comet
-
Posts
264 -
Joined
-
Last visited
Content Type
Forums
Blogs
Gallery
Events
Learn About Weather and Meteorology
Community guides
Posts posted by comet
-
-
There are some cracking ensembles to view. After the bareness of the last 4 winters an almost countrywide snow event bringing 6 to 12 inches of snow would go some way to compensate but if it all implodes and we end up dry and cold with the wishbone effect then that would really rub salt into the still open wounds of the last few years.
-
excellent run so far only problem being the adjustment south of the low in just 6 hours from the 12z. At this rate by this time tomorrow we will be wondering what all this talk of snowmagedon was all about when the low is modelled 500 miles or more to the south of the UK.
-
1
-
-
Hoping the 18z does not wind the low up like the 12z it makes it less believable plus of course it introduces less cold uppers and higher dewpoints..
-
32 minutes ago, Catacol said:
Tamara got there first... but the anticipated WDT update today is above expectations. Injection of atmospheric momentum will, without doubt, serve to extend the period of amplification and counter any sense of a flat Nina pattern. For me this means my December best guess is bust already, because I neither expected such an early surge of renewed poleward energy nor to such a level. However the possibility of this was always made clear - timing out.
So it’s time to modify that best guess. Fergie’s tweet is significant - it suggests the jet will break out to the south with amplification allowing maintenance of heights to the NW. Trop led pattern continues to suggest the vortex will not lead the dance yet (another surprise if I’m honest) and chances of a below average December are increasing. Damianslaw’s earler post was an excellent illustration of possible pattern shape.
Going forward this all sets up for a rather interesting January... earlier than hoped for when posting a couple of weeks back. MJO into 7-8-1 orbit by months end may indeed now be a possibility on the back of the AAM spike and weak Nina pattern. End product? Do not rule out easterlies in early January with bumper lows running into the block. As GP has said - if we can get enough cold pooling over Russia, and extended forecasts are seeing pooling in central Russia 6-8 degrees below average by mid December, then a severe spell of weather in mid winter is not beyond the bounds of possibility now.
Vortex recovery or a deepening Nina could still, of course, override this. Ill be checking ENSO conditions carefully later...
Seems to me they are playing catch up. Signs were there long before now. Lol we could still all be wrong.
-
I see other posters are now jumping aboard the cold train for December and perhaps onwards although with different reasoning my own and others although if all roads lead to winter nirvana then who gives a jot how we get there. Ecm this evening does seem to fast but can not be completely discounted. Love to see the gfs somewhere near correct (not quite as deep a low) giving a countrywide major snow event. Massive difference with the gfs extended output between the 06z and 12z the 06z throwing a strong Alaskan ridge into the Arctic but completely missing on the 12z thus not as amplified until FI near the end.
0
-
Why put so much emphasis on what the Met have to say. They have Been spouting cold for the first half of Dec for a week at least, now if it is going to be milder it does not fill you with confidence in what they have to say when they could not see this coming until it's right on their door step.
I said yesterday or the day before no one has a crystal ball. Let's see what this afternoon and this evening bring.
-
3
-
1
-
-
2 hours ago, Mucka said:
Although the output looks poor on the face of it I think it is possible we are seeing the models seeing a new evolution which will lead to Northerly, just a later one than originally modelled.
GFS/UKMO 144 comparison
Rather unintuitively the new flatter pattern out to mid term may help us so long as we can get some amplification upstream by allowing the shortwave lows to eject East and phase with the main trough retaining some Atlantic blocking not allowing the Atlantic in proper.
UKMO is better upstream than GFS and the 168 chart would likely show a Northerly which could become accentuated by those shortwaves ejecting East. There is a danger of a West based neg NAO developing if they phase to far North and/or West but if they phase further South and/or East they could actually be a big help.
If this is correct we will see a slow transition to a Northerly anything from one to a few days later than initially modelled recently dependent on how clean any development is.
All bets are off for me until we see if this signal is correct and and how it is modelled with any consistency but don't be surprised to now see the first programmed Northerly fail only to be replaced by another.
Fascinating developments this morning.
My exact thoughts when viewing the models this morning.
Keep the faith people's the freeze is just delayed not postponed.
-
1
-
1
-
-
Well that ecm op run was a stinker from as early as 120 onwards as the Atlantic low deepens and heads north, certainly was not expecting that and of course the following synoptics were impacted with zero ridging etc. Really hope and reasonably confident that the ECM is modelling this all wrong judging by the gfs and ukmo runs this afternoon. The pub run should give us a clue with tomorrows runs hopefully confirming one way or other.
-
I think most posters on here know where our weather is heading from the middle of next week and that is into the freezer. It could be for quite some time as well.
should be an excellent afternoon and evenings model watching.
-
3
-
-
You almost could not draw it any better, and all just 8 - 9 days away. I know at that range it is still a long shot but it is also very plausible.
-
1
-
-
This is lining up to be a pub run special me thinks.
-
1
-
-
43 minutes ago, feb1991blizzard said:
Nick I think the shortwave spoilers occur because the longwave pattern isn't conducive, so the shortwaves will then appear at the wrong time / take the wrong track to deliver UK cold, I think all the pro's say this anyway, that the longwave pattern drives the shortwave pattern, however, please don't change your analytical style as its brilliant - its the best and simplest way to read the charts and understand what needs to happen to deliver UK setups that deliver cold IMO.
Very true. Sometimes though the models make problems that are not really there ie inventing annoying little shortwaves etc that mysteriously disappear on later output or get brushed aside by a longwave pattern conducive to northern blocking. More than happy with this afternoon and evening model output overall and fully expect to see a much improved ecm tomorrow.
-
4 hours ago, Seasonality said:
Well said Karlos. The thing about this forum is that there are plenty of enthusiasts, perhaps even a few dramatists if I'm being cheeky
, but only a few experts. Tamara is very much one of the few and her posts are always worth paying attention to.
Her latest update will not be very accurate if the 06z gfs run verifies. Remember we are all amateurs on here there are no experts with a crystal ball. the UK model was the first to delay ridging in the Atlantic because of trough disruption while the other big two went ahead guns blazing now they are playing catch up. We could be on the cusp of something special and while I have lost all faith in Mr Cohen it would fantastic if he was right for once.
looking forward to the afternoon and evenings runs with great expectations.
-
3
-
-
5 minutes ago, bluearmy said:
As I understand it, the upcoming potential reversal (or weak zonal flow) in the strat is led from the bottom up so will possibly not get to the very top parts of the strat. the Berlin charts have been showing a strong vortex high up re zonal flow but displaced well away from the pole
That's true lets just hope it stays there.
-
2
-
-
The Canadian warming that we saw late October early November is still playing its hand and that is why we have this northern blocking and Atlantic ridging that we are seeing in the models. I would not be overly concerned by the ECM run this evening best to wait and see where we stand in the morning. Have a feeling there will be many relieved posters by then.
What does concern me though is what the gfs strat charts are showing in the longer term with warming at the 1mb level not penetrating into the Vortex but rather skirting around the periphery as if stirring and strengthening the vortex.
-
8 minutes ago, Frosty. said:
Unbelievable in here, you would think this week is going to be mild but it certainly isnt!.. The Ecm 12z indicates, windchill, frost, ice and Snow in the reliable timeframe!
Yes it is going to be rather cold to cold with some lucky locations seeing snow but it is a long way from a big freeze. Even on the coldest days to come IE Wednesday to Friday any lowland snowfall over England will not hang around for long with max temps of 3 or 4c, Having said that the charts and the weather are 100 times more interesting than what we have seen the last few years and of course there is a real possibility of a potent cold spell (perhaps freeze ) in the not to distant future.
-
2
-
-
4 hours ago, JBMWeatherForever said:
A very good further outlook from Exeter. Does anyone who watched the weather for the week ahead on the Beeb, just now, though, think like me, that they were underestimating the cold for later this week or do you think they are on the money. Just seemes that 6 or 7c for much of central and South East England on Wednesday and Thursday seems a bit generous given the synoptic and likely airmass at that time ?
generally speaking away from cities and coastal areas a good rule of thumb from late November to late January is add 10c to the upper 850 temps. For example if you have 850's of -6c then the surface temps will be around 4c. It works pretty well for my area which is about 75m above sea level. Inversions are a different matter of course and also once you get into February the lapse rates go up so by mid Feb its around +12 and +13c at end of Feb. Television forecasts always seem to over do temps for some reason or other.
-
1
-
2
-
-
1 hour ago, summer blizzard said:
Note how even the colder parts of the vortex have become disjointed by day 10.
The breakaway portion over northwestern Russia, very interesting with the direction that is heading.
If the flow to the north east connects with the low over northwestern Europe then the uppers would soon plummet. All academic at that range, but nice to ponder what could be.
-
1
-
-
Well if its prolonged cold you want then you could not ask for much better chart than the ecm t240 chart below.
The ukmo run this morning is again less than enthusiastic on cold reloading, but both the ecm and gfs see further amplification in the north Atlantic. The ecm being by far the best for cold prospects from the north and east.
For most of us though a rather cold week to come with a lucky few seeing some snow.
-
3
-
-
53 minutes ago, coldwinter said:
Interesting, the research of Wenjun Zhang however found a correlation between an eastern pacific based La nina with a negative NAO. And central based with a +VE NAO.
https://link.springer.com/content/pdf/10.1007%2Fs00382-014-2155-z.pdf
agreed an East based nine is better for our chances of cold, So they say.
-
Silly what ifs aside the ECM looks pleasing to the eye but synoptically far from winter nirvana. I mean if the run is fantastic etc etc now, then where do we go if say in a few days time it was showing -12c 850's across the country for example.
-
More seasonal type weather on the way by the looks of things but a long way short still of anything resembling a potent cold spell just yet. Far better though than mild rainy mush. It would not take a lot, a tweak here and there to see more noteworthy colder uppers thrown into the mix though.
-
Would not be surprised that the heights and blocking being shown on the h500 charts are the results of the wave breaking towards the end of October over north America and Canada and subsequent weakening and split that followed in early November as seen below.
Just trying to make sense of where these heights and blocking being shown in the synoptic charts originated from. if this is indeed the case and I am pretty sure it is then it does not look as though their has been much if any disconnect between mid strat and trop after all. In fact it is just a lag effect as vortex weakening and split worked its way down and slowly starts to manifest itself in the trop charts.
-
12 minutes ago, bluearmy said:
Too much misery on here - I just checked my calendar ..........
too much stock being placed in long range output, extended ens data and volatile op runs - plus assumptions from strat data.
Couldn't agree more.
, but only a few experts. Tamara is very much one of the few and her posts are always worth paying attention to.
December 2017 C.E.T. forecasts -- start of 2017/18 competition year -- and an optional precip contest begins
in Spring Weather Discussion
Posted
Whoops was meant to do this a couple of days ago, 0.6c here.