on the control actually return daily means above 10C so not much of a drop in the CET overall to be honest.