|Alpine Weather Report|
ISSUED: Monday December 11, 2017 9:45 MST
SYNOPSIS: Temperatures should trend slightly higher today (especially at ridgetop elevation) as a temperature inversion strengthens over the area. Otherwise, the pattern remains largely unchanged with a strong ridge of high pressure maintaining dry and stable conditions and patchy valley cloud and fog at low/mid elevation. Bands of moisture drifting through the upper ridge should bring increasing high cloud on Tuesday above the fairly stable valley cloud. Expect cooler temperatures at upper elevations due to reduced surface heating Tuesday afternoon. Sub-zero temperatures are expected at all elevations Tuesday night.
FREEZING LEVEL: Above freezing layer between roughly 1800m and 3300m this afternoon. Near or slightly above freezing layer between roughly 2000m and 3500m tonight and early Tuesday. Cooling below zero at all elevations by Tuesday afternoon. Surface Tuesday night.
FERNIE ALPINE RESORT FORECAST (1615 metres):
TODAY: Patchy low cloud or fog below roughly 1600m with partial clearing possible in the afternoon. Mainly sunny above. Risk of a few snowflakes falling from local low cloud. High near -2 at 1600m; near 3 at ridgetop elevation.
TONIGHT: Mainly cloudy with fog patches between roughly 1300m and 1500m; mainly clear above. Risk of a few snowflakes falling from local low cloud. Low at 1600m near -8; near zero at ridgetop elevation.
TUESDAY: Cloudy with low cloud and patchy fog below roughly 1600m. Increasing high cloud above. High near -4; steady near zero or else cooling to near -2 through the day at ridgetop elevation.
TUESDAY NIGHT: Mainly cloudy. Low at 1600m near -8; near -6 at ridgetop elevation.
WEDNESDAY: Cloudy with fog patches and possible sunny breaks. High near -2. Low near -8.
THURSDAY: Cloudy with fog patches and possible sunny breaks. High near -2. Low near -6.
FRIDAY: Cloudy with occasional snow, light accumulation. High near -3. Low near -6.
CONFIDENCE/DISCUSSION: Fair to good confidence in the continued dry and stable pattern through Thursday. For ridgetop elevation, peak warming with this strong upper ridge should occur this afternoon. Peak warming at the Main Plot elevation should also occur this afternoon but local low cloud and a strong vertical temperature gradient make for a trickier temperature forecast at mid elevations. Tough call on the timing and thickness of approaching high cloud on Tuesday. Peak ridgetop temperatures on Tuesday may occur late morning or early afternoon. High pressure should maintain generally dry and stable conditions through Wednesday and Thursday before the first of a series of increasingly moist Pacific frontal systems brings an end to the current dry spell with a few flurries or occasional snow on Friday. The energy & moisture content of the first storm to push through a blocking upper ridge is often over-forecast. Up to 5cm is expected Friday, potentially followed by double that or more this weekend.