Convective Outlook: Wed 04 May 2022 |
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What do these risk levels mean? |
VALID 06:00 UTC Wed 04 May 2022 - 05:59 UTC Thu 05 May 2022
ISSUED 06:25 UTC Wed 04 May 2022
br> br>ISSUED BY: Dan
A PV anomaly will slide southeastwards across Britain during Wednesday daytime, with heights falling temporarily and cooling in the mid/upper troposphere coinciding with peak diurnal heating. The net result is the potential for much deeper convection than on Tuesday. Fairly extensive cloud during the morning, and areas of showery rain, will gradually break due to convective overturning, with an increasing risk of heavy showers evolving/developing across central and eastern England from around noon and through the afternoon and early evening. Surface temperatures of 15-17C and dewpoints 10-12C will likely yield 400-600 J/kg CAPE in a relatively narrow corridor (spatially) that will shift gradually southeastwards through the afternoon. Forecast profiles reveal skinny CAPE within a modestly sheared environment of 20-30kts as northwesterly flow aloft strengthens from the west on the rear side of the upper trough; a combination of both speed shear, as flow strengthens with height, and also some directional shear with NW-ly winds aloft and backed W or even WSW surface winds.