No Convective Activity

No thunderstorms or thundery activity is expected during the forecast period.

Watch

Severe storms are unlikely to occur, but isolated thunder, lightning or hail cannot be ruled out. Tornadoes are not expected either, although funnel clouds may be possible, depending on the nature of the forecast.

Thunder Storms

Thunderstorms with hail and possibly torrential downpours are likely to occur, sometimes quite widely in a small region. The storms can be slow moving and accompanied by gusty winds. Minor structural damage from gusty winds and small hail is possible, and a weak tornado may be possible.

Severe

Several thunderstorms with moderate hail and torrential downpours are likely to occur, affecting a wide region. The storms can be slow moving accompanied by gusty winds and maybe a tornado. Some storms may merge together into a large mesoscale convective system (MCS) or squall line. Structural damage from gusty winds, large hail and torrential rain is possible, with temporary disruption to transport and power supplies possible.

Extreme

Many severe thunderstorms with large hail and very intense downpours are likely to occur. The storms can be slow moving accompanied by very strong and gusty winds and possibly a moderate tornado. Significant structural damage from gusty winds, large hail and torrential rain is possible, with major disruption to transport and power supplies possible, which may last for several days. Extreme storms are extremely rare and are not usually forecast.