Convective Outlook: Wed 30 Mar 2016

LOW SLGT MDT HIGH SVR

What do these risk levels mean?

Convective Outlook

VALID 06:00 UTC Wed 30 Mar 2016 - 05:59 UTC Thu 31 Mar 2016

ISSUED 16:55 UTC Tue 29 Mar 2016

ISSUED BY: Dan

Broad upper trough across British Isles will lift northwards as the main jet stream core bulges northwards across southern Britain. At the same time, upper trough axis west of Ireland will continue to approach from the Atlantic, while sharpening.

Therefore, yet another day of widespread but low (non-zero) chance of lightning, particularly so from the Bristol Channel - The Wash northwards, with cold mid-levels combining with diurnal heating to generate 200-300Jkg^-1 CAPE. Expect scattered showers, particularly in northern and western areas, with a low spot-location chance of lightning - in general, areas most likely to see this are C / E Ireland.

Have extended the LOW towards S/SE England and Home Counties, despite the lack of any significant instability, to cater for the (low) risk of lightning given the highly sheared environment as the jet stream continues to migrate slowly northwards, perhaps inhibiting the depth of convection somewhat. There will likely be a lot of medium/high cloud spilling northwards, but nonetheless a few scattered showers may develop and drift slowly eastwards, aided by low-level wind convergence. Shower training may occur here.

Once more, small hail is likely in any stronger cells that develop.