Meteorologisk institutt met.no LOKE – an extreme precipitation event in Western Norway, November 14th 2005 Anne Haaland Simonsen Met.no

Meteorologisk institutt met.no What happened? An extreme weather event in Western Norway Period of much precipitation, 602 mm in 30 days (normally 259 mm) Observed 223 mm in 24 hours SW of Folgefonna glacier (Norwegian record is 229,6 mm in same area)

Meteorologisk institutt met.no

BERGEN

Meteorologisk institutt met.no Problems caused by LOKE Closed roads Costs due to damages on the roads were approximately 4 mill. euros One person lost his life in a landslide The railway between Oslo and Bergen were closed for several days A 5 to 200 years flood in the rivers. The water level in a river between Bergen and Voss rose to what was probably a 500 year level.

Meteorologisk institutt met.no How about the models? The prognoses showed 100 to 250mm in 24 hours, EC varied between mm 4-7 days ahead. The highest amounts of precipitation varied from each model run, with the greatest intensity late Monday morning HIRLAM 5km from Sunday 00 utc showed 235 mm on 24 hours over southern parts of Folgefonna

Meteorologisk institutt met.no mm

Meteorologisk institutt met.no 100 mm

Meteorologisk institutt met.no 130 mm

Meteorologisk institutt met.no 235 mm

Meteorologisk institutt met.no Takle 12 hours accumulated precipitation for Takle (outer part of Sognefjorden). A total of 199 mm Sunday 18 to Monday 18utc. Observation is the black curve. ECMWF is olivegreen. HIRLAM.20 is blue. HIRLAM.10 is pink. UM4 is yellow.

Meteorologisk institutt met.no 12 hours accumulated precipitation for Lærdal (inner part of Sognefjorden). A total of 96 mm Sunday 18 to Monday 18utc. Observation is the black curve. ECMWF is olivegreen. HIRLAM.20 is blue. HIRLAM.10 is pink. UM4 is yellow. Lærdal

Meteorologisk institutt met.no 12 hours accumulated precipitation for Bergen. A total of 135 mm Sunday 18 to Monday 18utc. Observation is the black curve. ECMWF is olivegreen. HIRLAM.20 is blue. HIRLAM.10 is pink. UM4 is yellow. Bergen

Meteorologisk institutt met.no 12 hours accumulated precipitation for Sauda (northern Rogaland). A total of 107 mm Monday 06 to Tuesday 06 utc. Observation is the black curve. ECMWF is olivegreen. HIRLAM.20 is blue. HIRLAM.10 is pink. UM4 is yellow. Sauda

Meteorologisk institutt met.no StationFylke14. Nov utc 15. Nov utc Total OpstveitHordaland-223,0 TakleSogn og fjordane111,4115,1226,5 HellansbygdRogaland75,0107,2182,2 LavikSogn og Fjordane74,399,5183,8 BjørheimRogaland17,6145,7163,3 HundseidRogaland45,0114,6159,3 HovlandsdalSogn og Fjordane89,567,8156,3 Nedre VatsRogaland32,6117,5150,1 Bergen - FloridaHordaland61,588,2149,7

Meteorologisk institutt met.no Extreme Forecast Index (EFI) from ECMWF Saturday 12 November 2005 at 06UTC. Valid Monday 14 November 06UTC to Tuesday 15 November 06UTC

Meteorologisk institutt met.no Conlusion The prognoses were relatively good in this situation Made it possible to be out early with an extreme weather warning

Meteorologisk institutt met.no In what kind of situations could we expect such large amounts of precipitation? Position of high pressure –Normally around 50 degrees north - With an east–west orientation –Warm, humid air is transported north because of the high and then eastwards with the low activity on the north side of the high pressure Time scale of development –If the devolpment is too rapid, the cold front is passing to fast and the most intensive precipitation is of a short duration

Meteorologisk institutt met.no Any questions?

Meteorologisk institutt met.no Extreme warning in Norway When there’s a risk that the weather will cause a danger for lifes and values. Strong wind, heavy precipitation, extreme risk of avalanche, extreme flooding Also dependent on the area An extreme weather warning is sent out during the 72 hours before the event. When there is less than 48 hours until the event, the warnings are updated every six hour. During the event new warnings are sent out every 3-6 hours. The warnings are sent to Ministry of Justice, regional commissioner, the police, local authority, media.