danm

Great post.

So what’s caused our wet March with a southerly tracking jet stream? The late season SSW! As it was always going to. Please people don’t wish for one again…

B87 Where do you find the annual totals? When I look at the anomaly site from the Met Office and switch to actuals, it shows the Heathrow area getting over 1800hrs in 2022. But when I total it up month by month on the meteociel site and also this Met office site it shows just over 1,600 hours. Not sure why the disparity?

Josh Rubio yep, 18c in the sunshine today has felt very pleasant.

raz.org.rain hmmm that would be a recipe for what we had in April/early May last year with clag in eastern Britain, sunniest in the west. From a IMBY perspective i'd prefer a SE to E flow to avoid that.

All those showers dried up before they reached here so it’s been a totally bone dry day with lots of sunny spells. A short while ago: It then clouded over but stayed dry, now back to a few sunny breaks again. A much better day than forecast. 17c the high.

Been a decent day here with sunny spells. 15c at the mo.

Arch Stanton yes true regarding current very high SST's. I also think the issue we've had over the last 18 months is continually being stuck on the wrong side of the jet stream. Whereas in 2018 and 2022 we had prolonged spells of being stuck south of the jet stream, which gave us lengthy dry and hot weather, apart from a few months the last 18 months has seen us stuck underneath the jet or just to the north of it. if we synoptically get another displacement north of the jet, as we had a couple of years ago, there is nothing to suggest we won't get into another prolonged dry spell. I suppose what is true is that with very high SST's, the wet spells we do get will be more intense.

No comment on the models this morning? In a nutshell, we have a nasty little feature tomorrow that'll give many of us cool, windy and damp weather. After that, pressure builds to the south and SE, bringing sunshine and temperatures up to 20c across these areas by Thursday and through the weekend. The ECM then makes more of that NW'erly blast, bring cooler temperatures again by early next week, but the GFS doesn't make too much of that and quickly rebuilds pressure from the west, settling things down nicely. The UKMO only goes out until next Sunday, but looks similar to the GFS in that it looks a lot less primed for a NW'erly in the way that the ECM shows. Step by step, this is what each run shows for tomorrow: Then later this week with the build of pressure to the south and south east: Then towards early next week, here's how each of them deal with the chillier NW'erly: ECM: UKMO only goes out to Sunday: GFS - keeps any NW'erly very brief, with a quick rebuild of high pressure: What about the means: Less bothered about 850's at this stage, so looking at pressure, the GEFS has a short dip before pressure builds again by the middle of next week - graph is for London: ...and for Manchester: The ECM mean unfortunately is less keen on a quick rebuild of high pressure and keeps any rebuild fairly weak: So we can confidently say that tomorrow looks awful for many, then much warmer, sunnier and drier across the south/SE midweek onwards and into the weekend, less so further north and west, then uncertainty over the potency and longevity of the NW'erly and how quickly and to what extent high pressure rebuilds into next week. Original post: https://community.netweather.tv/topic/99814-model-output-discussion-spring-has-sprung/?do=findComment&comment=5055995

Tomorrow looks downright awful, but then there is hope for later this week:

No comment on the models this morning? In a nutshell, we have a nasty little feature tomorrow that'll give many of us cool, windy and damp weather. After that, pressure builds to the south and SE, bringing sunshine and temperatures up to 20c across these areas by Thursday and through the weekend. The ECM then makes more of that NW'erly blast, bring cooler temperatures again by early next week, but the GFS doesn't make too much of that and quickly rebuilds pressure from the west, settling things down nicely. The UKMO only goes out until next Sunday, but looks similar to the GFS in that it looks a lot less primed for a NW'erly in the way that the ECM shows. Step by step, this is what each run shows for tomorrow: Then later this week with the build of pressure to the south and south east: Then towards early next week, here's how each of them deal with the chillier NW'erly: ECM: UKMO only goes out to Sunday: GFS - keeps any NW'erly very brief, with a quick rebuild of high pressure: What about the means: Less bothered about 850's at this stage, so looking at pressure, the GEFS has a short dip before pressure builds again by the middle of next week - graph is for London: ...and for Manchester: The ECM mean unfortunately is less keen on a quick rebuild of high pressure and keeps any rebuild fairly weak: So we can confidently say that tomorrow looks awful for many, then much warmer, sunnier and drier across the south/SE midweek onwards and into the weekend, less so further north and west, then uncertainty over the potency and longevity of the NW'erly and how quickly and to what extent high pressure rebuilds into next week.

Daniel* Yep February has become a lot wetter, but then March, April, May and June have all become drier relative to the 1961-1990 period. March is 18% drier, April 5% drier, May is 9% drier, June 7.2% drier. In fact, looking back at the records, our Autumns and Winters have become a fair bit wetter, our March to June period has become drier and our July to September period looks largely flat. September is a little drier, July and August very slightly wetter. Overall average rainfall totals for Heathrow between 1961-1990 was 596.58mm per year, up to 614.98mm between 1991-2020, so a 3% increase overall. Average sunshine totals for Heathrow between 1961-1990 was 1,519.44 hrs per year, up to 1,674.81 hrs between 1991-2020, a 10% increase.

stainesbloke for the October to April period id say yes. It is more bland. We rarely get extremes of cold now. But in Summer, the extremes have increased in recent years. All time record broken twice within the space of 3 years - 2019 and 2022, 40c barrier smashed, more frequent 35c+ days etc.

Arctic Hare for London, the 1991-2020 period was 10% sunnier than 1961-1990, but only 3% wetter.

Well the stats definitely show it has got a little wetter over the last few decades but also sunnier. Whether that continues I don’t know.

Sunshine hours have increased, as has rainfall totals a little over the last few decades. It’s possible to have both increase - the wet spells are becoming wetter, yet sunshine totals can still increase at the same time.

100%. I know this is the moans thread but there are at times some very extreme reactions. Yes, the last 18 months have been exceptionally wet, but we’ve also been through lengthy dry spells over the last 10 years. No reason why we won’t go through another one later this year.

cheese agree, that wind has been annoying but we’ve had decent amounts of sunshine, especially today, and it’s been warm in that sunshine.

WYorksWeather agree. We’re clearly scarred by the last 18 months of way above average rainfall, but turn the clock back to August 2022 and with a parched landscape we were talking about severe drought.

Nice day overall today. Cooler temperature wise than yesterday but feels warmer as the wind isn’t as strong…

Augusta Snow yep there have been a few wetter than average years more recently but prior to that there were more drier than average.

Daniel* When I look at the anomaly maps I tend to hone in on the spread across a wider area, as lasering on one small location can highlight very localised events that may have resulted in one area having slightly more than average rainfall versus another area not far away having less than average. Those are likely cause by a couple of intense showers that could have dropped a tonne of rain in a few spots. E.g. look at the map below for 2019: Patches of the same region in the SE/EA had slightly higher than average rainfall, whereas a short drive away it was lower than average. Looking at the entire SE/EA region shows it mostly at about average rainfall for 2019, a few places slightly above and a few slightly below. That to me suggests that the places that had slightly above average rainfall must have got those totals from localised, short events such as a few intense showers. The region as a whole there is about average for rainfall in 2019.

The breeze is a lot less today, lots of sunny spells and feeling pretty warm out there in the sunshine. 16c at the moment.

Warm with sunny spells, but breezy. 20c