BBC monthly outlook
Unsettled with more progressive fronts later.
Saturday 9 November – Sunday 17 November
Unsettled, cold at times, with frequent rain
A very cold start across most of the country on Saturday with a band of rain pushing in from the west to affect western and and south-western parts of the country, perhaps some central areas too. As the rain first moves in it will meet cold air and this may bring sleet and snow on hills and, perhaps briefly to lowlands. Whilst the sleet and snow will quickly transition to rain as the front brings in milder air, the Welsh mountains may cling on to some cooler air for much of the day so snow is possible in here int the early afternoon before things dry out. Most of Scotland and eastern England will stay dry and sunny on Saturday, but will feel cool through the day. Sunday looks to be a largely dry if rather chilly day, but overnight an active front will arrive, bringing rain for most by Monday morning.
Thankfully though, the front will sweep across the UK quickly, and by midday or early afternoon rain will clear to the southeast. It will, unfortunately, scupper chances of observing the transit of Mercury across the Sun in the Southeast (with proper protective solar filters on your telescope!). For the rest of the week and weekend, low pressure is expected to linger near or just north of the UK, keeping things unsettled. After a brief, early-week stint of more progressive fronts, things will gradually transition to slower-moving, inactive fronts. This will mean longer outbreaks of rain in places, but also some longer dry interludes as well. Low pressure will keep the temperatures on the cooler side of average, and later in the week there is a chance that a few nights could be quite cold with widespread frost.
Monday 18 November – Sunday 24 November
Staying cooler than normal and often wet
For the last full week of November, little change is expected in the overall weather pattern for the UK. We will likely still see low pressure overhead or nearby keeping things unsettled and a bit cooler than normal. This low will have some slow-moving and weak fronts at times, and these will bring some longer outbreaks of rain for some parts of the country while elsewhere there are some lengthy dry spells and fine, sunny days. As the low pressure centre shifts around, there is a chance that occasionally we may see a weak ridge of high pressure creep in. If this happens overnight, widespread frost is likely to occur across the country.
This will also increase the chances for some hill sleet or snow as the next band of rain moves in over the colder air. With temperatures falling one or two degrees below average through the week, things will tend to feel a bit wintry with some cold mornings and crisp afternoons. There is also a risk that some of these slow-moving fronts could bring a locally very heavy rain event to some spots. This will likely trigger some localised flooding as well. Unfortunately, pinning down exactly where this may happen is not currently possible. The fronts will also tend to be weak, so heavy rain is not as likely, but any strengthening of small-scale low pressure could set up a heavy rain event.
Monday 25 November – Sunday 8 December
Staying wet, but increasingly windy and mild
Towards the end of November and through the first week of December, we expect there to be a gradual shift in the weather pattern from this cooler, often wet October and November into a more typical winter scenario. This will see high pressure to the east in Russia and Scandinavia weaken and allow Atlantic weather systems to return into North Europe. This will bring more active fronts and some windier weather, so things will still be rather unsettled. It is, after all, still a British autumn. The main change in that warm fronts and high pressure to the southwest will tend to send more tropical air into the UK, lifted out temperatures from below average to near or a bit above average. Overnight frosts and hill snow will gradually become less likely.
There is a risk that a few of these weather systems may bring in some very strong winds as well. Again, this is nothing out of the ordinary for this time of year, but we have so far had a somewhat unusual weather pattern dominating. However, there is a chance that this strong high pressure in Russia will be a bit more tenacious, clinging to life and sticking around deep into December. If this happens, things will stay cooler with some longer outbreaks of rain and lighter winds. As the days continue to shorten, snow chances will increase in hills and even for lowlands.
How likely will more frosts be for the rest of November, and will the odds that we see any early lowland snowstorms increases head into winter?