Ben Sainsbury

ConvectiveWeather: Day 2 Convective Outlook VALID 06:00 UTC Sat 27 Aug 2016 - 05:59 UTC Sun 28 Aug 2016 ISSUED 22:13 UTC Fri 26 Aug 2016 ISSUED BY: Dan This particular plume destabilisation event carries an unusual amount of uncertainty, even at this short range. Below is the most likely forecast evolution based on guidance at the time of issuance - it is certainly possible some aspect will change with time, and we may not be able to update as this is a voluntary service. Elevated convection is expected to be ongoing with isolated to widely-scattered thunderstorms (albeit with not much precipitation reaching the surface initially) across parts of the south Midlands, East Anglia and southern England at the beginning of this forecast period, through isentropic upglide as the warm front lifts slowly northwards across England and Wales. This process is expected to continue during Saturday, with thunderstorm coverage (or at least showery precipitation) expanding through the day, mostly across the southeastern half of England - although even here some areas are likely to remain void of precipitation/thunderstorms (taking a theme amongst most NWP output would suggest parts of E Kent up into Suffolk and E Essex are least likely to see thunderstorm activity - but models should never be relied upon to that level of precision, hence are still included in the SLGT). PWAT values in the high 30s or low 40s mm brings the risk of localised flash flooding issues. MDT has been issued where the best overlap between numerous models suggest thunderstorms may develop - although this zone could be shifted to the NW. Along and south of the SW-NE orientated warm front, environmental conditions will be favourable for severe convection should any storms become rooted in the boundary layer. If this were to occur, then large hail to 3.0cm in diameter and possibly a tornado would be possible, especially close to the frontal boundary where low-level convergence will be maximized. This places the risk of severe convection greatest in a corridor from SE Wales / W Country / Cen S England NE-wards across the S + E Midlands to East Anglia. Extensive cloud may inhibit this potential to a certain extent. Through the evening hours, the approaching Atlantic upper trough will serve to increase convection coverage across N Wales initially, this also extending across northern England. Given the two zones with greatest potential (the MDT and this second zone through the evening hours), this then may leave a corridor of relative low activity from C + E Wales through the N + W Midlands - not to be taken literally, but emphasizing that some parts of the SLGT are likely to remain lightning-free.

12z on GFS actually looks perfect for my location, just a pity I have work...

Is that really a wild lightning strike in an unusual habitat nr Exeter? Dont believe it.

I don't know why but looks like a possible supercell to me?

Very quite true, I've been eavesdropping!

According to the Netwx SR, we should expect to see storms forming in Central Areas around 5pm.

My area of interest right now... With risk transfering eastwards as we move through day and become active with lightning and more severe.

And here is my take on today...

All lightning today so far...

I can certainly confirm your observations , I just reckon we'll see some weaker convective rain this evening, hopefully we'll see things pep up tonight.

Not to excite but some decent ML Cape around, 40kts of DLS and 350m^2s^2, I'm seeing a potential for organised and potential elevated supercells? Especially Multi-cells!

Gone very dark here and radar shows some intense -ish rainfall almost at more doorstep.

Convection taking place here too, but nothing too promising!

The East Anglia event was not something I had predicted either, where we all learn!

Netwx SR in line with current radar with precipitation over SW, could spark over this possible thunderstorm over CS England/SE Midlands!

Certainly interesting day ahead for some... Tony of UKWW making very unexpected forecast for today as below, a small chunk I have taken. The WRF MO1 to 4 simulations try to develop an area of strong convection further south (Midlands) later today. This zone should hold the best deep layer speed shear for this convective period. As a result I might have to persuade my parents to take me along the M4 Corridor!

Not according to the radar no showers/storms to your South at all, all storms are NW Liverpool and Carlisle area.

So glad Holyhead was virtually underneath the mass of storms, I was worried you wouldn't see anything but glad you enjoyed yourself! We are already at 20,000 lightning strikes for today and it's not even 8am yet!

It's funny because I'll stay up for storms that won't even come near me, I just love watching the radar for hours on end!

I've never travelled to a location to watch a storm so I'm no expert but you could probably see lightning from Holyhead right now.

Yeah it'll probably take 30-45 minutes for the storm to reach Holyhead and by then if it all weakens I'd be amazed! Even then it'll probably begin to back build too, I can see this storm lasting several hours now given the conditions that it's in.

Over the Irish Sea definitely building in size, lightning activity and most active furthest east, definitely a multi-cell I'd say.

Various sferics appearing near to storms but not close, must be anvil crawlers poss?

Why are we seeing fake strikes on the lightning map, getting annoying:(

Agreed but haven't seen anything, I've got my eyes peeled!