Interesting. 

As for the ash. I will not effect weather at this latitude, if at all, for a long time.  It could take months for it to reach our latitude.

Just in time to ruin summer 

 

 

Just in time to ruin summer 

..Well we were due another good summer. That cannot be allowed to stand 

The 12z GEFS t850 ensemble mean dips to -11.4°C on Wednesday night here (and I’m not sure it will be evident as anything other than feeling a bit chilly due to the proximity of high pressure).

You might scrape a frost out of that 😂 Rather chilly, I would like to have that down here please . Maybe in early feb instead 👍

Martin

Just notice the GFS Ensemble 850 uppers are trending colder at day 5/6 (makes a change!) Notice a dip in the upper air temperatures. For instance focus on midday on 20th January 12pm:

Starting from this mornings 06z run: - ENS mean of -2.1c

 

This evenings 12z run - ENS mean of -4.0c:

 

Tonight's 18z run: - ENS Mean of -6.4c 

On tonight's 18z there isn't one Ensemble run reaching 850hpa long term mean let alone going above it.

Is something colder brewing in the medium range or am I being too optimistic? ENS rarely trend colder in winter so perhaps we could be in for a surprise but not holding my breath after all the let downs so far this winter esp in December over Christmas time when many models were showing an easterly with snow a few days before and then that record breaking warm NYE/NYD.

What is certain is that some of the runs - esp the Operational are taking the HP further west each run allowing colder air masses in from the north and east...! BUT will this trend continue? Fingers crossed!?

Looing at the Ensembles the 850 ENS mean for London for 20th January at midday is now down to -7.6c.

Interesting that GFS is MUCH colder for Thursday than ICON, ECM, UKMO etc... opening the door to much more of a northerly blast.

Been a crazy winter of uncertainty at relatively short timescales, nevermind extended or FI lol!

Hi Gavin

I made a very similar point in this thread during the week just gone. It has seemed more often than not recently that output for what is normally considered to be the more reliable timeframe has been open to question and subject to change. Even the very mild spell over New Year did not last for as long as the models had originally indicated it might last for.

 

Looking at the Ensembles the 850 ENS mean for London for 20th January at midday is now down to -7.6c.

The 18z 850s Ensemble mean for London for 20th January at midday is now down to -8.2c.

Upgrades in the shorter timeframe could be the way forward? 🤔 

A sobering bore-fest morning GFS Op, after a great night out at the pub (run)...brings the Atlantic back in FI after a northern jet shoot-out. We may get a cold blast down the east coast, but this is only a flirt from other models and blink and its gone, before the fat toppled high squishes it and pushes it in to Eastern Europe. 

Summary charts like yeterday and the day before, cold air across N Europe and separately across the Alps,not as cold in between more emphasis on S branch today. pptn N Atlantic and in the Med

GFS 0z - HP over or close to Uk for rest of Jan, occasional Nly plunges just missing E coast eg Thu 20th Sun 30th; zonal W-lies for start of Feb

GEFS - agreement on brief cold spell Thu 20th, mean soon reverts to norm and later on a little below, not much agreement between ens members after Thu 27th (significant number of colder members in the mix) Very dry, a bit of rain Feb 1st/2nd

ECM -  Like GFS but Hp somewhat further S from Min 24th with more W-ly influence

If anyone is looking to see an interesting chart this morning the CFS is looking good for February. Builds a strong scandi high with a low over Europe.

 The hair of the dog for the cold weather fan.

 

 The hair of the dog for the cold weather fan.

We can normally find the odd decent chart in the GEFS even in meagre winters like this one, but when these are in short supply the CFS expended range at 1000hrs + can provide some entertainment.

As Lord Sugar might say, the hunt for a snowflake this winter in deepest, mildest low-lying Hampshire continues.

 

 The hair of the dog for the cold weather fan.

most definitely 😂😂