The Elusive Freezing Level Page

This page may be helpful to people searching for information regarding the current and forecast freezing levels across Southern BC. The profiles come from a computer model of the atmoshphere known as the MM5, run at Washington State University. This model is run twice a day and new forecasts from each run are available at about 8am and 8pm PST. Most of the profile locations are in Washington State but a few are in Southern BC:

Victoria
Kelowna
Comox
Vancouver

Time

Time runs from RIGHT TO LEFT along the x-axis in 6-hour steps out to 72 hours from initialization. Time is referenced as UTC which is 8 hours ahead of PST. For example: The early run of the model is initialized at 12 UTC (or 4am PST). The later run of the model is initialized at 00 UTC (or 4pm UTC).

Elevation

Elevations are along the y-axis and are given by pressure-level. The following are the conversions of pressure-level to elevation in a standard atmsophere:

1000 mb = roughly sea-level
950 mb = 500 metres
900 mb = 1000m
850 mb = 1500m
800 mb = 2000m
750 mb = 2500m
700 mb = 3000m

The Freezing Level

The freezing level ( thw zero-degree isotherm)is identified by the roughly horizontal red-line marked '0' that runs across the graph. Trends can be clearly identified as time advances into the future 72 hours.