Tihkusade

Tihkusade is a meteorological term used in Estonian to describe a light, persistent precipitation event consisting of very small water droplets that reach the ground as drizzle. It is typically considered lighter than rainfall and more continuous than a shower, and it is commonly mentioned in weather forecasts and climatological observations in northern temperate regions.

Characteristics of tihkusade include a droplet diameter usually less than 0.5 millimeters and a rainfall rate generally below 1 millimeter per hour. Visibility is often modestly reduced, with overcast skies typical of stratiform cloud decks such as stratus or nimbostratus. The precipitation falls slowly and tends to be widespread rather than concentrated in bursts.

Formation generally occurs when a shallow, moist layer near the surface is saturated and maintained by relatively uniform cooling or light ascent. This environment supports the production of many tiny droplets that coalesce or remain suspended as drizzle as they fall to the ground. Tihkusade is commonly associated with stable atmospheric conditions and persistent cloud cover.

Occurrence is frequent in maritime climates and coastal regions, and it is more common in cooler seasons. In inland areas, tihkusade can arise when fog lifts into drizzle or when shallow moist layers underlie a stable atmosphere. The phenomenon is often observed in northern Europe and other regions with similar climates.

Impact and measurement: meteorological services classify tihkusade by droplet size and intensity, using standard rain gauges and radar for observation. It tends to keep surfaces wet without causing heavy flooding, but can make roads slippery and reduce visibility for drivers and outdoor activity.

See also: mist, drizzle, rain.