Model Output Discussion - What does April have in store?

[Frosty.]

2 minutes ago, Ed Stone said:

And, were that big Atlantic depression (always assuming that it'll even exist!) not to misbehave, we might even see uppers of 15C reach our shores? High 20s?

 

We must also keep that giant-sized blue whale in its enclosure!

It's the Ed and Frosty show today..are you not entertained!!!

[Methuselah]

FV3 backing-off a tad, for Saturday's possible snow? Just as I was coming around to the idea, too!

 

[MATTWOLVES 3]

Nothing to exciting in the next few days gents, on a positive note I've just ordered my snow making machine for the weekend!

[Frosty.]

The 6z parallel shows high pressure for Easter and just look at that heat building to the south. It's insane!!!!!!

Edited April 9, 2019 by Frosty.

[Methuselah]

Just now, Frosty. said:

The 6z parallel shows high pressure for Easter and just look at that heat building to the south. It's insane!!!!!!

It's like swollen pustule just about to burst...Just where on the mirror will the pus end-up!

[stodge]

Afternoon all

A lot of uncertainty in the medium to longer term, I'd argue, from the models this morning. The question is how do you keep the E'ly going? Basically, two approaches - one is to maintain northern blocking by keeping the HP over Scandinavia or hint at some form of retrogression. The second is to expand and develop the trough north toward the British Isles which maintains an E'ly flow even if heights are absent further north. 

I'm far from convinced a return to warmth is going to mean a return to settled conditions for all though I do think the north and north west (as they often do at this time of year) will do well. Further south and south west, the risk of thundery showers coming up from the south is present as well as more prolonged and heavy rain if the Atlantic LP tries to approach. 

As for the PV and the strat playing their part, the zonal winds are forecast to return to a more normal speed having been very high for late in the season and it may well be the speed of the wind drop is exacerbating blocking tendencies but if we get a wave 1 warming it would only re-strengthen the PV on the Canadian side and force a return of Atlantic conditions into May.

[shaky]

48 minutes ago, Ed Stone said:

FV3 backing-off a tad, for Saturday's possible snow? Just as I was coming around to the idea, too!

 

Dont worry it will upgrade and push further west on the 12z!!

[Frosty.]

Looking at the 6z operational, saturday would be our last opportunity for snow..it's been a hell of a ride hasn't it..not!!

Edited April 9, 2019 by Frosty.

[Methuselah]

As someone suggested a while back (Mike Poole?) we could, at some point in the not-too-distant future, witness something of a battleground? If, of course, the burgeoning heat in Europe clashes with a dying ember of Arctic air...all Hell could break loose?

 

[Frosty.]

Looking at the GEFS 6z mean, the period covering Easter indicates a very slack pressure field which could be filled by an anticyclone as some of these perturbations show..so, although nowhere near certain, there's a fighting chance that the upcoming holiday could be rather pleasant for many.

[Frosty.]

P6 is lovely..it would make a perfect template for the upcoming summer!!

[Methuselah]

6 minutes ago, Frosty. said:

P6 is lovely..it would make a perfect template for the upcoming summer!!

A summer of heat (that, like last-year, lasts long enough for one to acclimatise) and -- unlike last-year -- gives us plenty of storms...? Something similar to either 1975 or 1983 would do nicely. Very nicely!

[knocker]

It's actually been a pretty good day down here. A fair amount of Cu but plenty of sunshine but looking grotty to the north east

[Frosty.]

Following the upcoming colder interlude there are good signs that temperatures will make a full recovery with even some warm potential both for easter and beyond along with high pressure.

[Don]

2 hours ago, Frosty. said:

Following the upcoming colder interlude there are good signs that temperatures will make a full recovery with even some warm potential both for easter and beyond along with high pressure.

Yes, the heat looks like it will be ready to pounce soon.  Not what I want that’s the way it is now.

Edited April 9, 2019 by DiagonalRedLine
Terminated the quoted charts to save some page space

[Frosty.]

6 minutes ago, Don said:

Yes, the heat looks like it will be ready to pounce soon.

Hi don, hopefully but could you edit out the charts as I've already posted them, just trying to save some page space..ta

Edited April 9, 2019 by Frosty.

[Methuselah]

Cold still inbound...But is the SST-850hPa temperature gradient going to be sufficient for anything other than rather feeble convection -- and given the fact that SLP is gonna be quite high...?

Edited April 9, 2019 by Ed Stone

[Frosty.]

The ukmo 12h is not backing down with the strengthening easterly so becoming colder is the theme but notice by T+144 hours a subtle shift in wind direction more south of east with the chill starting to ease which would likely accelerate beyond day 6..so, colder weather on the way, accentuated by the strength of the Easterly winds, the increasing risk of a few showers, mainly further east which could become wintry for a time, especially on saturday, some sunshine, especially further west and overnight frosts where skies clear.

Edited April 9, 2019 by Frosty.

[Methuselah]

If that painful-looking red swelling, down south, carries on growing, Mr GFS might need to make an appointment with his GP? That'll be for October then!

[Methuselah]

Oh no! Not again! 

And at the end of the run, the hot-pool is even more intense:

                              

Edited April 9, 2019 by Ed Stone

[Frosty.]

7 minutes ago, Ed Stone said:

Oh no! Not again! 

Considerably more potent than what's soon coming from the east..

[MATTWOLVES 3]

Far to much talk of heat plumes today! Let's line up another cold shot courtesy of our good old friend MR GFS!

Wow, check the cold pool to our North, you would think it was January.... 

Edited April 9, 2019 by Mattwolves

[Mike Poole]

As the models firm up on the colder weather towards the end of the week, it seems clear that some cold uppers will encroach from the east, maybe the current runs slightly less cold than selected runs from the last day or two.  However, what is increasingly clear is that this will be in the context of high pressure over most of the country, here for example GFS 12z T96:

So there really isn't going to be any appreciable snow from this, at this time of year you would need some instability in the flow, heavy precipitation, evaporative cooling to deliver any significant snow.  

So on to the next story, the potential flip to heat, the reds to the south need watching here, GFS T240:

 

[Methuselah]

While the remnants of cold air erratically fade away, that heat-pool just gets both bigger and more intense...I fear for folks living in Southern Europe, come summer proper.

From the 12Z ensemble, the GFS Op (unless it's found a new trend!) goes a tad doolally after the 21st:

[Frosty.]

My goodness there are some stonking summery charts on the GEFS 12z for late April!.. Sad smiley alert!