Convective Outlook: Tue 21 Jun 2016
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Tue 21 Jun 2016 - 05:59 UTC Wed 22 Jun 2016

ISSUED 18:02 UTC Mon 20 Jun 2016

ISSUED BY: Dan

Sharpening upper trough over the Atlantic, but with rising heights / weak ridging over the British Isles, suppressing deep convection in many areas. However, greater proximity to the upper trough will allow some convective potential across portions of Scotland, Northern Ireland and Ireland. Here, scattered showers / outbreaks of showery rain are likely to affect western extremities in particular, but overall the environment does not look particularly conducive to producing lightning. Chances increase more in the evening hours as lapse rates steepen a little due to an advancing shortwave and marginal cooling aloft, but by this stage peak heating will have passed and so given the very low potential for lightning, have refrained from issuing any threat levels for now.


As the upper trough continues to sharpen and dig southwards towards the west of Iberia, the resultant backing flow will lift a warm front (which will be straddling northern France on Tuesday) northwards across southern counties of England through the early hours of Wednesday, associated with advection of a high WBPT airmass into S/SE Britain by Wednesday morning. This may bring some better potential for deep convection later on Wednesday and into Thursday, for which other forecasts will be issued if necessary.