Could there be rain in UK later next week?

[Julian Mayes]

I don't want to tempt fate and scupper the weather's plans, if it has plans, but GFS does get a bit excited (00h deterministic run) about rain from midweek next week (some from France meeting showery rain in a N'ly that eventually takes over by late next week). Both models and MO global show a drop in pressure over France by Weds. 

EC more reserved with pptn then, tending only to bring the showery rain with the N'ly, hence a longer dry spell implied. Of course at this stage neither may happen. 

The arrival of northerlies in last month or so has usually become swamped by high pressure extending from NW to kill off any cold front, at least for us in the south. 

Julian 

Molesey  

 (amusing to see that GFS is a suggested tag but ECMWF isn't).  

[Len]

Yes Julian. The atmosphere has at last responded to the easing of lockdown. We can meet up only outdoors and with umbrellas.

ECMWF High Resolution Model, (9km grid). give this for Plymouth at the end of next week:

[Julian Mayes]

Quick update / comment. GFS has fallen a bit into line with EC now and stifling the movement of any hvy showers moving into the south of the UK from France on Weds, though EC and GFS show fairly widespread showers from France to Germany. 

Us in SE will have to wait for some light showers to come south with the cooler airstream; EC puts most of any frontal pptn on Weds to central and western districts, though guess this may change by the time it actually approaches. 

So it looks like a gentle return to more unsettled weather - an EC shows some degree of ridging affecting the N flow later next week too. 

As Tudor said, once upon a time we used to get thunderstorms from the south......oddly, we now get more southerly airstreams overall than in decades past, though this was partly due to a backing of WSW airflows in unsettled zonal weather situations. 

Julian   

[Tudor Hughes]

As a corollary of this  it seems to me that the thunderiest part of the UK at least in summer is no longer the SE but the area has moved north and is more diffuse.  I wonder if recent statistics back this up.

Tudor Hughes, Warlingham, NE Surrey, 557 ft, 170 m. 

   

[Julian Mayes]

Yes Tudor - IIRC Bob Prichard wrote about this in an issue of COL some months ago (or was it elsewhere - but it was surely Bob). 

It should be well established in the data and where better to look but COL. 

I have a pet theory that the thunder totals have held up best in Lincolnshire. Why?  Just off the top of my head but if we have more SW flows in summer half year (i.e. not W'ly) then there's the issue of convergence with the sea breeze on fine afternoons.  SE England too near to high pressure areas to the south-east. I think we all know we don't get the southerly Spanish plume events - not in the SE anyway. 

There's a journal paper that tries to look at thunder frequencies in the official network. 

https://rmets.onlinelibrary.wiley.com/doi/10.1002/gdj3.75

....they found a decline over time. However, it was pointed out by Stephen Burt (who became one of the authors) that this was partly an artefact of the reduced staffing of such stations, hence my point about the value of consistent COL sites with vigilant observers. BTW, the Geoscience Data Journal, publ by RMetS is well worth browsing (via link above), not least because all papers are open access. 

Julian  

Thunder-free Molesey   

[Graham Easterling]

Thunderstorms here are often of a rather different variety to those in the SE. Many are the 2 or 3 flashes associated with showers drifting off the 'warm' sea in Autumn early Winter in an unstable mP airstream. But still a reduction in the total number of storms.

1991-2000 3 years with => 10 storms

2001-2010 2 years with => 10 storms

2001-2020 0 years with => 10 storms

Combined with the reduction in the number of gales, quieter times weather wise.

Graham

Penzance