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**Gonzo** · 17-09-2020, 19:02

GEM also going for the cold plunge with a Greenland high possibly setting up shop.

Icon looks very similar too:

This mornings ECM going for it too and this evenings ECM is now rolling out so in a bit we shall see what the ECM makes of it.

If this verifies it brings summer to a very definite end and into Autumn proper with shades of winter.

hatrickpatrick · 17-09-2020, 19:55

Why is it never December when charts like this appear

I presume at this time of year all we'll get from such a setup is bitterly cold mucky rain?

I wonder if this is at all related to the ongoing SST anomaly, which as myself and Sryan mentioned in the Winter thread is currently analogous to both 2017 and 2010 which both contained strong Northern Blocking events in their Winters - although also bearing a strong resemblance to 2013, which IIRC was just horribly wet and stormy for us.

**Gonzo** · 17-09-2020, 20:32

ECM going for it too this evening but it's rather short lived with high pressure not far away.

The cold does looks potent with temperatures between 4 and 6C below average for the time of year. Imagine if we got this in late December or early January.

Autumn certainly looks like it's going to bite for a few days.

It's possible that once this get's out of the way we end up with an area of high pressure and some frosty nights to start off October. However as the Polar Vortex is getting going and zonality is enhanced we will probably bring back the Atlantic proper from October instead.

Meteorite58 · 17-09-2020, 23:44

Yeah as Gonzo said above models seem to be locking on now to a considerable cold plunge the second half of next week with signs of possible brief ridging at the end of the weekend or thereabouts but no certainty of this. Currently showing temps generally in the 10 to 15C range by day and some very low temps at night making frost possible in sheltered areas. Could be a stiff Northerly component to the wind later next week so giving an added chill at times especially in coastal areas. Extra quilts, jumpers, jackets and the like to be got ready it looks like, certainly will give no doubt that summer is over.

It has the look of an abrupt change in the seasons.

**Danno** · 18-09-2020, 00:17

Quote:

Originally Posted by Meteorite58

Yeah as Gonzo said above models seem to be locking on now to a considerable cold plunge the second half of next week with signs of possible brief ridging at the end of the weekend or thereabouts but no certainty of this. Currently showing temps generally in the 10 to 15C range by day and some very low temps at night making frost possible in sheltered areas. Could be a stiff Northerly component to the wind later next week so giving an added chill at times especially in coastal areas. Extra quilts, jumpers, jackets and the like to be got ready it looks like, certainly will give no doubt that summer is over.

Even the guys in Spain and on the north coast of Africa are going to feel this plunge too! Quite a marked drop in temperatures if this plays out as the models predict!

Spain next Friday night:

And the following day widespread mid-teens in Spain with just the usual coastal resorts getting into the low 20s along with N Africa.

Meteorite58 · 18-09-2020, 20:42

Usually the charts moderate a bit as you get closer to an event, the last couple of runs are showing colder conditions I reckon from midweek with some very cold nights, ECM showing getting down to around 4C and 3C but I reckon the ECM is normally quite conservative with cold temperatures so could even get a bit lower. GFS looks windier than the ECM . GFS showing it a lot wetter also, ECM has really lowered the expected rainfall amounts not developing the lows from midweek, GFS continues to develop them hence showing stronger winds and higher rainfall totals. If we had wind like the GFS showing it would give some Windchill, skinning! Interesting that the UKMO is more like the GFS showing some very cold wet and windy weather , hmmm.

The ridge around Sun/ Mon doesn't look like lasting long either, GFS doesn't develop it at all.

EDIT : Looking back over the Oz ECM, it was much more in line with the GFS and UKMO, maybe the 12Z was an outlier. Will see in the morning.

sryanbruen · 23-09-2020, 13:05

Looks to me that there's likely to be quite a dip in the jet in the eastern US through early October and a corresponding ridge-trough-ridge pattern over Europe, with the trough centred over the UK/Ireland. Go figure! This, like an Omega High in summertime, can be very difficult to push away and gives off some exceptionally wet months. I'm thinking months like October 2004, November 2009 etc - look away Corkians!

Atlantic looks to be going through a quieter phase now for hurricanes or tropical storms so should be less uncertainty caused by them for the time being though there is still Teddy to contend with at the moment. However, for our part of the Atlantic, it looks to be full steam ahead with slow moving depressions giving off a lot of rain.

**Gonzo** · 23-09-2020, 13:37

looks fairly chilly as well over the next few weeks with plenty of north-west to south-east lows and the possibility of northern blocking getting going as we move towards winter.

pauldry · 23-09-2020, 14:02

So a fairly freezing end to Autumn followed by a mild Winter (again)

Some years we get our coldest nights in October (sad but true)

compsys · 23-09-2020, 14:05

Quote:

Originally Posted by pauldry

So a fairly freezing end to Autumn followed by a mild Winter (again)

Some years we get our coldest nights in October (sad but true)

Even worse, the temp in Mullingar and Dublin Airport got down to -3º this May!

We barely got close to freezing throughout the entire winter yet managed to plunge below freezing two weeks out from summer.

**Gonzo** · 23-09-2020, 16:08

I remember the build up to last winter, we had plenty of north-west to south-east lows last October and just as these were starting to turn wintry on high ground towards the end of October we were into a relentless very mild winter from first week of November right across to early March and then we got the dry and mild Spring.

Hopefully this isn't another case of cold October followed by a very mild winter but we shall see.

Meteorite58 · 23-09-2020, 22:47

Lp continues to dominate out to +240 hrs from the ECM 12Z and beyond into FI by the GFS. Trending quite wet and on the cooler side in general. Some big rainfall totals showing up especially in the SW.

https://www.tropicaltidbits.com/

sryanbruen · 25-09-2020, 12:36

Surprised it hasn't been noted here but the GEFS now has 31 ensemble members (counting the control and operational runs) instead of the former 21 as NOAA recently upgraded them. You can count this as 32 if including the parallel run too.

An increasingly wet outlook into October with a clear zonal sinewave as some days average and others cool - oscillating air masses. But on the whole, favouring the cooler than average side.

**Gonzo** · 25-09-2020, 13:09

not much in the way of rain over the next week which is good. It's been a great September and our only real taste of summer since May and now a very definite changeover to Autumn rather than a gradual trend towards Autumn.

pauldry · 25-09-2020, 13:18

In Sligo weathers been great this year bar first 2 weeks of July which were dark and cold.

October looks like it will be our worst weather since start of March. A cold and wet one.
However it could always get mild or warm mid month which sometimes happens

Rainfall has generally been normal or below here since Mid March.

18-09-2020, 20:42	#21
Meteorite58 Registered User Join Date: Jan 2014 Posts: 8,978 Adverts \| Friends	Usually the charts moderate a bit as you get closer to an event, the last couple of runs are showing colder conditions I reckon from midweek with some very cold nights, ECM showing getting down to around 4C and 3C but I reckon the ECM is normally quite conservative with cold temperatures so could even get a bit lower. GFS looks windier than the ECM . GFS showing it a lot wetter also, ECM has really lowered the expected rainfall amounts not developing the lows from midweek, GFS continues to develop them hence showing stronger winds and higher rainfall totals. If we had wind like the GFS showing it would give some Windchill, skinning! Interesting that the UKMO is more like the GFS showing some very cold wet and windy weather , hmmm. The ridge around Sun/ Mon doesn't look like lasting long either, GFS doesn't develop it at all. EDIT : Looking back over the Oz ECM, it was much more in line with the GFS and UKMO, maybe the 12Z was an outlier. Will see in the morning. Last edited by Meteorite58; 18-09-2020 at 22:37.

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17-09-2020, 19:02	#16
Gonzo Moderator Join Date: Aug 1999 Posts: 12,826 Adverts \| Friends Mod: Weather, ZTest	GEM also going for the cold plunge with a Greenland high possibly setting up shop. Icon looks very similar too: This mornings ECM going for it too and this evenings ECM is now rolling out so in a bit we shall see what the ECM makes of it. If this verifies it brings summer to a very definite end and into Autumn proper with shades of winter.

17-09-2020, 19:55	#17
hatrickpatrick Registered User Join Date: Jun 2005 Posts: 17,094 Adverts \| Friends	Why is it never December when charts like this appear I presume at this time of year all we'll get from such a setup is bitterly cold mucky rain? I wonder if this is at all related to the ongoing SST anomaly, which as myself and Sryan mentioned in the Winter thread is currently analogous to both 2017 and 2010 which both contained strong Northern Blocking events in their Winters - although also bearing a strong resemblance to 2013, which IIRC was just horribly wet and stormy for us.

17-09-2020, 20:32	#18
Gonzo Moderator Join Date: Aug 1999 Posts: 12,826 Adverts \| Friends Mod: Weather, ZTest	ECM going for it too this evening but it's rather short lived with high pressure not far away. The cold does looks potent with temperatures between 4 and 6C below average for the time of year. Imagine if we got this in late December or early January. Autumn certainly looks like it's going to bite for a few days. It's possible that once this get's out of the way we end up with an area of high pressure and some frosty nights to start off October. However as the Polar Vortex is getting going and zonality is enhanced we will probably bring back the Atlantic proper from October instead.

17-09-2020, 23:44	#19
Meteorite58 Registered User Join Date: Jan 2014 Posts: 8,978 Adverts \| Friends	Yeah as Gonzo said above models seem to be locking on now to a considerable cold plunge the second half of next week with signs of possible brief ridging at the end of the weekend or thereabouts but no certainty of this. Currently showing temps generally in the 10 to 15C range by day and some very low temps at night making frost possible in sheltered areas. Could be a stiff Northerly component to the wind later next week so giving an added chill at times especially in coastal areas. Extra quilts, jumpers, jackets and the like to be got ready it looks like, certainly will give no doubt that summer is over. It has the look of an abrupt change in the seasons.

23-09-2020, 13:05	#22
sryanbruen Registered User Join Date: Aug 2015 Posts: 11,145 Adverts \| Friends	Looks to me that there's likely to be quite a dip in the jet in the eastern US through early October and a corresponding ridge-trough-ridge pattern over Europe, with the trough centred over the UK/Ireland. Go figure! This, like an Omega High in summertime, can be very difficult to push away and gives off some exceptionally wet months. I'm thinking months like October 2004, November 2009 etc - look away Corkians! Atlantic looks to be going through a quieter phase now for hurricanes or tropical storms so should be less uncertainty caused by them for the time being though there is still Teddy to contend with at the moment. However, for our part of the Atlantic, it looks to be full steam ahead with slow moving depressions giving off a lot of rain.

23-09-2020, 13:37	#23
Gonzo Moderator Join Date: Aug 1999 Posts: 12,826 Adverts \| Friends Mod: Weather, ZTest	looks fairly chilly as well over the next few weeks with plenty of north-west to south-east lows and the possibility of northern blocking getting going as we move towards winter.

23-09-2020, 14:02	#24
pauldry Registered User Join Date: Jul 2009 Posts: 4,678 Adverts \| Friends	So a fairly freezing end to Autumn followed by a mild Winter (again) Some years we get our coldest nights in October (sad but true)

23-09-2020, 16:08	#26
Gonzo Moderator Join Date: Aug 1999 Posts: 12,826 Adverts \| Friends Mod: Weather, ZTest	I remember the build up to last winter, we had plenty of north-west to south-east lows last October and just as these were starting to turn wintry on high ground towards the end of October we were into a relentless very mild winter from first week of November right across to early March and then we got the dry and mild Spring. Hopefully this isn't another case of cold October followed by a very mild winter but we shall see.

23-09-2020, 22:47	#27
Meteorite58 Registered User Join Date: Jan 2014 Posts: 8,978 Adverts \| Friends	Lp continues to dominate out to +240 hrs from the ECM 12Z and beyond into FI by the GFS. Trending quite wet and on the cooler side in general. Some big rainfall totals showing up especially in the SW. https://www.tropicaltidbits.com/

25-09-2020, 12:36	#28
sryanbruen Registered User Join Date: Aug 2015 Posts: 11,145 Adverts \| Friends	Surprised it hasn't been noted here but the GEFS now has 31 ensemble members (counting the control and operational runs) instead of the former 21 as NOAA recently upgraded them. You can count this as 32 if including the parallel run too. An increasingly wet outlook into October with a clear zonal sinewave as some days average and others cool - oscillating air masses. But on the whole, favouring the cooler than average side.

25-09-2020, 13:09	#29
Gonzo Moderator Join Date: Aug 1999 Posts: 12,826 Adverts \| Friends Mod: Weather, ZTest	not much in the way of rain over the next week which is good. It's been a great September and our only real taste of summer since May and now a very definite changeover to Autumn rather than a gradual trend towards Autumn.

25-09-2020, 13:18	#30
pauldry Registered User Join Date: Jul 2009 Posts: 4,678 Adverts \| Friends	In Sligo weathers been great this year bar first 2 weeks of July which were dark and cold. October looks like it will be our worst weather since start of March. A cold and wet one. However it could always get mild or warm mid month which sometimes happens Rainfall has generally been normal or below here since Mid March.