As the sharp upper trough digs across Iberia, on the forward side continued gradual warm air advection is likely from the nearby Continent and across southern and eastern Britain. Mid-level lapses will steepen, which combined with the passage of a northward-moving shortwave (arriving late afternoon over the English Channel, and reaching Shetland towards Tuesday morning) will encourage some elevated convection to develop during the evening and night hours, spreading northwards - generally from the Isle of Wight to Cumbria, and points east of there. Weak instability and rather saturated profiles suggests lightning is rather unlikely, but some showery bursts of rain will be possible.