Model output discussion - mid January

[feb1991blizzard]

6 minutes ago, Steve Murr said:

ECM similar but quite progressive @192

I'm wondering re - Ians tweet about timing middle of next week - that's D10-11 ish, if this isn't going to actually be the Easterly the EPS are going for, maybe this next ridge ridging up towards E Canada / Greenland will be the one that does the trick, id rather  that as even the best case of the E'ly 168-192 (ish) might cut off the low heights / 850's too quick and you might only even get a dusting and everywhere Watford North just cold and dry perhaps.

Edited January 28, 2018 by feb1991blizzard

[SMU]

JMA 192 shows the -10c line well into the UK but the cold is totally overshadowed by the depth of the cold over Canada etc-

[comet]

1 hour ago, Chris101 said:

The only place i've seen any consistency in the Gfs over the last couple of days is in the 18's, the rest have been as others have said, all over the place.

I know they have been very cold runs, but a usual watered down version would still bring the goods, i do like it when Gfs shows really deep uppers early on, it gives a bit of play.

Anyway, i shall have a keen eye on tonights 18z and hope they have some resemblence to the last couple.

The ECM operational has been just as bad as gfs imo no consistency at all, and tonights run looks no better.

[feb1991blizzard]

Awful ECM ending - lets hope its an outlier.

[Daniel*]

2 minutes ago, feb1991blizzard said:

Awful ECM ending - lets hope its an outlier.

It’s not awful MLB right over British Isles appears another go at it would be possible. 

[comet]

1 hour ago, jvenge said:

Begs the question....

Who would actually want one mid feb? 

A proper beast would deliver the coldest uppers and surface cold although that may not necessarily be true for Scotland.

[nick sussex]

6 minutes ago, feb1991blizzard said:

Awful ECM ending - lets hope its an outlier.

You’re becoming more melodramatic than me ! 

Low pressure over Southern Europe at T240 hrs and the high isn’t going to sink, suggestions of some retrogression so yes frustrating that any ne is cut short but more runs needed , yes predictable I know! 

 

[Daniel*]

A little bubble of -40C uppers on the border on GFS 12z as far as I know that’s unprecedented. Looks like some historic cold regardless over there, it doesn’t help us with it spilling off eastern seaboard.. 

[Duane S.]

The writing was on the wall early on the ECM. As per my post a couple of days back. 2 (initial) routes, no change. Now down to just 7 days away.

GFS takes route #1 with that energy ejected from the vortex taking a different track and allowing that small but crucial ridging to slip in behind it. From there we have every opportunity to drag in CAA towards us a few days later.

ECM takes route2, no quick Easterly with this route.

There is no winter game over scenario though. We might have to accept the ECM may be the more likely but plenty more opportunities to come as Feb gets up and going.

[bobbydog]

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

4 minutes ago, Daniel* said:

A little bubble of -40C uppers on the border on GFS 12z as far as I know that’s unprecedented. Looks like some historic cold regardless over there, it doesn’t help us with it spilling off eastern seaboard.. 

Funny to think that Cornwall is further north than that - 40 air

[Sneachtastorm]

32 minutes ago, Steve Murr said:

11c ish -

ECM / UKMO broadly similar with a more aggressive low pressure around 144-168 taking a slightly different direction to the GFS I highlighted - although depending on the rushing could be similar by 192-

S

Is 11c a general rule? Is there a difference between North and South or pretty similar? 

[Daniel*]

7 minutes ago, Sneachtastorm said:

Is 11c a general rule? Is there a difference between North and South or pretty similar? 

No it’s not a general rule yes there very much is, I think +11C maybe more would be most applicable to the surface temp if it’s from the N/W. It does fluctuate a lot dependant on where airmass is from, with continental cold a fair bit lower. You could have -5C uppers from the E and be just above freezing midwinter, there’s lots of factors involved how cold the continent is, whether it’s snow covered a short sea track, & the time of year. Generally I think with continental cold it’s about +8C in middle winter.

Edited January 28, 2018 by Daniel*

[SMU]

10 minutes ago, Sneachtastorm said:

Is 11c a general rule? Is there a difference between North and South or pretty similar? 

It’s a generalised number for Easterly sourced air ~ +11c off a sea track maybe +9c if straight off the continent

of course final daytime Max will be certainly different if you have constant cloud cover & snow flurries V somewhere with full sun- However at this time of year in -12c air then surface maxima won’t get much above 0c across the piste- major cities like London would add a +2c but equally out in the countryside maxes could be surpressed to -2c

Anyway we need the euros on board for weaker low pressure to the NE first!

Edited January 28, 2018 by Steve Murr

[Daniel*]

10 minutes ago, RAIN RAIN RAIN said:

Funny to think that Cornwall is further north than that - 40 air

It’s quite sad isn’t it the joys of being an island surrounded by large expanses of water.

[bluearmy]

19 minutes ago, Daniel* said:

A little bubble of -40C uppers on the border on GFS 12z as far as I know that’s unprecedented. Looks like some historic cold regardless over there, it doesn’t help us with it spilling off eastern seaboard.. 

It’s not just the depth of the uppers but the gradient to the south of it that dictates the strength of the jet. I reckon if that cold stays bottled up over Canada then the jet strength is not the problem re amplification. 

Which bite of the cherry is going to bring the cold ??

[Summer Sun]

UKMO extended once again going for a cooler flow at t168

[karlos1983]

MJO watch

ECM- 

[Daniel*]

17 minutes ago, bluearmy said:

It’s not just the depth of the uppers but the gradient to the south of it that dictates the strength of the jet. I reckon if that cold stays bottled up over Canada then the jet strength is not the problem re amplification. 

Which bite of the cherry is going to bring the cold ??

That is true it wouldn’t achieve anything if there was not a big gradient and having a look at its worst there isn’t really a notable one spaced out I’ve seen much worse the extreme cold stays largely on land.

 

Edited January 28, 2018 by Daniel*

[Scandinavian High.]

Trend much colder weather looking very interesting now BBC also hinted at cold easterly it's just a chance at the minute lets  hope everything falls in to place nicely..

[Dennis]

6 minutes ago, karlos1983 said:

MJO watch

ECM- 

its needs more "power" - GFS has - but positions make or break

[offerman]

34 minutes ago, RAIN RAIN RAIN said:

Funny to think that Cornwall is further north than that - 40 air

Excellent post. And thats what i just cant understand . They dont seem to have an equivalent of an azores high that permanently buggers up their winters. Winter after winter now in the US seems to be so frigid ......

Until the azores high retreats south or far west to allow northerlies incursion or to drift up and above us i just cant see how any cold can develop. once again all the recent euphoria has yet again been nullified. 

 

Just ignore these longer range charts and you'll now be disappointed, i know as i used to do the same as so many on here and took too much notice of all the blue deep cold in F! that so so so rarely panned out. Wait until better verification nearer in... 3-4 days and even then that can still swing wildly .....  

[ArHu3]

25 minutes ago, Daniel* said:

It’s quite sad isn’t it the joys of being an island surrounded by large expanses of water.

If it is any consolation the weather sucks on the mainland too

[Norrance]

53 minutes ago, comet said:

A proper beast would deliver the coldest uppers and surface cold although that may not necessarily be true for Scotland.

Why not?

[MP-R]

Just now, Norrance said:

Why not?

Scotland would be more affected by higher pressure and less of an easterly flow, perhaps even a wrap-around within the high's circulation. A beast from the east in Scotland would most likely be a southeasterly or southwesterly in the south.

Can anyone think of examples of a proper easterly affecting the entire length of the UK?