Melting snow expected to bring spring floods to south of Finland

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Rising temperatures and rain are likely to bring flooding to the south of Finland in the coming weeks, with some rivers already overflowing their banks.
      The flood warning system of the Finnish Environment Institute (SYKE) reported elevated water levels in a number of locations. However, much worse is expected to come.
     
The most serious problems on Sunday were limited to high water from melting snow on roads, the yards of homes, and parking areas.
      For instance, in Lahnus in the north of Espoo, water rose onto the Vihti highway, flooding the bicycle and pedestrian path, a bus stop, and one lane of the highway.
      “This happens every spring”, said Anja Tiljander who had to cut short a walk she was taking with her dog. “All the drains are clogged. The water will not fit in them."
     
Water flow in rivers is expected to increase in the south of Finland this week, and should peak in mid-April.
      In Ostrobothnia in the west of Finland, spring flooding is expected to start about two weeks later, and Finnish Lapland is likely to experience the same situation in late April or May.
     
The biggest floods are expected along the south coast, says SYKE hydrologist Bertel Vehviläinen.
      Most rivers along the south coast are expected to have significantly higher water this spring than has been the norm in the past decade.
     
Sunday’s rain accelerated the melting of the snow in the south of Finland. Showers are also expected today, Monday, and on Wednesday this week.
      Vehviläinen says that the prevailing weather during the spring thaw will be decisive in determining the extent of the flooding. If the melting of the snow is accompanied by heavy rain, it would sharply increase the water flow. On the other hand, low temperatures would slow the melting, and extend the flooding over a longer period, avoiding a single surge of high water.
      If the arrival of spring is delayed, the risk of big floods later could grow, if more snow accumulates.
     
SYKE is not yet predicting the extent of flooding in Finnish Lapland. The larger-than-average amount of snow in Ounasjoki is bringing a flood risk to Kittilä, but Vehviläinen sees no cause for concern at this point.
      The spring high water is expected to be about average for Finnish Lapland this year.
      Water levels in the Saimaa waterway in the southeast, and Lake Päijänne in the south are currently lower than average, and are expected to reach average levels later.


Previously in HS International Edition:
  Here to stay? Snow cleared from capital area´s streets and public places may not melt before next winter (10.3.2010)
  GUEST COLUMN: Winter mayhem could be reduced by listening to researchers (9.3.2010)

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