Jump to content
Sign in to follow this  
Nick F

Storm & Convective Discussion - 7th August Onwards

Recommended Posts

Some actual proper wet snowflakes mixed in with the rain during a brief heavyish shower, here. 

An earlier shower produced more in the way of a rain and graupel mix. 

Temperature got down to 1.9*C at one point!

A very impressive shower you guys had in London, though. Am kinda jealous, lol! But well done to you lot!

Share this post


Link to post
Share on other sites

Not a great photo, but I took a picture of that storm north of my location that produced a few lightning strikes according to the radar 

 

IMG_1385[1].JPG

Share this post


Link to post
Share on other sites

Just waiting for this thing of beauty to come and give me some white stuff.😀

Over Northampton now.

 

20190403_180615.jpg

Share this post


Link to post
Share on other sites
1 hour ago, convector said:

Some decent storms around today, not much in the way of lightning activity but plenty of hail and things to look at. These setups have surprised me before so i figured i'd try chasing them this time. 

I set out around 3:30 and headed north on the A34. The cells near bicester looked promising and the lack of shear made it really easy to get up close to them - they were pretty much just building on the spot.

56537453_442192326522492_7308896261652873216_n.thumb.png.43bead6488a244b482a994cf0f52dc6c.png

This thing put out a tonne of hail and and couple lightning strikes before dying out. At 4:45 the focus shifted north and i decided to drive west on the A41 to get ahead of the rain. By this time new cells were developing over milton keynes and going strong. i blasted north into buckingham and got this picture before my phone gave up on me. 

56589739_2295751007373160_5961306609895342080_n1.thumb.jpg.57ab3ec7f87caed7fefa57f6f2153e8d.jpg

The one on the right was decaying but the updraft on the left kept going and left a huge hail swath on the route i was taking. It also put out a lightning strike, which i heard through the car. Not bad for this time of year.

I continued chasing, going north west through MK and then up into northampton by about 6pm; by this time the sun was setting and i was running out of fuel so i called it a day. Went pretty well, i'll definitely need to buy a dashcam for next time.

Something about the A41 builds storms beautifully. MK is often.a sweet spot 

Share this post


Link to post
Share on other sites

pics from the thundery shower / storm that just hit here IMG_1156.thumb.JPG.519f97c599c6123902a240242addf9ae.JPGIMG_1157.thumb.JPG.65a94d7cd198d00454a7952588fa91cf.JPGIMG_1158.thumb.JPG.5ff185018e720f4c19016a5769ab1403.JPGIMG_1159.thumb.JPG.a61b3d70568c5825ac8283171964caef.JPGIMG_1160.thumb.JPG.284003e2a88296261f52908223cd22d9.JPGIMG_1161.thumb.JPG.ffba76cbacf530203d754a6ed109fafa.JPG

Share this post


Link to post
Share on other sites

Just heard thunder. Looks dark to the west so probably came from there. 

3C27E62A-1B34-43FE-9E90-5E1DCDD96B3D.jpeg

Share this post


Link to post
Share on other sites

Day 2 Convective Outlook

VALID 06:00 UTC Sat 06 Apr 2019 - 05:59 UTC Sun 07 Apr 2019

ISSUED 19:25 UTC Fri 05 Apr 2019

ISSUED BY: Dan

... ISLES OF SCILLY / CELTIC SEA ...

On the northern edge of the elongated upper low to the southwest of the British Isles, a shortwave will move northwestwards across the Celtic Sea and southern Ireland on Saturday. Elevated showers and one or two thunderstorms will be possible over the Scilly Isles initially, and over open waters to the south of Ireland during Saturday morning. 

... IRELAND ...

The associated cool mid/upper-levels with the aforementioned shortwave atop surface heating over southern and western Ireland will help generate a few hundred J/kg CAPE. However, main limiting factor is the fact that the shortwave is likely to move through before peak heating, so questionable as to how much of a favourable overlap will exist. Nonetheless, a few isolated showers seem possible for a time within a reasonably sheared environment, and hence at least a low risk of lightning.

... E ENGLAND ...

Towards the end of Saturday night (i.e. nearer 06z Sunday) remnant / weakening instability will drift across the North Sea towards eastern England, with the potential for a few elevated showers atop a very moist boundary layer (sea fog / low cloud quite likely). There is a very low risk of a few isolated lightning strikes with these showers, however given weak instability and very late arrival (it could be beyond 06z before any make landfall) for now we refrain from issuing any threat levels here.

http://www.convectiveweather.co.uk/forecast.php?date=2019-04-06

Share this post


Link to post
Share on other sites

VALID 06:00 UTC Mon 08 Apr 2019 - 05:59 UTC Tue 09 Apr 2019

ISSUED 19:53 UTC Sun 07 Apr 2019

ISSUED BY: Dan

A quasi-stationary warm front will straddle Ireland - Wales - SE England for much of this forecast period, resulting in a broad corridor of modest ThetaW air. Extensive low cloud and fog is expected initially on Monday morning due to the very moist low-level airmass, while showery bursts of rain will occur in a rather random fashion within this ThetaW zone due to subtle forcing aloft coupled with some mid-level instability. While a few isolated lightning strikes cannot be ruled out, very little is expected given the weak forcing, marginal instability and fairly saturated profiles.

There is good multi-model agreement for cloud cover to become more broken during the day, allowing increasing amounts of insolation and hence surface heating. Temperatures of 16-18C seem plausible on Monday afternoon to the north of the frontal boundary (i.e. East Anglia, the north Midlands and southern parts of northern England) with dewpoints of 10-13C. Profiles will become increasingly unstable, with 500-800 J/kg CAPE possible over these areas.

In a rather slack pattern with weak forcing aloft, low-level convergence and associated moisture pooling will serve as the primary forcing for ascent, with a few isolated to well-scattered thunderstorms possible from mid/late afternoon onwards into the evening hours - particularly within the SLGT area. Generally weak shear (winds both similar in direction and speed through the profile) will result in pulse-type convection, where an individual thunderstorm may only last an hour or so. An easterly steering flow will result in storms drifting to the W or NW with time, their slow motion bringing the risk of some localised surface water issues. It is worth noting that due to some uncertainty over the exact position of the warm front, this SLGT may need shifting north or south slightly.

Depending on sunshine amounts, sea breeze convergence may also aid the development of one or two isolated heavy showers/thunderstorms over East and West Sussex during the late afternoon/early evening, especially combined with additional forcing over the High Weald. An additional, small SLGT may be introduced here if confidence improves on this potential.

During Monday evening and night, increased forcing aloft approaching from France will result in more widespread outbreaks of showery rain developing across southern England / south Midlands / south Wales and across into Ireland. This will tend to become a messy mix of convective and increasingly dynamic precipitation, and while some embedded lightning is possible - especially at first - marginal instability and saturated profiles precludes the need for any SLGTs to be issued for this part of the forecast.

http://www.convectiveweather.co.uk/forecast.php?date=2019-04-08

Share this post


Link to post
Share on other sites

 Looks like the first insolation driven convective day of the year here today. A nice flow direction but WRF 18Z not going for much CAPE at all in my location despite a projected max temp of 18.9°C. 

Share this post


Link to post
Share on other sites

Netweather short-range model has a nice cluster of cells forming into a more intense line from Wales to Norfolk this afternoon before fading out past dark, blue-skies here too with 16'c expected. MWIS and EGCC METAR expecting isolated heavy-Thundery showers with the possibility of hail.

Share this post


Link to post
Share on other sites

Well our area needs at least 10 consecutive warnings to see even a glimmer of lightning (and we’ve only had about 2 so far this year) - but I hold out hope for later on today. Chance of some messy convective imported stuff later in the evening too - but I reckon the best shot I’ve got is seeing some distant flashes from the hill in Gford as it gets dark... 🤞

Share this post


Link to post
Share on other sites
1 hour ago, Flash bang flash bang etc said:

Convection kicking off over Cambridge?

Looks like a little bit. I expect something more will happen in a couple hours if convergence sets up right - maybe around northamptonshire

Share this post


Link to post
Share on other sites

A lot of cloud hampering prospects by the look of it on the satellite imagery. However, by late afternoon, things could look a lot more promising.

Gorgeous blue skies here with a few puffs of Cu. 

Share this post


Link to post
Share on other sites
17 minutes ago, convector said:

Looks like a little bit. I expect something more will happen in a couple hours if convergence sets up right - maybe around northamptonshire

Bah! I’m hoping for more of a High Wycombe / Slough area, but we’ll just have to wait and see 🙂

Share this post


Link to post
Share on other sites
Posted (edited)
22 minutes ago, Mapantz said:

A lot of cloud hampering prospects by the look of it on the satellite imagery. However, by late afternoon, things could look a lot more promising.

Gorgeous blue skies here with a few puffs of Cu. 

Getting humid underneath the cloud cover here in Birmingham....14 and rising ....Im liking the EWN forecast from your site....which gives us something to look forward to later on

cracking picture on the webcam by the way

Edited by Arnie Pie

Share this post


Link to post
Share on other sites

Seems to be some stuff bubbling up along the Suffolk coast now, will be interesting to see what develops over the next couple of hours.

Share this post


Link to post
Share on other sites

Clear skies here but a little hazy which is suppressing temperatures a little bit compared to forecast. Currently 15.5°C. 

Share this post


Link to post
Share on other sites

Posted in completely the wrong place earlier - but some sferics showed up over to the west of Cambridge.

Still waiting for some decent sunny spells here but there seems to be a lot of cloud still 😬

Share this post


Link to post
Share on other sites

Just heard 1st  and 2nd clap of thunder of the year near daventry , northants.

Share this post


Link to post
Share on other sites

Incoming cells from our East are looking interesting for the South of Birmingham

Share this post


Link to post
Share on other sites

Loud thunder and lightning with heavy rain in Rugby 

On 09/08/2018 at 20:14, Summer Sun said:

Day 2 Convective Outlook

VALID 06:00 UTC Fri 10 Aug 2018 - 05:59 UTC Sat 11 Aug 2018

ISSUED 19:03 UTC Thu 09 Aug 2018

ISSUED BY: null

A sharp upper trough will move from west to east across the British Isles on Friday bringing the potential for widespread convection/showers. Ridging/rising heights will follow the trough brining drier, more settled conditions into Ireland and eventually western/southwestern Britain later in the day. Widespread showers and a several thunderstorms are expected, especially across parts of England. 

 
Generally moist profiles and surface to 500mb delta-Ts reaching into the mid-40s will help to generate in excess of 500 J/kg of CAPE by the afternoon across much of central and eastern parts of England. Even further north into Scotland, as well as parts of Wales and northern and eastern parts of Ireland will see convection quite early on before ridging begins to limit the risk later. Shear profiles are relatively weak in central and northern Britain, but there is a pocket of higher shear across southern England that could help invigorate shower potential in southern England during the afternoon (perhaps with a few embedded line-segments). 
 
As a result, heavy showers and a few thunderstorms are possible across a large part of the British Isles, but the favoured zones for lightning potential seem to be across northern England, south to a line from Liverpool Bay to the Wash (higher CAPE), and across southern England south of the M4 (higher shear). 
 
Showers will peak with afternoon heating, and generally fade away with a combination of the upper trough clearing eastwards and the lack of surface insolation. 
 
Heavy downpours with localised flash flooding will be the largest risk, along with some hail to 1-1.5cm under the deepest convective cores in the northern SLGT area. 

http://www.convectiveweather.co.uk/forecast.php?date=2018-08-10

 

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×
×
  • Create New...