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The VLab Forum will occur at 3:00 - 4:00 PM (EST) and features a
presentation titled "Advancing Probabilistic Snowfall
Prediction in the Mountain West and Beyond". The talk is being
given by Jim Steenburgh who is a professor in the Department of
Atmospheric Sciences at the University of Utah in Salt Lake City,
UT. We hope you can attend.
To participate in the forum, please register
for the webinar.
Abstract:
Winter precipitation poses a major challenge for operational
weather forecasting and frequently leads to snow- or ice-bound
traffic, air-travel disruptions, vehicle accidents, power outages
and infrastructure damage. During winter storms, the difficulties of
quantitative precipitation forecasting are compounded by the need to
also consider factors such as precipitation type, snow-to-liquid
ratio, snowfall rate and amount, snow level, and wind transport.
This talk describes one approach for generating high-resolution,
medium-range snowfall forecasts over the contiguous western United
States where topographic effects strongly modulate precipitation
type and snow-to-liquid ratio. The approach involves downscaling
ensemble precipitation forecasts from the ECMWF Ensemble (ENS) and
the NCEP Global Ensemble Forecast System (GEFS) to 800-m grid
spacing using climatological PRISM precipitation analyses and then
applying a machine-learning algorithm trained with data collected by
snow-safety (i.e., avalanche control) teams at mountain sites
through the western US to forecast snow-to-liquid ratio. The result
is an 82-member ensemble snowfall forecast that we call the Utah
Snow Ensemble and provides probabilistic guidance for precipitation,
snowfall, snow level, and snow-to-liquid ratio (see
https://weather.utah.edu/index.php?runcode=2024102500&t=ensgefsds&d=6HS&r=WE
and links for other products in the left menu bar).
The Utah Snow Ensemble serves as our testbed for predicting
snowfall and snow properties over the western US. We are also
producing CONUS-wide forecasts of snowfall and snow-to-liquid ratio
based on training with CoCoRAHS observations. These will be
discussed if time permits.
Agenda:
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Slides:
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