Convective Outlook: Tue 21 May 2019

LOW SLGT MDT HIGH SVR

What do these risk levels mean?

Convective Outlook

VALID 06:00 UTC Tue 21 May 2019 - 05:59 UTC Wed 22 May 2019

ISSUED 20:37 UTC Mon 20 May 2019

ISSUED BY: Dan

Upper low to the west of Scotland will gradually drift southeastwards across Scotland during Tuesday. The resultant cool air aloft will steepen mid-level lapse rates, which combined with diurnal heating should yield 300-500 J/kg CAPE. A cloudy start with outbreaks of rain over the area should break up as convective-overturning takes place, with scattered showers developing by the afternoon, persisting well into the evening / overnight as the upper low moves slowly across the area. Flow is a little weak, but there is some speed and directional shear. As such, a few sporadic lightning strikes will be possible - particularly over Sterlingshire, Perthshire and Fife, and environs. Confidence is not high enough to warrant a SLGT at this stage.