[Tony Gilbert]

Posted 11.26am Sat

Confidence level ; Low

Slight Risk of Thundery Showers Central and NE regions UK and Central East Eire 14Z-19Z

Surface Low moves NE across UK with a number of wrapped occlusion triggering rain to some parts and convective showers where surface heating is increased. Upper short wave trough moves away to the east through today though will continue to influence lapse rates for a time. WRF and GFS both showing signs of good instability with CAPE values topping 600 J/KG for NE UK. Fairly weak deep layer shear and limited potential instability will lessen any severe potential . Though an experimental marker box is placed over SE tip of Scotland and Northumberland where strong convergence will exist with a surface vector running under an opposing 850mb flow. Vorticity looks to be ripe here for a short period through the afternoon. Remainder of the yellow box should see some strong low level shear in place where storm will be more than capable of developing short lived mesocyclones for a time.

Cannot rule out the odd sharp shower over E.Anglia this afternoon. The region whilst quite dry shows strong potential instability so any showers that do occur will anvil quite rapidly.

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[Tony Sales]

Mmmm I like it when the Red box is over me thanks for the outlook Tony

[Tony Gilbert]

Today's results

Some very isolated sferic acivity noted NW Midlands and NE UK. Though in general the convection looked pretty benign. Below is Cambs and Alb soundings 12Z; Conditions which stand out the most is the skinney CAPE by comparison to earlier model predictions from both GFS and WRF and complete saturation up to the tropapause. The lapse rates were never likely to be that steep but this combined with lack of potential instability weakens any upward motion of any lifted parcel even further. Regions close to the occlusions look to have heavy cloud cover for much of the day and most parts barely saw anywhere near the expected surface temps.

Though always good to see why things sometimes turn out the way they do!

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This post has been edited by Tony Gilbert: 16 June 2012 - 19:22