[Model Output Discussion - cold spell to end Autumn]

Just now, feb1991blizzard said:

Absolute corker!

It is Indeed   shows aswell lower uppers on quite a few compared to the OPP    looking good   these are for Brum  so further south may also be in with a chance of the white stuff

[Model Output Discussion - cold spell to end Autumn]

much more support on the ensembles 

[Model Output Discussion - cold spell to end Autumn]

Ive seen worse means at 180

[Model Output Discussion - cold spell to end Autumn]

Nice run from the 6z   quite a few areas experiencing a rain to snow event   infact some places could get 2 days of snow   cold digging south all the way to North Africa  Bone chilling windchill   and with movement for upgrades  particularly on the snow and uppers.  All in all very good run.  and at least we seem to be getting a little consistancy within the models at short time frame.   lovely start to winter

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, Danny* said:

There does seem to be more clustering towards the colder side on the ensembles this evening, GFS/ECM show a cooling trend. I think we can probably agree we wont be getting any "deep cold" anytime soon. From what I've seen, it looks like briefly cold followed by briefly mild followed by cold again seems to be the way forward. Transient ridging Northwards in the Atlantic followed by a topple.

Not great for snow in the South, but the North could do quite well in the usual places.

Yes and the mean is around the -5 in some places. Those ensembles are for middle England  if that happens it should snow here. Not to much of a leap to get snow further south 

[Model Output Discussion - cold spell to end Autumn]

Full ensembles. No real use only posted to get post count up. But it does show chilly temps 

[Model Output Discussion - cold spell to end Autumn]

There's the northerly plunge  central England 

[Model Output Discussion - cold spell to end Autumn]

Control. Northerly picking up momentum on the ensembles 

[Model Output Discussion - cold spell to end Autumn]

Well there is your stormy December incapsulated in one run. The gfs has I believe 3 depressions near us  all three will give somewhere some snow as they swoop from the north of us. All in all a encouraging run. Will it be like that on the 0z ? Does Donald trump eat halal 

[Model Output Discussion - cold spell to end Autumn]

Way out but again snow for quite a swathe  of the country 

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, I remember Atlantic 252 said:

606 ish hours until Xmas, a horrid one too

Quality post. The models are unsure what happend an hour ago never mind Christmas  but of course if it was showing a white Christmas  that would be a different matter .   Anyway 18z due I expect an upgrade  keeping an eye out for shortwave movement

[Model Output Discussion - cold spell to end Autumn]

2 minutes ago, nick sussex said:

I'm still waiting for the NOAA updated monthly forecast but in the meantime the New York state forecast calls into question the outputs which remove the Greenland block too quickly.

It's a long read but well worth it.

Looking farther ahead, the major pattern change that starts to take
shape Wednesday will mature by the end of next week. Long range
ensemble guidance is an excellent agreement with this pattern
change, and has only grown stronger with forecast blocking over the
past few days. The anomalously strong and eastward extending East
Asian Jet is in the process of weakening, and this will allow for a
strong amplification of the Pacific wave train. This will force the
downstream pattern across North America to strongly amplify, with a
strengthening ridge along the west coast and a deep longwave trough
carving out over central and eastern North America. At the same
time, blocking over Greenland will strengthen.

The increasing high latitude blocking will project on an
increasingly strong negative AO (Arctic Oscillation), with the
Greenland Block forcing a negative NAO (North Atlantic Oscillation).
The western ridge/eastern trough and amplification farther west in
the Pacific will force an increasingly positive PNA (Pacific North
American) pattern.

The coupling of a negative NAO and positive PNA pattern will result
in an extended period of below normal temperatures and active winter
weather for the Great Lakes starting late next week, and lasting for
an extended period of time. The first few days of the pattern change
late next week will be routine cold, but after about December 10th
there are increasing signals in long range ensemble guidance that
several blasts of true arctic air may be in play for the Great Lakes
and Northeast. Obviously details are impossible to predict at this
time range, but the large scale pattern suggests the possibility of
numerous high impact lake effect snow events starting late next week
or next weekend, and continuing through the middle of December. Stay
tuned.
 

The upstream pattern is really one that should help downstream for UK coldies, the fact they mention an extended period of time is good. Of course energy being thrown east into the Atlantic will run towards the UK but it should be angled more favourably.

The displaced Azores high would be as a result of that upstream amplitude in the east USA with that troughing.
 

The update sounds very good however it mentions a Greenland block  we have seen hints of this mainly from the gfs  but if this is correct this should start to show its hand more frequently   Still very much up in the air 

[Model Output Discussion - cold spell to end Autumn]

4 minutes ago, nick sussex said:

I tend to think of the north as anywhere from the Peak District northwards.

 

Yes I reckon there is a door by derby one side people drink pimms and play polo  the other side people breed whippets and point at the moon in wonder  anyway has the t168 ukmo been issued yet hopefully that will be an improvement on the ecm 

[Model Output Discussion - cold spell to end Autumn]

While we are between runs may I ask we're is the north. I hear this expression a lot on met office website and BBC reports i.e. "Snow in the north"  rain in the south. Would you think it's a line through the country  or is it the BBC rule and anything to the north of Watford is classed as the north  I wish someone would put a definitive line on we're the divide  is 

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, jvenge said:

Well. Im too tired to wait the control and EPS. Ill check the 0z tomorrow instead. Something tells me the 18z will be eagerly awaited here tonight.

 

In all seriousness for me it's still up in the air  as nick alluded to the shortwave and how it behaves dictates were the run goes     96 is were the models deviate  I expect it will be resolved by 12z Friday night   But your right ecm usually handles this situation better at this timeframe  we shall see 

[Model Output Discussion - cold spell to end Autumn]

3 minutes ago, jvenge said:

You don't like Uncle Bartlett? Sure, he drinks a lot and starts fights, but a decent guy.

Anyway. There is only one member of the GEFS showing anything like that. Can almost the ENTIRE GEFS be that wrong?

It is a brave man to bet against the ECM at t120 though.

True it is a brave man. But it's 120 chart from the 0z is different to the 12z. Conclusion ?  It's hasn't a scooby . Pretty much like the rest of us. Confused and disoriented 

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, I remember Atlantic 252 said:

Know which one I prefer! ecm obvious, could even be dry altogether on ECM

Got a feeling it will end up nothing like those two examples. Just call it a hunch 

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, karlos1983 said:

separately, Worth noting the Icon slammed the Tropical Cyclone straight into the Philippines on it's earlier run, whereas the GFS takes it straight out into the Pacific south of Japan. 

Anyone know how well this model performs? or is it just a gap filler whilst we wait for the big dogs to roll out.

To be Honest  I really have no idea  took no notice until a few days ago.   Update its more amplified  than its last run!  i expect its on par with the Bom etc

[Model Output Discussion - cold spell to end Autumn]

2 minutes ago, Ed Stone said:

Right then, it's that time again...

Will our trend-friendly GFS12Z finally deliver the goods? Or will winter be put on-hold for the umpteenth time-being?

I think we might like to see an Arctic blast at around T+120ish. Anywho - here's hoping...

Prozac on standby...

Yep  Pete eyes down lets see the trend from the 6z continue on the 12z.    im also keeping an eye on the ICON rolling out now.  The Icon!  times really are desperate. 

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, Frosty. said:

It does sound a bit cr*p for the south unfortunately as things stand. Perhaps becoming colder at times further north.

It's the very uncertain after Tuesday that's the tell for me. A few days yet I expect before all is settled 

[Model Output Discussion - cold spell to end Autumn]

Hopefully mods will keep this here. But it's a response from fergie answering my previous tweet  looks very uncertain next week 

Replying to @weirpig and @modernwinter

Yes, GFS has been v volatile lately (=again). There's a more pronounced leaning in 00z EC EPS towards Atlantic mobility/cyclonicity increasing, *but* cold phases still likely at times and all in all, a v uncertain medium range prognosis post-Tues, let alone further out.

[Model Output Discussion - cold spell to end Autumn]

Just now, SLEETY said:

why what did he say

 

some places will be digging themselves out of snow IF this gfs run comes close to verifying.Can it just once 

Just asking when the Met will be updating there forecast    And fergie replied why.

[Model Output Discussion - cold spell to end Autumn]

Another 6 hours  another outcome  just set back and enjoy   I bet Ian brown wished he hadnt started Trolling Ian ferguson now.

[Model Output Discussion - cold spell to end Autumn]

Difference again on the GFS   whwere will this take us

[Model Output Discussion - cold spell to end Autumn]

1 minute ago, ShortWaveHell said:

Well the ECM put a double or nothing knife edge bet on at 168 and cleared its bank account .. now into days 8-9 it’s re mortgaged the house and now the bailiffs have arrived in a daffodil filled garden ! 

Absolute quality. Cheers for that