Penellype's Weather Channel

[Penellype]

Confusion continues today - the first 2 runs of the GFS were mild, but the ECM and GEM models turn bitterly cold as early as Tuesday next week. This evening's GFS operational run has taken sides with the other 2 models, although the cold takes longer to arrive. The other members of the GFS ensemble are nowhere near convinced and some of them remain quite mild.

If the ECM and GEM are right we are in for a big freeze. This is not pleasant daytime temperatures and a couple of degrees of frost at night, it is daytime temperatures below freezing, possibly into minus double figures at night, and quite a lot of snow especially in the east.

I hope they are wrong, but it isn't looking great at the moment. Make the most of this weekend!

[Jungle Jane]

We had snow that settled in March a few years ago,I’d hired a bouncy castle for my daughters birthday party about six or seven years ago & I was worried the snow wasn’t going to go but it was ok in the end,sunshiny party

[geepee]

Confusion continues today - the first 2 runs of the GFS were mild, but the ECM and GEM models turn bitterly cold as early as Tuesday next week. This evening's GFS operational run has taken sides with the other 2 models, although the cold takes longer to arrive. The other members of the GFS ensemble are nowhere near convinced and some of them remain quite mild.

If the ECM and GEM are right we are in for a big freeze. This is not pleasant daytime temperatures and a couple of degrees of frost at night, it is daytime temperatures below freezing, possibly into minus double figures at night, and quite a lot of snow especially in the east.

I hope they are wrong, but it isn't looking great at the moment. Make the most of this weekend!

Do'nt like the sound of that Pen'

[Penellype]

Do'nt like the sound of that Pen'

Me neither. At the moment the operational (thick green line) continues to be one of the coldest runs, with several members still showing much warmer temperatures this morning:



The ECM and GEM models still have us cold or very cold by the end of next week. We will just have to wait and see, but I wouldn't be planting anything that isn't hardy just yet, even in an unheated greenhouse.

[Penellype]

Sorry to bring bad news but...

Unfortunately the GFS ensembles this morning are converging on an exceptionally cold solution, similar to the other models. This is the midnight run:



Note that the white ensemble mean line is being held UP to very cold levels by a few very warm outliers. Most of the runs are a good way below the mean. Many are 10 degrees or more below the red seasonal average. The operational run is one of the earliest to break out of the cold spell, and this can't be relied upon.

Be prepared for a long spell of very very very cold weather starting around next weekend with anything that falls from the sky being snow. It may not be that bad or that long, but some of those lines are unusually extreme and the weather patterns that they correspond to are not easily broken out of.

In the meantime we have a couple of warmer days and milder nights but there will be some light rain around. By mid week it becomes colder and drier with an increasing risk of frost and fog, and this trend continues.

Sorry

[Nicos]

Thanks for the warning Pen.

[Martin H]

The cold snap is showing up on Metcheck now. Here's next Monday round our way. If it pans out, it'll be the coldest day this winter I think. Brrr!

[unclefudgly]

Oh dear! I really thought we had seen the last of the cold weather. It looks horrible!

[Penellype]

The models are firming up on this now, and the various weather forecasters are using words like "notable" and "extreme". This has the potential to be really quite unusually cold - this morning's 6am GFS run would apparently be record breaking if it verifies. It has a week to change its mind, but somehow I think this is coming our way, the only questions are how extreme and for how long.

I can't answer either at the moment.

[Scoot]

And there was me hoping to get out into my greenhouse and sow some seeds at the start of March. Maybe not.

[Penellype]

I definitely advise waiting to see what happens. The currently forecast cold snap is being "blamed" on the sudden stratospheric warming that happened a few days ago. A 2nd warming is now taking place and I really have no idea what the effects of this will be.

This forecast cold spell is not a huge surprise, although the possible severity of it is. This winter started with several factors in place for it to be colder than recent winters have been (near solar minimum, La Nina and easterly QBO) and there have been repeated failed attempts to get the wind into the east. I've noticed from watching videos of the charts for past cold spells that you often find that the pattern has several tries before the cold finally arrives, and this has certainly been the case this year. There have been several times when I have thought that we were lucky to have got away with it. If it does pan out as the models suggest that it may we could be looking at a month or more of wintery conditions before things really warm up. I hope not.

[Penellype]

Quick update.

The cold weather is still on track to arrive at the beginning of next week. I can't put things any better than the excellent Liam Dutton did on Twitter last night:

"My latest thoughts on cold weather;
CERTAIN
- cold to end this week (highs 4-7C)
- very cold early next week (highs 0-3C)
- hard frosts (widely -5C)
- significant windchill
- increasing snow risk
UNCERTAIN
- longevity of most intense cold
- detail of how much snow and where"

Given the orientation of the cold air mass, the least cold places will be to the north and west of Scotland, the coldest in the south east of England.

[Thelma Sanders]

Yes, cold was 'nailed on' yesterday and I've started bringing indoors all the tender stuff from the greenhouse, that is in pots. Anything tender I can't move is getting fleeced or bubble-wrapped before the weekend.
All the supposedly hardy plants in pots are going into the greenhouse for some shelter.

This will certainly test how hardy the Winterkefe peas are, planted in the greenhouse beds and currently about a foot high

Good luck to everyone and their plants! Wrap yourselves and your plants up as well as you can..

[burnie]

We are already experiencing temps to -4 in Angus at low levels, minus 7 is the coldest I have recorded this winter so far.

[1Bee]

Thanks Penellype. Good luck everyone, see you on the other side...