Convective Outlook: Sun 16 Feb 2020
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Convective Outlook

VALID 06:00 UTC Sun 16 Feb 2020 - 05:59 UTC Mon 17 Feb 2020

ISSUED 20:53 UTC Sat 15 Feb 2020


A dual cold front will be slowly clearing southeastwards across England and Wales on Sunday morning, within a strongly-sheared environment. The frontal boundaries are likely to exhibit marked temperature and wind speed gradients and wind veer. One or two well-pronounced bands of line convection are expected to develop, producing a narrow zone of very heavy rain and perhaps some gusty winds. In general the shallow nature of convection coupled with saturated profiles and weak instability suggests the risk of lightning is fairly low. Nonetheless, should line convection fracture or evolve into an LEWP, perhaps with interaction with local topography, an isolated tornado may be possible.

Behind the frontal rain, cold air will overspread relatively warm SSTs to generate 300-500 J/kg CAPE in an environment with steep mid-level lapse rates. Numerous showers will develop over open waters and feed inland across Scotland and Ireland, occasionally organised into more distinct bands as shortwaves move through in the flow. Showers will also feed into England and Wales from Sunday afternoon onwards. Some sporadic lightning will be possible in some of the showers, primarily close to western coasts since instability will be maximised just offshore. Strong shear across the southern half of the British Isles may allow some cells to become organised, capable of producing hail up to 1.5cm in diameter and strong gusts of wind (up to 70-80mph in exposed locations) - an isolated tornado cannot be ruled out.