ISSUED: Monday January 12, 2025 11:00 MST

SYNOPSIS: A large Pacific system will continue eastward across southern BC with further precipitation (rising snow level) and significant wind at times today, tonight and early Tuesday.  A strong upper ridge of high pressure building northward from California-Oregon should allow for partial clearing Tuesday afternoon and Tuesday night. The temperature should continue to gradually trend milder.

FREEZING LEVEL: Rising to near 1700-1800 metres this afternoon, trending higher tonight.  Rising above 2000-2200 metres Tuesday.

FERNIE ALPINE RESORT FORECAST (1615 metres):

TODAY: Cloudy with fog patches and occasional snow/rain. Snow level 1500-1700 metres, accumulation from 4 to 8 cm.  Windy, possibly strong at times.  High near 1.

TONIGHT: Rain/snow, possibly heavy at times.  Snow level 1600-1900 metres, possibly higher overnight. Possible 20 mm/cm.  Windy at times.  Low 0 or 1, possibly milder overnight.

TUESDAY: Mainly cloudy with fog patches and a 60% chance of light rain during the morning.  A mix of sun & cloud developing during the afternoon.  High 3 or 4.

TUESDAY NIGHT:  Clear with cloudy periods, possible fog and low cloud developing overnight. Low near -1.

OUTLOOK:

WEDNESDAY: Possible low cloud and fog patches, otherwise sunny with afternoon cloudy periods. Increasing wind during the afternoon. High near 4.  Low -1 or -2.

THURSDAY: Possible low cloud and fog patches, otherwise mainly sunny. High 2 or 3.  Low -2 or -3.

FRIDAY: Possible low cloud and fog patches, otherwise mainly sunny. High near 2. Low near -3.

CONFIDENCE/DISCUSSION: Fair to good confidence of the synoptic pattern, still poor to fair confidence of the local details.  Accurately predicting the local amounts of precipitation and the snow level during the next 18 to 24 hours is the main challenge.  Some guidance favours tonight for the heavier band of precipitation (exactly how heavy is questionable) while others suggest a greater than currently predicted amount today. The temperature and snow level have been slow to rise so far and the snow level could remain near 1600 metres today.  All of the guidance trends the snow level higher tonight, possibly up to 2200 metres. A weak upper trough skirting north of Fernie could result in cloudy periods or a few bands of cloud and increased wind Wednesday afternoon.  Otherwise a very strong upper ridge of high pressure should dominate Tuesday afternoon through Saturday.  A deep temperature inversion and stagnating low level airmass make for some uncertainty of the local sky condition and temperature, extensive low cloud and fog are possible.

Ron Lakeman.