Jump to content
Will it snow? 7 day forecast Weather Radar Will it be cold?
Snow?
Local
Radar
Cold?

Lewis

Members
 View Profile  See their activity

  • Posts

    2,442

  • Joined

  • Last visited

  • Days Won

    3

 Content Type 

Posts posted by Lewis

    Uk Convective General Discussion & Forecasts, 26th June 2012>

    in Storms & Severe Weather

    Posted

    Hmm, its still all over the place with the models for Weds night into Thursday and i am too tired to make heads or tails of it now so i think bedtime for a few hours and then wake up refreshed in the morning with the hope of some better agreement between the models.

    I do, however, feel reasonably confident that the East Midlands and Lincolnshire into East Anglia will be the best placed areas for tomorrow. Question is, after i have spent the afternoon pottering around these lands should i then be driving down to the southwestern coasts for a possible overnight MCS, go home and wait for more storms on Thursday or just sleep on a park bench somewhere awaiting a morning drenching biggrin.png

    I feel so privileged :)

    BLn_6T.png

    GZgogJ.png

    T5u3gl.png

    ffCR26.png

    4A_qd0.png

    Uk Convective General Discussion & Forecasts, 26th June 2012>

    in Storms & Severe Weather

    Posted

    Massive upgrade for NW areas on the 12z output for Thursday - Lewis

    We see a delay on the approaching CF from the West, with a high amount of CAPE and a negative Lifted Index and lifting this will spark storms off quite readily across NW parts of England and West Yorkshire.

    As we head on through the day during thursday the risk extends further east and north eastwards, as the CF pushes through the energy will transfer eastwards.

    Yorkshire, Lincolnshire and parts of the East Midlands looks the areas at greatest risk.

    Further SE across England it looks to be drier, with some home grown cells expected to fire up, as for Southern most counties some imports are likely along with Kent and the far SE later on in the day.

    ukcapeli.png

    As the cold front moves through, areas behind will destabilize fairly quickly. Dew points are expected to be around the 17-18c mark.

    Any areas that see prolonged sunshine will see home grown cells firing up, where CIN levels are favorable.

    There is also a large upgrade on storm potential for much of England tomorrow (Wednesday), more so for Eastern areas, with CAPE values around 1000 j/kg and a Lifted Index of around -4.

    ukcapeli.png

    Storms may become slow moving, giving torrential downpours, frequent lightning, and hail. Flash flooding is a possibility.

    A video forecast will be made shortly, and I will continue to update forecasts when models update, we are coming in to range now with the higher resolution models (NMM and NAE) which will give a better indication as to which areas are more likely to see any thunderstorm development.

    Uk Convective General Discussion & Forecasts, 26th June 2012>

    in Storms & Severe Weather

    Posted

    I'm very happy with the 06z GFS, coming in to NMM range now. Some 900-1100 cape around the South and West/East Midlands tomorrow with a -4 LI. Could be some very slow moving torrential storms tomorrow for these areas.

    Looking forward to it coming in range for Thursday.

    Also guys, as you aware we run the UK storm chasing network, we are arranging some chases/events for tomorrow and also Thursday, if you want information or want to chase with us you can follow us on facebook for the latest information.

    We have a few experienced net-w members leading the way!

    https://www.Null

    Lewis

    Uk Convective General Discussion & Forecasts, 20th June 2012>

    in Storms & Severe Weather

    Posted · Edited by Humber

    This is my biggest worry, and is one of the major factor/player which will decide whether Eastern and NE areas will get thunderstorms, or just a damp squib.

    The cold front is expected to move through around 11am-12pm across NW England, N england running in to Yorkshire.

    The warm moist air, and high CAPE values start building around mid-day around the East Midlands/SE England. Energy and CAPE values rapidly head North.

    There's very little in the way of CIN, and dew points are generally lower than the other models on the GFS, against the NAE for example.

    So this suggests to me, that the cold front may move though quickly, leaving us with overcast conditions, and a damp squib basically, if it moves through too quickly we lose our trigger.

    GFS = Knife edge.

    So it all goes down to this CF on Thursday for Northern areas.

    If it goe's smoothly it'll be a cracker, but it can easily go wrong!

    The ideal situation is for it to stall and slowly move ENE'wards, but this would be asking too much.

    Lewis

    Uk Convective General Discussion & Forecasts, 20th June 2012>

    in Storms & Severe Weather

    Posted · Edited by Humber

    Optimistic I must say!!! Im surprised you opted to say confidence is high over this event...IMO confidence is low at this stage but with a potentially High impact.

    Also, what is CIN looking like? I've haven't got the NW package which enables me to check the numbers (tight fisted I know)

    It is almost exactly a year to the dot the charts were showing similarly obscene numbers, yet only the SE quadrant largely saw any benefit as the timing of the front engaging the plume shifted by up to 24 hours which saw vast swathes miss out (and even that was at very lastminute.com change in forecast.

    In any event I'm praying whatever action there is is NOT Thursday day time as I am in meetings all day cray.gif

    Hi harry,

    At the moment I would say confidence is rather high, although the impact is low to moderate as we cannot be sure of certain factors, I agree that forecasting thunderstorms for any giving location nevermind county 4 days out is virtually impossible, but what I do believe is that the confidence of an event certainly is high, and it cannot be ignored due to the frequency in which the GFS continues to plot the very unstable conditions in the form of a plume.

    These type of setups can be extremely tricky to plot, as you mentioned above one of the major factors to enhance the development is the timing of the front.

    I issued an early weather watch because of the consistency to show the right conditions to generate thunderstorms.

    The CIN (Convective Inhibition) is patchy during Wednesday with coastal areas around the SE, East, SE, and NW having the values;

    wyz40P.png

    As we head on it to Thursday it's patchy to start with with Eastern areas holding on to the values during the course of the late afternoon and early evening overnight.

    ch4xO7.png

    i_ir5M.png

    HD7UrU.png

    Will be interesting to see what the 18z brings, but I must add it's looking increasingly stormy middle part of next week smile.png

    Dew points are a little lower and the higher values are less widespread on the 12z, with the higher dewpoints around the SE of England, with Yorkshire and Lincolnshire hitting dew points between 17-18c during the evening.

    s2kNL4.png

    Lewis

×
×
  • Create New...