Winter 2019/2020 - General Discussion

M.T. Cranium wrote: »

This is what I have come up with after the usual process. The mid-November update might be more than just a tweak this time, I could see this going several different ways as there are some unusual synoptics in various regions of the hemisphere. But the emphasis in my research study was on high-energy events. I don't think low pressure areas this winter will be fooling around, they are going to be packed with energy and moisture compared to some winters. Possibly 2013-14 is somewhat of an analogue, although I would say, shifted a bit south of that onslaught of storms. This is copied from my post on Net-weather which explains a Britain and Ireland focus in the wording.

The following is a preliminary long-range forecast for winter 2019-20, If it seems necessary, I will amend or update this forecast in mid-November.

This appears likely to be a season where high energy weather events will be grappling with a fairly robust supply of colder air at high latitudes.

Britain and Ireland can expect a very unsettled winter with frequent low pressure systems steered by a strong jet stream running a little south of its average position.

This favours a split north-south outcome where the south is often on the milder side of the storm track getting strong southwest winds and rain, while the north is more open to snow, ice and easterly winds.

The north-south divide may be enhanced by the likely appearance of strong blocking highs over eastern Scandinavia and western Russia. I don't think these are going to dominate the circulation but they will come into conflict with the zonal regime at times, forcing it to dive southeast around 5-10W and into France and the western Mediterranean. This may be another winter of heavy Alpine snowfalls and frequent severe cold spells in Germany and possibly Belgium and Netherlands into northeast France.

Battleground conditions seem likely at times across southeast England into Wales and central to northern Ireland. Frequent snow events may occur in northern and even central England, and southern Scotland, also Northern Ireland and some adjacent parts of the Republic of Ireland.

Some heavy precipitation is likely in this scenario, heavy rain in most cases in southern England, especially the southwest, and the southern third of Ireland (Munster and south Leinster).

A set-up like this may not remain steady-state, but could fluctuate north-south bringing the milder conditions further north at times, while setting the battleground further south at other times. However, the tendency will be for temperatures to average closer to normal or above in the southwest, and below normal in Scotland.

This pattern could evolve into a colder February or even March if the strong jet stream loses energy, then the blocking may be able to assert more control.

North America can expect a rather harsh winter in general, with severe cold waves at times, colliding with an active storm track from Texas northeast towards Virginia and southeastern New England. There could therefore be heavier than average snowfalls in the Ohio Valley, Midwest, and inland Mid-Atlantic to northeastern states. A pattern like this would not rule out one or two coastal blizzards in the mix. The west will be dominated by persistent cold high pressure trapped in valleys, and coastal areas will have a fairly average winter with a lot of rain, low cloud and moderate southeast winds. Snow on western mountains will be generally a bit above average but might be twice normal in the southern Rockies and northern Arizona around Flagstaff. Drought will break during the winter for California.

This may also be one of those winters where extreme cold moves south from Siberia into China, Korea and Japan.

Oscar Bravo wrote: »

A damp dark windy morning here in Castlebar and its not going to change much for the day.

Xenji wrote: »

Over 20mm of rain now in Castlebar, the Atlantic is starting to make up for the less than average rainfall we received in November.

Loughc wrote: »

Another month I reckon.

Gonzo wrote: »

unsettled or very unsettled conditions look locked in for the next 2 to possibly 3 weeks. Temperatures will alternate between mild, cool and cold between low pressure systems.

Carol25 wrote: »

So far I’m actually happy with how this winter is playing out in the west. Lots of cold frosty days, clear skies. Some deluges for a few days but then back to cold and frosty again. This pic is from Sunday looking at Christmas trees 🎄.