FI Charts ( T120+ onwards) Autumn 2020 **READ MOD NOTE IN FIRST POST**

I can't upload the charts but in deep FI, the GFS 12z is showing sleet and snow in northern, eastern and western areas on the 24th. Just for fun of course, extremely unlikely to happen. I think the GEM was showing either a 1055 or 1060 hPa high over Greenland!

Artane2002 wrote: »

I can't upload the charts but in deep FI, the GFS 12z is showing sleet and snow in northern, eastern and western areas on the 24th. Just for fun of course, extremely unlikely to happen. I think the GEM was showing either a 1055 or 1060 hPa high over Greenland!

Saw my name mentioned this early ;o . Southern areas this year please definitely worth keeping an eye on though saw it yesterday myself

Gonzo wrote: »

getting cold in this early comes with health warnings, it can mislead us into thinking we are lining up a very cold winter. There has been times before where we do get alot of blocking in October and first week of November only for the PV to power up very quickly with a very mild winter. October 1974 was one such year, lots of northern blocking in October and then a very mild winter with very little if any snow.

On the other hand sometimes a cold October can be a sign for what is in store over the winter. From what I can remember 2010 started off very warm on October 1st but within days we had cooled down considerably with northern blocking getting going and we all know what happened during November and December that winter!

Not necessarily, the warmest point of October 2010 was the 8th to the 12th when we were in a transitioning period from changeable to settled. The high pressure retrogressed from central Europe, Scandinavia around the 8th to a mid-Atlantic ridge by the 12th but exerting enough influence to keep Ireland dry. It was very sunny at first and warm for October with peach blue skies on the 11th and 12th but these sunny conditions became limited to the west as cloud came in from the east.

All this blocking is nothing unusual to be seeing in October in the context of recent autumns we've had. October 2016 had a notable Scandi High with a lot of easterly winds early on. October 2017 was largely southwesterly but November had fairly regular northerlies. October 2018 ended with a very cold northerly despite the warm start and November 2018 developed a Scandi High which brought easterly winds but due to a relatively mild continent and Irish Sea, precipitation fell as rain. Autumn 2019 was largely blocked in the high latitudes from late September onwards with October a particularly blocked month dominated by a southerly tracking jet, whilst November tended to have blocking over the Urals.

What's more unusual is the extent of it. None of the recent autumns have matched the level of blocking forecast by some models. That anticyclone to the south of Greenland projected by the GEM is record breaking and unprecedented. Such blocking has not been observed during the month of October before so have no precedents to go off of. This blocking will likely result in a good expansion of Siberian snow cover though bad for sea ice. Recent models have started to show a western based -NAO with deep low pressure from the south bringing relatively mild conditions during the third week of October despite the huge blocking over Greenland and the Arctic. Models are notorious for struggling with high latitude blocks so expect these changes.

nacho libre wrote: »

That's interesting about 2010. I wonder what October 1962 was like. Was there a Canadian warming prior to that winter?

October 1962 was a settled month with average temperatures for its time, and yes in early November.

Charts looking messy during last week of the month with potential for stronger storms than it is currently showing...charts might get more interesting by then

pad199207 wrote: »

Interesting weather nonetheless and hopefully encourages people to stay at home more.

Indeed. The weather of late was a little conducive to the virus spreading