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Gordon Webb

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About Gordon Webb

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    27 days to autumn equinox 119 days to christmas

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    Darts , Football , Playing PC Games And Surfing The Net
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  1. Metcheck still have their focus on the Pennines and Northern England later this afternoon
  2. looks like all the activity will be mainly to my east as I'm barely in the slight risk zone which suits me fine as I have 2 overgrowing lawns that need my attention and I suspect Lightning , torrential rain and lawnmowers won't mix well together
  3. well according to Metcheck they have the risk starting in Northern England tomorrow afternoon then extending south to the midlands and NE England later but they will update tomorrow after overnight model runs so nothing set in stone whatsoever
  4. Hasn't brightened up at all here today , I mean if I said it had tried to brighten up I would be overstating it ,
  5. One thing I'll say looking at the radar these are not hanging about , I suspect they've realised that there in the south and are hotfooting it to the north as quickly as possible
  6. Day 2 Convective Outlook VALID 06:00 UTC Fri 09 Aug 2019 - 05:59 UTC Sat 10 Aug 2019 ISSUED 21:58 UTC Thu 08 Aug 2019 ISSUED BY: Dan An upper low will swing northeastwards across Ireland on Friday, reaching Scotland by Saturday morning. An occluding frontal system will stretch from Northern Ireland to southern Scotland and northern and eastern England first thing on Friday morning, gradually lifting northwards through the day. Pockets of embedded elevated convection will be possible, although pinpointing exactly where some sporadic lightning may occur is near-impossible and overall is not expected to be too widespread. A wrap-around occlusion will provide for the focus for a band of heavy, showery rain over the Celtic Sea and southern Ireland on Friday morning, encircling the main surface low. This whole system, including band(s) of showers / showery rain, will gradually migrate northeastwards across the whole of Ireland and Irish Sea into Wales, western and northern England and southern Scotland. Some sporadic lightning will be possible in places, but dependent somewhat on sufficient cloud breaks to allow adequate surface heating in-between the showers. Either way, strong steering winds will ensure relatively fast movement of individual showers across England and Wales, although this high momentum may be mixed down to the surface at times in downdrafts to produce some gusty winds. Since a single shower is unlikely to last for long, this will ultimately limit how much rain accumulates - but elements of shower training could occur which may exacerbate existing saturated ground. An isolated tornado will be possible given strong low-level shear. Over Ireland, the proximity to the upper low will result in more "pulse type" convection given weaker shear and slower storm motion, which brings the risk of localised flooding from prolonged downpours. In-between the early morning frontal rain clearing and the first (of many) wrap-around portions of the occlusion arriving, a window of clearer sky will exist for better diurnal heating across northern England and southern Scotland. Given surface dewpoints of 15-19C (at least for a time early afternoon), up to 1,000 J/kg CAPE will be possible. A strip of dry mid-level air will overlay this warm, moist low-level airmass, creating a rather unstable environment with reasonably steep mid-level lapse rates. If sufficient heating can occur, scattered showers and a few thunderstorms could develop. The main risk period with a favourable overlap of various ingredients will be 10z-15z, but there could be a second wave of showers/thunderstorms late afternoon lingering well into the evening hours. Given the potential for a couple of waves of shower/thunderstorm activity, a low-end MDT has been issued. Given the sheared environment, a supercell may be possible, capable of producing hail up to 2.0cm in diameter and perhaps an isolated tornado. Looks like Northern England and Southern Scotland the Places to be again http://convectiveweather.co.uk/forecast.php?date=2019-08-09
  7. And also for Leicester and rutland obviously in response to developments that occurred within last hour to ninety minutes
  8. Update from PJB 10:00 Update Changes to Risk Boxes - None Detail The 05Z Nottingham ascent demonstrates the changes taking place in the lower and upper atmosphere quite nicely as GPH is eroded as a more cyclonic upper air pattern begins to move in from the west. The Ascent shows slowly warming at the 850mb level and slight cooling aloft. It also shows the slowly increasing and more favourable upper level kinematic environment. At 850mbs a zone of higher Theta-W is moving north across Central Southern England and this will find its way across Northern England during the afternoon. This higher Theta-W Plume will manifest itself as 850mb Theta-W >16C as we go through the afternoon and translate to fuel surface based storms which are likely to fire across Northern England. At the surface a prefrontal trough is moving across Wales, SSW winds behind the trough and SSE or SE winds ahead of the trough moving NNW across the Midlands and into Northern England . Temperatures are already approaching 20-21C across these areas and HRV imagery indicates only cold Ice cloud spreading north across the Midlands, though some thicker Alto-status or Alto-cumulus across CS England. Airmass imagery depicts a zone of increased vorticity moving NNE and this is indicated in the various model output which shows an area of increased 700mb, 500mb and 300mb Vorticity moving NE associated with a shortwave moving NE ahead of the main cyclonic vorticity centre. At 500mbs and 300mbs there is an increase in Jet Energy over Southern England, so some additional shear vorticity is likely to spread across Northern England from this Jet and at the same time we will see a strengthening SSE Jet moving NE across Ireland and Northern England finds itself under a positive area of enhanced divergence aloft as the two Jet's come together. Storms are likely to erupt across NE Wales, NW Midlands, and the Greater Manchester area and towards Derbyshire during the afternoon and move NE wards. SSW Trajectories, though if they climb high enough more likely to be steered eastwards across the Pennines and towards the Sheffield area. Modifying the Ascent at Nottingham to a temp of 24C and DP 15/16C yields significant CAPE available at over 1300 j/kg MUCAPE . Storms routed to the surface where the highest Theta- W will be located ,however the storms also will tap into the increased energy at 850mb as the zone of higher Theta-W moves and advects NE across N England. The most energy available therefore across the PURPLE BOX area on the risk map. Storms have the possibility to give very heavy or torrential rain. Given the areas likely to be affected there is scope for significant further flooding to already damaged areas and areas under recent flood warning and flood watches. Fig 1- Storm Risk Map Fig 2- Hirlam Streamlines showing the confluence and convergence across N England during the afternoon . Fig 3 - Arpege 850mb Theta- W Showing the zone of highest Theta-W during the afternoon , Storms likely to tap into this additional favourable environment and use it as additional fuel for storms. Fig 4 - Jet Energy increasing through the afternoon. Deep Layer Shear increasing and the overall kinematic environment increasingly favourable . Fig 5 - Nottingham modified ascent. Edit - Images Are very small and don't enlarge when clicked upon go here http://www.ukweatherworld.co.uk/forum/index.php?/topic/122052-convective-outlook-sunday-4th-august-2019/ to see them in enlarged size when clicked upon
  9. Sure does look like it unfortunately places Like Derby And Yorkshire who really don't need it also look in the firing line let's hope those areas miss the worst of it
  10. yeah maybe but their warning is of thunderstorms and outbreaks of heavy rain so they haven't put all their eggs in one basket so they covered themselves , convective weather also suggested saturated profiles which will tend to limit lightning potential with an exception of N/NW England and scotland , specific line below hence conditions will be favourable for a greater coverage of lightning activity over N / NW England, adjacent Irish Sea and perhaps SW Scotland, especially enhanced by both orographic forcing and low-level convergence during the afternoon and evening hours
  11. Convective Weather Forecast Day 2 Convective Outlook VALID 06:00 UTC Tue 30 Jul 2019 - 05:59 UTC Wed 31 Jul 2019 ISSUED 20:38 UTC Mon 29 Jul 2019 ISSUED BY: null A near-vertically-stacked low (slightly tilted to the NW with height) will drift slowly northeastwards from Devon to Yorkshire through Tuesday and Tuesday night. The associated upper cold pool will overspread warm SSTs and diurnally-heated land to bring a day of widespread deep convection. Showers and perhaps a few weakly-electrified thunderstorms will already be affecting parts of SW England / S Wales early on Tuesday morning, and are expected to expand in coverage across much of Britain through the day - organising into distinct circular bands rotating around the main surface low centre. Instability will increase through the day in response to diurnal heating, with 300-700 J/kg CAPE likely fairly widely, and up to 1,000 J/kg CAPE in parts of northern England and SW Scotland. Almost any shower could produce a few sporadic lightning strikes, although fairly saturated profiles / excessive cloud cover and fairly weak shear will tend to limit the lightning potential. That said, a zone of steep mid-level lapse rates will exist on the northern flank of the upper low, in an environment with some reasonable shear and good forcing aloft, after a morning of relatively cloud-free skies - hence conditions will be favourable for a greater coverage of lightning activity over N / NW England, adjacent Irish Sea and perhaps SW Scotland, especially enhanced by both orographic forcing and low-level convergence during the afternoon and evening hours. As such, a MDT has been issued for the risk of lightning - and here hail up to 2.0cm in diameter will be possible from the strongest cells. An isolated supercell cannot be ruled out if organised convection can develop relatively early before shear reduces through the afternoon. The main threats will be flash flooding from both slow storm-motion (so prolonged downpours), but also shower training over similar areas - especially given already saturated ground from recent heavy rain over the NW Midlands / NW England etc. There could also be quite a few funnel clouds / weak tornadoes (or waterspout) close to the low centre (so primarily in a zone from the West Country to the W Midlands, and later NW England). http://www.convectiveweather.co.uk/forecast.php?date=2019-07-30
  12. the get out clause of that forecast and tomorrow's forecast is outbreaks of heavy rain , if people are reading into that forecast that everywhere will get thunderstorms I think a few will be disappointed with just heavy rain and the closest they'll get to a lightning strike will be watching replays from last week
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