Convective Outlook: Sun 05 Jun 2016
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sun 05 Jun 2016 - 05:59 UTC Mon 06 Jun 2016

ISSUED 15:04 UTC Sat 04 Jun 2016

ISSUED BY: Dan

Broad Omega Block pattern persists, with ridging aloft atop a warm, moist high WBPT airmass. Like Saturday, there may be some hints of residual medium-level instability close to SE England first thing on Sunday morning, but the overall theme will be diurnal heating and low-level convergence / orographic forcing creating sufficient forcing for localised deep convection - and hence isolated to well-scattered showers and thunderstorms are possible late afternoon through the evening hours. 


SLGTs have been issued where confidence is a little higher for at least some isolated thunderstorm development, but there will be scope outside of these areas for other isolated cells - with potential for the SLGT to perhaps be extended across Wiltshire / Dorset / Hampshire / Somerset etc if confidence improves.

DLS is fairly weak and so convection will be rather messy and disorganised, but slow storm motion (given slack flow) in an environment characterised by PWAT 25-30mm suggests 15-18mm rainfall accumulations may occur in just 1 hour, giving a risk of local surface water issues. Hail up to 1.0cm in diameter will be possible in the strongest cells.

Also, some uncertainty, but there is the potential for elevated convection to be imported to parts of SE England later on Sunday night, hence the extension of the LOW threat level here.