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Avalanche forecast for roads in Iceland
Magni Hreinn Jónsson
Åndalsnes, 2017
Monitored roads
• Three monitored roads
• Avalanche forecast made
daily by IMO for the road
administration (IRCA)
• IRCA informs travellers,
issues warnings and closes
roads
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Monitored roads
• Kirkjubólshlíð:
• ~4 avalanches every winter
• In 1-2 cycles
• Súðavíkurhlíð:
• ~27 avalanches every winter
• In ~7 cycles
• Average daily winter traffic: 367 vehicles
• Avalanche forecast since 2013
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Population: 4516
Population: 186
Monitored roads
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• Siglufjarðarvegur:
• ~4 avalanches every winter
• In 4-5 cycles
• Average daily winter traffic: ~200 vehicles
• Avalanche forecast since 2014
• Ólafsfjarðarvegur:
• ~8 avalanches every winter
• In ~5 cycles
• Average daily winter traffic: 368 vehicles
• Avalanche forecast since 2013
Population: 1994
Population: 1348
Súðavíkurhlíð
Monitored roads
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Siglufjarðarvegur, photo: Oddur Sigurðsson
Avalanche forecast
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• Based on statistical analysis of recorded
avalanches and weather measurements
• Likelihood of avalanches for given:
• Wind, Temperature and Precipitation
• Other factors have to be evaluated by the
forecaster:
• Avalanche activity
• Snow depth
• Snow drift
• Snowpack stability
• Etc.
Avalanche forecast
Predefined danger levels:
1. No/minor avalanche danger
within the next 24 hours.
2. Possible avalanche danger
within the next 24 hours.
3. Considerable avalanche danger
(10-40% probability).
4. High avalanche danger (more
than 40% probability).
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Avalanche forecast
Predefined danger levels:
1. No/minor avalanche danger
within the next 24 hours.
2. Possible avalanche danger
within the next 24 hours.
3. Considerable avalanche danger
(10-40% probability).
4. High avalanche danger (more
than 40% probability).
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Súðavíkurhlíð and Kirkjubólshlíð
Avalanche forecast
Predefined danger levels:
1. No/minor avalanche danger
within the next 24 hours.
2. Possible avalanche danger
within the next 24 hours.
3. Considerable avalanche danger
(10-40% probability).
4. High avalanche danger (more
than 40% probability).
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Ólafsfjarðarvegur
Avalanche forecast
Predefined danger levels:
1. No/minor avalanche danger
within the next 24 hours.
2. Possible avalanche danger
within the next 24 hours.
3. Considerable avalanche danger
(10-40% probability).
4. High avalanche danger (more
than 40% probability).
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Siglufjarðarvegur
Avalanche size
…possible avalanches will most
likely be small and should not
reach the road. Conditions are
considered to be at upper limit
of danger level 1.
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Avalanche size
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Avalanche size
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...danger level 1 due to little
snow in gullies...
Monitoring cameras
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Danger level 3 the day before
Danger level 4
Monitoring cameras
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Danger level 1
Warnings and closures
IRCA makes decisions about road closures and issues warnings
Road users can sign up to receive text messages with avalanche warnings for
Súðavíkurhlíð
Started for Ólafsfjarðavegur last winter
Predefined messages:
A. Súðavíkurhlíð: Avalanche hazard possible later today, Wednesday
B. Súðavíkurhlíð avalanches: Alert status is declared today, Wednesday at 11 AM
C. Súðavíkurhlíð avalanches: Danger status is declared today, Wednesday at 12
AM. The road is closed.
D. Súðavíkurhlíð avalanches: Danger status is called off Thursday at 17:30. The
road is open.
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Avalanche defenses
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Avalanche defenses
Ólafsfjarðarvegur, photo: Sveinn Brynjólfsson
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Avalanche defenses
Ólafsfjarðarvegur, photos: Sveinn Brynjólfsson
Conclusion
• Avalanche forecast aims to reduce traffic when the
avalanche danger is increased
• Planned road closures to reduce inconvenience
• …and for safety
• Text messaging service will be started formally this
winter for Ólafsfjarðarvegur
• Improve the forecast to get better consistency between
the roads
21Ólafsfjarðarvegur, photo: Oddur Sigurðsson
