Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts
ABSTRACT For 175 difficult-to-forecast persistent deep slab avalanches, weather data were obtained from Global Environmental Multiscale (GEM) models produced by Environment Canada. The focus was to determine critical parameters and thresholds for avalanche forecasting from GEM and compare them with...
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Online Access: | http://dx.doi.org/10.1017/jog.2016.2 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000022 |
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crcambridgeupr:10.1017/jog.2016.2 2024-03-03T08:46:09+00:00 Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts CONLAN, MICHAEL JAMIESON, BRUCE 2016 http://dx.doi.org/10.1017/jog.2016.2 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000022 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 62, issue 232, page 256-269 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.2 2024-02-08T08:46:40Z ABSTRACT For 175 difficult-to-forecast persistent deep slab avalanches, weather data were obtained from Global Environmental Multiscale (GEM) models produced by Environment Canada. The focus was to determine critical parameters and thresholds for avalanche forecasting from GEM and compare them with weather station data analyzed in Part I (Conlan and Jamieson, this issue). The high-resolution GEM-limited-area model (2.5 km resolution) forecasted higher median precipitation amounts than both the lower-resolution GEM15 (15 km resolution) and weather stations within a small dataset. Air temperatures were lower for both weather models compared with the weather station data, likely because of elevation differences. A multivariate classification tree created with GEM15 data correctly classified 29 of 36 avalanches by their primary cause-of-release, using a primary split of modelled solar warming of 5.9°C, 10 cm into the snowpack. For all 175 avalanches, GEM15 forecasted significantly less precipitation than observed at the weather stations, particularly with multi-day cumulative amounts. The majority of GEM15 surface wind speeds were between 0 and 10 km h −1 , producing negligible wind loading amounts. The parameter values may be helpful for predicting future persistent deep slab avalanches. However, GEM output is not always representative of field conditions and should be used in conjunction with other sources. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Canada Journal of Glaciology 62 232 256 269 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes CONLAN, MICHAEL JAMIESON, BRUCE Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts |
topic_facet |
Earth-Surface Processes |
description |
ABSTRACT For 175 difficult-to-forecast persistent deep slab avalanches, weather data were obtained from Global Environmental Multiscale (GEM) models produced by Environment Canada. The focus was to determine critical parameters and thresholds for avalanche forecasting from GEM and compare them with weather station data analyzed in Part I (Conlan and Jamieson, this issue). The high-resolution GEM-limited-area model (2.5 km resolution) forecasted higher median precipitation amounts than both the lower-resolution GEM15 (15 km resolution) and weather stations within a small dataset. Air temperatures were lower for both weather models compared with the weather station data, likely because of elevation differences. A multivariate classification tree created with GEM15 data correctly classified 29 of 36 avalanches by their primary cause-of-release, using a primary split of modelled solar warming of 5.9°C, 10 cm into the snowpack. For all 175 avalanches, GEM15 forecasted significantly less precipitation than observed at the weather stations, particularly with multi-day cumulative amounts. The majority of GEM15 surface wind speeds were between 0 and 10 km h −1 , producing negligible wind loading amounts. The parameter values may be helpful for predicting future persistent deep slab avalanches. However, GEM output is not always representative of field conditions and should be used in conjunction with other sources. |
format |
Article in Journal/Newspaper |
author |
CONLAN, MICHAEL JAMIESON, BRUCE |
author_facet |
CONLAN, MICHAEL JAMIESON, BRUCE |
author_sort |
CONLAN, MICHAEL |
title |
Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts |
title_short |
Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts |
title_full |
Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts |
title_fullStr |
Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts |
title_full_unstemmed |
Naturally triggered persistent deep slab avalanches in western Canada Part II: weather trends from model forecasts |
title_sort |
naturally triggered persistent deep slab avalanches in western canada part ii: weather trends from model forecasts |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/jog.2016.2 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000022 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 62, issue 232, page 256-269 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2016.2 |
container_title |
Journal of Glaciology |
container_volume |
62 |
container_issue |
232 |
container_start_page |
256 |
op_container_end_page |
269 |
_version_ |
1792502102398861312 |