James Peacock

31m

After the 13th wettest week on record & another 7 mm so far today, we now look to be entering a lengthy dry spell in NE Dorset. Good news for avid walkers is, the ground has continued to readily absorb the rain without becoming sodden at the surface. It’s fine out there 🙂

26m

The weekly total up to yesterday was just shy of 100 mm, highest on record for a week ending within any month Jan-Oct. Only 11 weeks in records back to 1973 have seen 100+ & those were all ones that ended within Nov or Dec. In a typical year the result would be a lot of mud.

86% of runs in the latest ECMWF ensemble have a major sudden stratospheric warming event around 6th Nov, which AFAIK would be the earliest on record (WRT Nov-Mar). It appears it'll be a mainly wave-1 driven event if it occurs, greatly displacing & distorting the polar vortex.

Historically, the displacement type has favoured the USA over Europe for resulting notably cold/snowy weather, but this skew is most pronounced for major SSWs occurring in Jan-Feb. So, I'm starting to consider that Nov 2026 *might* feature a notable cold spell in Europe.

In the meantime & regardless of whether events in the polar stratosphere reach major SSW levels, the absence of the usual strengthening polar vortex will encourage stubborn weather patterns. Hence the ECMWF ensemble now suggests high pressure could stay over N. Europe for 14+ days.

Displacement type major SSWs tend to (but not always!) lead to an increase in high latitude blocking weather patterns 3-6 weeks later, meaning there's an increased risk (not guarantee) of notably cold spells of weather affecting the N. Hem. mid-latitudes e.g. USA, Europe.

Incredibly the potential early November major sudden stratospheric warming event has gained more modelling support during the weekend. Latest IFS only briefly displaces the polar vortex far enough, while latest GFS maintains a sufficiently large displacement for many days.

The IFS scenario is perhaps too brief to reverse the 10 hPa zonal mean zonal wind at 60N for long enough to qualify as a major SSW. Whether it happens or not, there's no guarantee it would lead to cold weather outbreaks in Europe; displacement types are very unreliable for that.

Still some rain at times this week, but nothing like last week for most of the UK & Ireland. Potentially largely dry Wednesday onward, at which point it looks mild too until at least Friday, with some pleasant afternoons possible if low cloud stays away.

Signs are, this drier theme might step up a notch for the week after, with ECMWF's ensemble particularly keen on the idea. The MJO is forecast to be active in phase 3, which during El Niño events has some historical association with high pressure across N. Europe.

The MJO may then propagate on through phase 4 during 3rd week November (hard to be sure due to El Niño's interference in the RMM plots), in which case deep Atlantic low formation likely begins to feature again, with an increasing risk of wet & windy weather in the UK & Ireland.

20th-24th October 2026 was the 5th wettest 5-day period on record in NE Dorset. If not for one outlier day in late December 2013, it'd be the 2nd wettest. This month's to-date rainfall anomaly here has been catapulted from 38% to 166%.

‪Yet when walking in the forest this afternoon, there wasn’t much mud to contend with, only the most prone spots requiring some navigating around.‬ ‪The soil is generally just a little damp. The deficit after the very dry spring-summer really was enormous.‬

All sorts of fungi making the most of the moist decomposition out in the woods. A cut-back of gorse appears to suit the fly agaric very well!

Cool weather since last weekend has been chipping away at October's large positive Hadley CET anomaly v. climatology, but signs are, this reduction will cease next week, which may mean the month finishes over 1°C above the 1991-2020 average... & yet be the closest to it since January!

Interesting sea-level pressure pattern as Storm Austen reaches the eastern Channel. A lobe of low pressure extends north-north-westward from it, resulting in a wide area of light winds, while to the west, a steep pressure gradient is bringing strong winds to W Wales & SW England.

This is a good example of how, for areas near to the north of a deep low (usually the weaker side wind-wise), a ridge of higher pressure advancing from the west in the wake of it can lead to the strongest winds of the whole event.

20th-22nd October has been the 20th wettest 3-day period on record here in NE Dorset. Another 12 mm has fallen so far today. Yet still there isn't much standing water to be seen in unpaved areas - hammers home just how huge the soil moisture deficit was before this wet spell.

Onset of red & purple leaf colour in autumn occurs via synthesis of anthocyanins, which depends on many factors including ones that can vary across a single tree, & this can produce eye-catching results, as seen here.

If you ask me, a well structured non-tropical cyclone can be similarly photogenic to a well structured hurricane. Check out the curled weather front with a tight 'hook' around the low's centre, & the swathe of relatively cold & dry air wrapping in toward that core.

A week ago, some forecast model runs had Storm Austen deepening even further & tracking further north, bringing severe gales to much of southern England. Let's be thankful that's not coming to pass, while being prepared for the day, however far in the future, that it does.

Very telling how well the ground has taken in 37.5 mm of rain here during the past few days. Still good underfoot in most places. I have a feeling that won’t be the case by the end of Saturday though! A necessary sacrifice to replenish lathe water stores.

Storm Austen is looking pretty foreboding this morning as it deepens to the southwest of Ireland. For much of coastal southern England this is now forecast to be a close call on very windy weather, but Cornwall & western Devon could experience some on the rear flank of the low.

For central-southern England, this will be the 3rd spell of very wet weather this week & perhaps the wettest 24-hour period so far, with 30-40 mm possible. Still some uncertainty how far north the wettest weather extends. GFS with the lowest totals as usual - interesting trait.

As if that wasn't enough, the region also looks to be within the peak swathe on Saturday, when another 15-30 mm is possible. If totals are toward the high end of the ranges given, the 5-day period of Tue-Sat could be among the wettest on record for some parts of CS/SW England.

The overnight IFS run predicts gusts to near 80 mph for Cornwall near dawn tomorrow, then 50-60 mph gusts as far east as Devon as the centre of Storm Austen tracks eastward along the Channel during the day.

Unless it deviates markedly from the forecast, Storm Austen will be a 'Channel runner'. In winter such storms can be prolific snowmakers for southern UK, though in the past decade it's rarely been cold enough, so they're just big rainmakers instead. As will be the case tomorrow.

Following this week's very wet weather in parts of the UK & Ireland, next week currently looks changeable to begin with but perhaps much drier & calmer later on - about two-thirds of the ECMWF ensemble has high pressure building in strongly Thursday onward.

If high pressure does build across later next week, it could be slow to depart, as the stratospheric polar vortex might become unusually weak going into November, & forecasts aren't suggesting any large poleward propagation of atmospheric angular momentum until ~mid-November.

For context, a large poleward propagation of atmospheric angular momentum at this time of year tends to drive Atlantic low pressure systems across the UK for a week or so. In fact, a very large one occurred last week, the lagged effect of which is playing out through this week.

Today greeted me with a deluge, very heavy rain for nearly 20 minutes, then heavy rain for about half an hour. The day's total just over 11 mm as of 9 am, after 23.7 mm yesterday. Total rain here was a third of the usual before yesterday - October's making up for lost time.

With today's wet weather focusing on Dorset / western Hampshire as the models predicted, this week is looking very wet by local standards. Usually I find ECMWF to be biased high here, but UKMO & GFS are similar with 70-80 mm. Will be interesting to see how accurate that proves.

More context: The 00z UKMO predicts 40 mm rain here between 7 pm Thu & 7 pm Fri. While not quite a fair comparison due to the historical record being for calendar days only, this list still gives an idea how 40 mm stacks up on this area; an extremely wet day by local standards.

23rd Dec 2013 was a dreadful day in this area, as a huge windstorm moved through while the wind spent an unusually long period aligned in just the right way to maximise rainfall in the region. Result, flash flooding in places I'd never seen flooding before.

For context, a typical full October here sees around 94 mm based on the 1991-2020 average. The whole of summer 2026 saw 49.5 mm. In fact, I could add March & April 2026 to that & still be on par with the predicted totals for this week (80.5 mm).

In the shadow of the potentially noteworthy windstorm on Friday, there are some talking points with the UK weather earlier in the week. First up, moisture drawn north from the Mediterranean looks to produce 10-15 mm, locally ~20 mm for a slice of England tonight into tomorrow.

Second, a low moving through swiftly on Wednesday, which the forecast models really aren't sure how will shape up. This feature has trended deeper & more active with the potential for strong winds accompanying heavy spells of rain in southern UK - worth keeping an eye on.

Then we have the potential Friday windstorm, for which forecast modelling has trended a bit weaker but with no clarity on its path. The IFS 00z has strong winds staying fully south of the UK, while the UKMO 00z brings 70-90 mph gusts across SW England in the early hours 🤷‍♂️

Recent forecast modelling suggests a windstorm probably crosses the UK & Ireland on Friday, though it remains to be resolved how strong the peak winds will be or what time of day they will occur. There's also a chance the low is less deep & tracks further south as per latest UKMO.

That weaker, further south scenario would make the event more of a southern England rainmaker rather than a windstorm. Arguably more useful considering the hydrological drought (a stronger, further north low focuses the wet weather on west-facing slopes of high ground).

Temperature-wise, October has so far been the least anomalously warm month since April here, though it's still toward the upper end of the spectrum. Check out 1959 vying with 2023 for the warmest mean daily max temp, very impressive considering the cooler climate of the time.

Very sharp back edge to the front crossing England this morning. You can see the heavy shadow cast by its thick cloud structure.

At the 850 hPa pressure level, southern UK has a mid-October roller-coaster on the way. From ~5°C above average on Friday to ~4°C below this weekend, then back to 4-8°C above by next Wednesday. The temps we experience will vary similarly through the weekend, maybe next week.

Thursday afternoon could be nudging 20°C in Reading for example, before a cooling during Friday, then daily highs near 14°C at the weekend. Next week, positioning of a strong high pressure cell will dictate whether near-surface temps respond much to the big increase aloft.

Forecast scenarios all have a strong high affecting the UK next week, but while some have a relatively warm southerly or south-easterly flow across the UK, others have a chilly northerly or north-easterly, & some have the high right overhead with in-situ near-surface cooling.

Likely among the main reasons for this atypical October by very strong El Niño standards is that the northern Pacific Ocean's SST anomaly pattern is the inverse of what's usually observed during such events. Known as the Pacific Decadal Oscillation, it's in the 'wrong' state...

At this stage ECMWF is looking more respectable having hinted at anomalously dry conditions in northern Europe generally, though it may have been too far east with the focus of that.

The Met Office's GloSea6 might end up looking rather silly for the UK & Ireland - but again, it's too soon to say for sure. A few weeks is a long time in weather.

...as historically it's been in a positive state (cool central-northern Pacific, warmer 'horseshoe' around it) during very strong El Niño events, but this time it's negative. We're currently seeing a combination without precedent since at least 1950.