Storms and Convective discussion - July 2023

[Eagle Eye]

Convective Outlook 

Tuesday

Areas of 500+ J/KG of SBCAPE allow for a few low end slight risks with pulse storms forming in areas of weak DLS. Upscaling appears unlikely and generally thundery showers appears to be the main mode though a few clusters could form along stronger forced areas.

A few storms could reach above 20,000 feet increasing their lightning potential with their increased ECAPE. Buoyancy is rather weak though so air parcels will have to stay parallel to the flow for a while to reach that potential height. So generally sparodic lightning is most likely.

Strong LLLR's may aid some small hail but given weak buoyancy and small updraft widths, hail would be very small if it does form. Along with the weak MLCAPE.

Late morning and early afternoon is when the SW slight risk comes into play with a few sparodic showers and storms along the coastal areas along a falling moisture tongue.

Then the risk shifts further east for the afternoon (mid-day onwards to early evening). The SE has SE'ly moving storms sparodically throughout the afternoon and evening whereas the NE has slightly more clustering of storms at their strongest between around 4 and 7 with stronger MLCIN in the area.

[Thunders]

Finally I’m in the area and I’m included in the storms again, about time for the SE to up its game, was in chertsey yesterday, when I was driving back, black clouds and tons of rain no, I rumble of thunder other than that haven’t seen anything else

 

[Flash bang flash bang etc]

On 21/07/2023 at 16:44, Tamsin said:

Granted there's not been much activity in South London but I've been really pleased with the cloudscapes this summer 

Nope… I shan’t allow it . I am on weather strike until we get thunder

[Thunders]

large amount of heavy rain here rn, think itwill drain all the cape away sadly

[Thunders]

[alexisj9]

10 minutes ago, Thunders said:

large amount of heavy rain here rn, think itwill drain all the cape away sadly

Not sure, guess we'll see.

[alexisj9]

35 minutes ago, Thunders said:

I think it's just a trough showing where conditions change, behind it I think showers may build a bit better. Just looking at radar, we'll see what the showers behind do. I don't think our risk starts till later on anyway.  I've now looked at the forecast nick put out, its coastal convergence.

Edited July 25, 2023 by alexisj9

[Rufus Butterfield]

Been a tiny storm over Scarborough 

[LIGHTNING ACTION]

South of York

Shame it's moving south

[Sparkiee storm]

Some nice convection here atm, looks like a few new showers are developing.

[Thunders]

nothing much here again today

[Flash bang flash bang etc]

Interesting that there seems to be a regular blob of heavy showers on the far SE tip over the last few days - accompanied with some fairly interesting weather phenomenon.

Wonder if this is just a small sign of a shift beginning to occur which may mean more significant weather events may be on their way (some decent clippers in august?)

This isn’t based on anything other than casual obsvs. Would be interesting to know more from anyone with a better grasp of what the models are suggesting

[A.J]

nice cheeky little thunderstorm here at the moment...12 good rumbles so far, some good flashes of lightning plus one good bolt just off shore...a very pleasant surprise 

[A Face like Thunder]

6 hours ago, swny said:

South of York

Shame it's moving south

Forecast was correct, with heavy showers, including a bit of hail, around Pickering, the Vale of York and on the A64 going towards Leeds between 1 pm and 2pm. No thunder of lightning noted but not the first time recently that the area has been subjected to these heavy showers.

[Eagle Eye]

Convective Outlook 

Wednesday

A warm front will track E alongside pockets of instability, bringing the risk of the odd isolated lightning strike. Most lightning activity will stay offshore of W Ireland & W Scotland, although the odd strike/rumble could be seen behind the front.

 

[Alderc 2.0]

Only one type of drought this year and it’s a convective drought. Had a very short unexpected storm in the first week of January and nothing since. Think I might of missed another short storm while away on holiday but it’s been slim pickings for the south coast this year with not a single plume event. That looks like continuing into well into August as well. While there are exceptions like last October I always feel like plume potential diminishes after July.

 

[alexisj9]

13 hours ago, Flash bang flash bang etc said:

Interesting that there seems to be a regular blob of heavy showers on the far SE tip over the last few days - accompanied with some fairly interesting weather phenomenon.

Wonder if this is just a small sign of a shift beginning to occur which may mean more significant weather events may be on their way (some decent clippers in august?)

This isn’t based on anything other than casual obsvs. Would be interesting to know more from anyone with a better grasp of what the models are suggesting

Nah, it's just the wind direction, NW, causing convergence on the coasts.

[Flash bang flash bang etc]

2 hours ago, alexisj9 said:

Nah, it's just the wind direction, NW, causing convergence on the coasts.

That makes sense

[Metwatch]

Was scrolling through the mildy interesting reddit page and saw this amazing rainbow capture from above.

The airline seems to be Cayman airlines so I imagine taken somewhere in the Carribean, not far from the Cayman islands. Super cool! 

[Eagle Eye]

A bit of stuff off my camera from recently.

 

 

 

 

 

[Flash bang flash bang etc]

 

He’s right you know

[Eagle Eye]

Convective Outlook ️

 

Cloud cover will limit any showers/storm development over Thursday although if cloud cover does break the odd storm could be expected. 

 

A lot of uncertainty on when this cloud does break therefore only a LOW has been issued.

[Thunders]

2 hours ago, Eagle Eye said:

Convective Outlook ️

 

Cloud cover will limit any showers/storm development over Thursday although if cloud cover does break the odd storm could be expected. 

 

A lot of uncertainty on when this cloud does break therefore only a LOW has been issued.

Wont be down south 

[SilverWolf]

Hi, can someone briefly explain the ‘numbers’ on the V4 radar for Convective Inhibition (currently -40 where I am) and Lifted Index (currently 1). And what the best combination is for storms forming? Thanks… CAPE is creeping up, and we’ve had full sun for an hour or so. 

[Eagle Eye]

26 minutes ago, SilverWolf said:

Hi, can someone briefly explain the ‘numbers’ on the V4 radar for Convective Inhibition (currently -40 where I am) and Lifted Index (currently 1). And what the best combination is for storms forming? Thanks… CAPE is creeping up, and we’ve had full sun for an hour or so. 

Convective inhibition is sort of the anti-CAPE. Think of it as taking away from how much CAPE can be used. Its not a direct 1 to 1 though. Above 200 is considered high CIN. Above about 100 I'd say is moderate and Above 20 is when it tends to affect convection slightly. Before that it doesn't really seem to affect much.

Lifted index is how buoyant an air parcels is. E.g. How much an air parcel can go up or is resistant to going on. In fact its useful I find in determining updraft widths and hail size forecasting. You can try and forecast storm strength using it if you want to but its not a guarantee of anything I find.

A good surface lift is below 0

One for decent storms is around below -5 I find. Beyond -8 and storms tend to become more severe.

If taken from the 850's level then anything below 0 is stormy.

Its the difference between the parcel and the environmental temperature.

Edited July 27, 2023 by Eagle Eye