Grimsby Snow Lover

At this time of year a Scandi high can bring cold/snowy weather to the UK via easterly winds. In this instance the flow is not that cold with upper temperature (850) around 0, these need to be -5 or lower to avoid too much moderation over the north sea. Something to key an eye on though Feno13 as we head through winter.This is a very good example of what a Scand high in the right position can deliver to the uk.http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910208.gif

The GFS 0Z ensembles caught my eye this morning. The fact that the London ens in FI have colder 850s than the Manchester ens suggests to me a continental feed could occur as we head into the first few weeks of January. I know there is little showing from the GFS op at the moment that suggest this, but is one I will be keeping an eye on. http://www.wetterzentrale.de/pics/MT8_London_ens.png http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png The AO forecast http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif has to be a positive as well as the forecasted NAO http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif which seems to be heading negative as well as we enter January.

I believe the pattern changed to blocked and snowy around second week of Jan

Just out of interest, where is GP? I miss his model commentary.

Sorry lol, I meant to say Neg AO. Must be because its been positive for so long.

I thought that it was quiet too. As we head into January there are the signs of the PV weakening over the Arctic, getting replaced by a positive AO. This does not guarantee us cold and snow but could help. The trends at this range are key and need monitoring. This must be the 3rd time today though that show this.http://cdn.nwstatic.co.uk/gfsimages/gfs.20131221/18/372/npsh500.png

For what its worth the AO ens seem to be less positive than over the past few days. Nothing exciting I know, but its a start. I wonder if this supports what Nick Sussex was on about earlier? http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

Correct me if I'm wrong but that last chart screams potential doesn't it if a change to wintery weather is your thing. Just a shame its right at the far reaches of FI. Lets hope we see further similar trends on future runs. The met office update today also mentioned an increasing trend for colder weather to effect northern areas as we move towards the last third of December. Fingers crossed!

There seems to be a clear split in the NAO forecast towards the middle of the month. I would say there are slightly more negative/neutral ens than positive ones. I have checked this daily for the past week, todays negative ens are slightly more negative than they were a few days ago and the positive ens are less positive if that makes any sense. I know these can be quite unreliable at times but I thought I would add something a little more positive into an already more upbeat thread this evening. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

What frustrates me about the model runs of late are that they are CONSISTENTLY modelling this high pressure domination run after run with very marginal differences. If cold was showing in the models we all know that there would be much larger differences between runs. Having just flicked through the GFS 18z runs up to now there is still no sign of the slug of high pressure shifting anytime soon.

A crumb of comfort offered by the GFS in FI...the PV over Greenland has nearly split thanks to our pesky high migrating NW. Gone in the morning no doubt but who knows. http://cdn.nwstatic.co.uk/gfsimages/gfs.20131206/18/336/h500slp.png

As daft as it sounds those are the best ens I 've seen by the GFS all week. We have a dip at the end!!!!!!!!!!!!!! A positive straw to clutch.

I have recently been checking the NAO forecast over the past few days and for the third day in a row more and more members are pointing to a negative NAO around the middle of December. Whether this will have a direct effect on the UK is unknown, something worth watching though IMO. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

An intriguing post BFTP, what exactly has Ian Ferguson and RJS said tonight? I have scanned the past few pages but couldn't find anything. Many thanks in advance GSL

Compared with yesterday's forecast the NAO looks like going negative as we head towards the middle of December if today's run is anything to go by. Something worth keeping an eye on as this could suggest a blocked Atlantic. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

Going by this I would say there is 50-50 chance of it going negative or positive.On closer inspection perhaps more of a negative NAO as we head into the first full week of Decemberhttp://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

Wouldn't this type of setup support frost, fog and more of a faux cold at the surface?

I too hope the ECM is leading the way, but surely we all remember 'That ECM' from early last December? For this reason I am trying not to get too excited regarding any cold and snow just yet.

I flicked through the archives and to my very untrained eye I would say not. This is only one example but clearly shows a much weaker PV over Greenland. I wouldn't say there was strong HLB, but it looks more blocked than current charts are showing.http://www.wetterzentrale.de/pics/archive/ra/1981/Rrea00119811128.gifOnly in the far reaches of FI does the PV look weaker, but no way near the same extend as in Dec 1981.http://www.wetterzentrale.de/pics/Rtavn3721.pngReally hope I have read the charts wrong and the similarities are there as I want snow and cold as much as the next coldie on here.

I agree Frosty, plus having looked through the GFS 12z 850 ensembles they too paint a fairly cool to cold prolonged spell. I would not use the term 'mild' to describe the weather over the next two weeks.http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

...as is the further outlook from the met office. That said, temperatures are forecast to remain on the colder side of average for next week with a gradual return to average as we head into December. Could be a lot worse.

Couldn't agree more Bradowl. I love the cold and snow etc, but its the 19th of November not the 19th Dec/Jan! November/early December 2010 was very special and something unlikely to be repeated just yet. I live in hope though.

Nothing new there then! From my memory, during winter months the 18z GFS can throw up some lovely charts if cold and snow are your thing only to be obliterated by the 00z run in the morning. Lets see where we end up in half an hour.

Really hope you're right!! All I keep on looking at is whether the PV cranks up or not. Long may the current trends continue when winter gets going over the next few weeks.

We have quite a few trees around here that are sheading leaves too. The horse chestnut trees are turning a lovely yellow colour too.