Mountain Weather Forecast

Time and Day: 0715 Saturday

The Snapshot:  Partly sunny with increasing clouds and dry today, mostly sunny tomorrow. Strong temperature inversion with cold temperatures in the base area today.  

The Science: High pressure over the West Coast is providing mild conditions in the Pacific Northwest. Upper level air temperatures have moderated considerably, with upper mountain weather stations showing 32 degrees. A large difference in sea level pressure between the East and West side of the crest is driving easterly flow through the passes, reflected in the 8 degree temperature reading in the base area! A weak low pressure system will ride up and over the ridge today, with the main effect being increasing clouds throughout the day. The ridge should rebuild Sunday for another dry and mild day.

The Long Range: Things begin to get interesting Monday as strong SW flow begins to affect the PNW. Increasing clouds and warming temperatures will be seen during the day Monday, but the precip should hold off until Monday evening. There is currently little in the way of east flow indicated to insulate Stevens Pass from this rain event. Once it starts, the ride continues through Wednesday with heavy rain, strong SW winds, and freezing levels around 6-7,000 feet. The good news is that currently the second half of next week looks to include a return to snow. Stand by on details about that.

Precipitation Ending at 4am: Today 24hr water = 0 Snow = 0 Tomorrow’s 24hr water =  0 Snow = 0 Trend and Timing: No precipitation is expected today or tomorrow.

24hr temperature ending at 4 am tomorrow:                                        Low: 7 (in the base area)    High: 34 (on the upper mountain) Freezing level: 5,000 Trend and Timing:    The free air freezing level (unaffected by topography) will be around 5,000 today, the easterly flow through the passes will keep temperatures well below 32 from mid-mountain down.

24hr Winds (mph) ending at 4 am tomorrow: Base: E 5-10 Ridge Top: variable 10-15 Trend and Timing:  Winds should remain moderate from the east today. Wind direction at ridge tops will likely fluctuate as the weak low pressure approaches our area. DV