UWFPS 2017 daily cold-air pool forecast valid Wednesday 01/18/2017 0830 MST (8:30 am local time)

Summary: Temperature inversion has continued to descend. Pollution levels will peak today before dilution begins tonight with final mix-out of cold-air pool on Thursday with snow showers.  Low clouds cover remains over Great Salt Lake and West Desert this morning. No visibility problems are anticipated Tuesday for research flights, although southerly winds at top of inversion at flight level will increase to 15-30 kts Tues afternoon. After the current mix-out, no cold-air pools forecast through the weekend.

Current weather synopsis and short-term forecast (12-36 h forecast from Wed am 18 January-Thursday am 19th January):

Pollution levels across northern Utah basins will peak today before dilution begins tonight with final mix-out of cold-air pool on Thursday with snow showers.  

Low clouds thus far have remained confined to West Desert and Great Salt Lake regions as seen in 1400 UTC 18 Jan cloud product but were moving into the KSLC area as of 8:30 am.

There is some chance these clouds expand into the Salt Lake Valley Wednesday morning.

1200 UTC Salt Lake City sounding shows an impressive temperature inversion that continues to descend:

Forecast models begin to erode the cold-air pool late Wednesday night through the day Thursday, with complete mix-out between noon and evening Thursday expected.

Visibility/ceiling/clouds: Stratus desk over Great Salt Lake may expand into Salt Lake Valley Wednesday morning. However no visibility below 3 miles is expected. High clouds approach by mid-morning; mid-level clouds by sunset Wednesday. Precipitation starts toward dawn Thursday.

Winds: Channelled gap and southerly flow at flight level between 10-25 kts, with the stronger winds during the evening flight. Winds will be strongest at the gap between the Salt Lake and Utah Valleys.

Mid-term and Long-term forecast (Thurs-Wed 19-25 January):
 

Almost daily storms will affect the forecast area through at least Monday, January 23. Several periods of accumulating snow likely for northern Utah Valleys. More details on the timing of these storm systems will be provided in tomorrow's forecast.

  Long-range models hint at a ridge of high pressure forming over the Western US around January 25^th, but confidence is low on this pattern change this far out in the forecast cycle.