Jump to content
Sign in to follow this  
Paul

Model output discussion - proper cold spell inbound?

Recommended Posts

Sticking to the models, both ECM and GFS show a similiar scenario as we move into mid February, a slowly sinking trough aligned WNW-ESE, spawned from the PV, a pattern we have seen predominate all winter in the main, with the azores high languishing to the SW unable to exert its influence. End result very cold uppers continue to spill into the N Atlantic, sub 522 da air easily enveloping much of the UK at times, Friday and Sunday for example and at times next week, wintry precipitation for the NW, generally cold, with only fleeting milder interludes, tomorrow and Saturday.

Longer terms, signs the trough will detach itself from weakening PV, and allow for mid atlantic height ridges, which could then merge with strong heights ridging out of Russia - this is definately the most plausible root to high lattitude blocking should the effects of SSW result in a favourable outcome for cold spilling our way. Our cold spells often come courtesy of the azores high ridging north through the mid atlantic, shutting off the atlantic and then advancing to the NE. The Greenland high often comes later through retrogression.

Share this post


Link to post
Share on other sites

The ecm t240 chart going the way I have anticipated but of course it could  be completely different tomorrow. You can sense the expectations in this and the strat thread for what may lay  ahead. Over the next four weeks we could possibly see some of the best synoptics  and winter weather that could match any of the UK's past freeze ups. I know I have not held back with my expectations from the major strat warming and subsequent teleconnects but our locale (uk and Europe) looks to be in prime position to reap the rewards from this, both from a easterly and northerly quadrant.

Share this post


Link to post
Share on other sites

Think the models are going to get better and better as they increasingly start with lower and lower zonal winds already factored in. Mean winds at 60N are already down to about 25m/s today.

Edited by Snowy L

Share this post


Link to post
Share on other sites

Who remembers the days when it tended to be GFS making dartboard lows and leaving us shaking our heads while ECM went head-over-heels in for disrupting and sliding lows?

How far we've come shaken things up :laugh:.

Either way we do look to be headed down the same broad road, it's just that the deeper the trough, the longer the hill to climb (but only by a day or two).

Edited by Singularity

Share this post


Link to post
Share on other sites

Obviously GFS precip charts aren't the most reliable, but based on this there could be a few snowy surprises around on Sunday evening.  -8's over pretty much the whole country at 96....one to keep an eye on.  And this is before we get to the main event (hopefully!)

gfs-2-96.png?18 gfs-1-96.png?18

Share this post


Link to post
Share on other sites

As the mother pv-lobe will weaken...so the pac- ridge will become the daddy .

Notable flexing run-2 run now.. with russian pen form.. waiting to greet for the split..waving action occuring..and data signals evolving...

Not a wonder as we continue warm and waves.....

@ for note 10 hpa...

#ssw

gfsnh-0-90.png

gfsnh-10-96.png

Edited by tight isobar

Share this post


Link to post
Share on other sites

Cant see any sign of a Scandi block developing on GFS12 or ECM 12 op.

Share this post


Link to post
Share on other sites
3 minutes ago, Ice Day said:

Obviously GFS precip charts aren't the most reliable, but based on this there could be a few snowy surprises around on Sunday evening.  -8's over pretty much the whole country at 96....one to keep an eye on.  And this is before we get to the main event (hopefully!)

gfs-2-96.png?18 gfs-1-96.png?18

Ay, not often a westerly modelled as chilly as this

hgt500-1000.png

Share this post


Link to post
Share on other sites
3 minutes ago, I remember Atlantic 252 said:

Ay, not often a westerly modelled as chilly as this

hgt500-1000.png

Will minus 8 be enough  for snow though..it wasn't with the northwesterly the other week.

Edited by chicken soup

Share this post


Link to post
Share on other sites
6 minutes ago, - 40*C said:

Cant see any sign of a Scandi block developing on GFS12 or ECM 12 op.

Slp was 1030mb + post T192on the 12z gfs so there was a scandi high throughout. The upper ridge only showing at the very end week 2. it could well take 2 weeks, it may be quicker. WE DONT KNOW YET! 

Share this post


Link to post
Share on other sites
1 minute ago, chicken soup said:

Will minus 8 be enough  for snow though..it wasn't with the northwesterly the other week.

Yes, if trough feature as Midlands saw on the evening of 13th Dec, bringing heavy snow off a W'ly, no if convective

 

gfs-2017121312-1-6.pnggfs-2017121312-0-6.png

Share this post


Link to post
Share on other sites

Lows hitting the wall at t135. GFS is getting things done far earlier than ECM. Could it be because its showing a much bigger reversal than ECM?

 

Edited by Snowy L

Share this post


Link to post
Share on other sites
4 minutes ago, Ice Day said:

Obviously GFS precip charts aren't the most reliable, but based on this there could be a few snowy surprises around on Sunday evening.  -8's over pretty much the whole country at 96....one to keep an eye on.  And this is before we get to the main event (hopefully!)

Yes Sunday looks very interesting. Looks like western Scotland will be hammered again with heavy snow showers. 

The upcoming SSW is very exciting, lots of potential for deep cold and snow over the next few weeks :)

Share this post


Link to post
Share on other sites
4 minutes ago, bluearmy said:

Slp was 1030mb + post T192on the 12z gfs so there was a scandi high throughout. The upper ridge only showing at the very end week 2. it could well take 2 weeks, it may be quicker. WE DONT KNOW YET! 

The models certainly don't know yet :)

Share this post


Link to post
Share on other sites

Well that would be interesting...Far too early to look at in detail though.

144-515UK.GIF?07-18144-779UK.GIF?07-18

Share this post


Link to post
Share on other sites

Oh beast from the east, why so shy again? You've just had your nuts warmed up. Time to move west! 

Share this post


Link to post
Share on other sites

Watching that monster low south of Greenland actually travel westwards in the later frames of high res is so wierd. Call me a weather nerd but it feels like everything is upside down watching those frames! 

Share this post


Link to post
Share on other sites

The pub run seems to be caught in two minds. A little like it is wondering to have that extra pint or just call it a day :)

Share this post


Link to post
Share on other sites

Looking through the gefs from the 12z gave me the impression that the model (probably not just this one) was clueless what to do later next week. No surprise to see this op run on a different tack in the mid term.

Share this post


Link to post
Share on other sites
1 minute ago, bluearmy said:

Looking through the gefs from the 12z gave me the impression that the model (probably not just this one) was clueless what to do later next week. No surprise to see this op run on a different tack in the mid term.

It does seem to move closer to the ecm 12z op in the 6 to 8 day range though. 

Share this post


Link to post
Share on other sites

Gfs 18z begins  N-HEMISPHERCALY to look messy and ugly...

Thise are great signs...wouldnt you- if your were about to go through a metamorphisis...but in reverse state!??..

Mjo into phase 8 border..and the noted 10hpa bunsen burners..are throwing data into dissaray...and a clean evolution wouldnt be feasible.....

Ssw of big proportions coming at us!!!!

By week end runs and supports should start the clean up...

Share this post


Link to post
Share on other sites

So the first strat warming peaks around 132 then at 234 the second warming gives us this.  These certainly feel like extremely rare synoptics, is it any wonder the models are all over the place at the moment!

gfsnh-10-228.png?18

Very cold pool of air to the north east inching its way towards us at 240

gfsnh-1-240.png?18 gfs-1-240.png?18

Share this post


Link to post
Share on other sites

Aaaaaaand! Yes, the pub run went for the extra pint and ended up with brewers droop! 

Edited by blizzard81

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×
×
  • Create New...