Warnings about rains causing flooding
Warnings about heavy rains pertain to rains of both short and long duration. Heavy rains causing flooding occur in Finland mainly from spring to autumn.
The heaviest rains are usually recorded in late summer, when local 24-hour precipitation readings can exceed 100 millimetres.
Separate warnings can be given for heavy rains of long duration and for downpours of short duration. However, short-duration rains are associated with quickly developing thunder clouds that are more difficult to predict than extensive rain areas.
Rain warnings use three warning limits:
- Warning about heavy rain of long duration: warning limits 50, 70 and 120 millimetres per 24 hours
- Warning about a downpour of short duration: warning limits 20, 30 and 45 millimetres per hour.
Early warnings on heavy rains are also issued as much as three days in advance. Whenever necessary, the warnings are updated twice a day by 4:00 a.m and 3:00 p.m.
Warnings on heavy rains have been issued since May 2009.
Aside from the Finnish Meteorological Institute’s website, heavy rain warnings are read in connection with the Finnish Broadcasting Company’s (YLE) weather forecasts.
Check the warnings in force on the warnings page. Read more about early warnings, which are also issued on heavy rains.
Photo: A Halas.