Convective Outlook: Thu 26 Sep 2019

LOW SLGT MDT HIGH SVR

What do these risk levels mean?

Convective Outlook

VALID 06:00 UTC Thu 26 Sep 2019 - 05:59 UTC Fri 27 Sep 2019

ISSUED 06:48 UTC Thu 26 Sep 2019

ISSUED BY: Dan

An upper low over the Atlantic will slowly approach the British Isles on Thursday, with cool air aloft overspreading warm SSTs and diurnal heating inland, behind the cold front. Numerous showers will affect many western areas, occasionally feeding further inland on the southwesterly steering winds. CAPE and shear are rather weak, and so any lightning is considered to be fairly isolated. The exception to this will be Ireland, where some stronger shear may develop during the afternoon hours, helping convection to become a little more sustained. Also, an increase in instability may develop over the Irish Sea on Thursday evening and night, which may see an uptick in sporadic lightning here and over some adjacent western coasts. A low-end SLGT has been introduced to better highlight the area of interest. Given relatively low cloud bases and reasonably strong LLS, an isolated tornado / waterspout is possible.