UWFPS 2017 daily cold-air pool forecast valid Friday 01/27/2017 10:00 MST (10:00 am local time)

Summary: A major cold-air pool episode will begin during the afternoon Friday and continue through the middle of next week. Periods of dense fog and areas of stratus are possible during this episode, particularly in the Cache Valley and near the Great Salt Lake and will have to be carefully monitored for flight operations.

Current weather synopsis and short-term forecast for Friday 27 January:

An elevated temperature inversion was noted above 700 mb this morning:

1200 UTC KSLC sounding.

Visibility/ceiling/clouds: Mostly sunny and cold highs in the 20s, lows in the 5-10 F range. with patchy low clouds and fog in the Cache Valley and near the Great Salt Lake during the day. Ceilings expected to remain above 2500 ft AGL with visibility in the 3-5 mile range. This evening after 0300 UTC, there is a 50% chance of low stratus deck or dense fog forming in the Cache Valley, with a 30% chance in the Salt Lake Valley and 20% in the Utah Valley. Ceilings less than 500 feet and visibility less than 1/2 mile possible.

Winds: northerly, 5-10 knots.

Saturday 28 January:

Partly cloudy. Cold, highs in the 20s, lows in the 5-10 F range. 30-50% of dense fog at Salt Lake Airport and Logan Airports in the morning, 40% chance of stratus cloud deck in all basins.

Visibility/ceiling/clouds: Ceilings less than 1000 feet and visibility less than 1/2 mile possible in low clouds and fog. If this does not materialize, no visibility issues expected.

Winds: light and variable.

Sunday 29 January:

Cold-air pool conditions continue with peak temperature inversions magnitude expected Sunday and Monday (however pollutants will continue to increase through Wednesday). Partly cloudy. Cold, highs in the 20s, lows in the 5-10 F range. 30-50% of dense fog at Salt Lake Airport and Logan Airports in the morning, 40% chance of stratus cloud deck in all basins.

Visibility/ceiling/clouds: Ceilings less than 1000 feet and visibility less than 1/2 mile possible in low clouds and fog. If this does not materialize, no visibility issues expected.

Winds: light and variable. 

 

Monday 30 January:

 

Cold-air pool conditions continue with peak temperature inversions magnitude expected Sunday and Monday (however pollutants will continue to increase through Wednesday). Partly cloudy. Cold, highs in the 20s, lows in the 5-10 F range. 30-50% of dense fog at Salt Lake Airport and Logan Airports in the morning, 40% chance of stratus cloud deck in all basins.

Visibility/ceiling/clouds: Ceilings less than 1000 feet and visibility less than 1/2 mile possible in low clouds and fog. If this does not materialize, no visibility issues expected.

Winds: light and variable.

 

Tuesday 31 January - Wednesday 1 February:

Cold-air pool conditions with moderate to strong temperature inversion continue. Uncertain if the cold-pool will weaken some during this time, and if light precipitation will impact the cold-air pool. Pollutant concentrations likely increasing each day in all urban Utah Valleys. Unknown variables are 1) how much nighttime cooling occurs (clear or cloudy), 2) the amount and persistence of low clouds and fog, 3) how much mid-level clouds/light precipitation and weakening of the inversion aloft occurs toward Tuesday and Wednesday; these variables will impact the strength of the inversion during this time. Stay tuned. 

Thursday 2 February - Saturday 4 February:

Forecast models agree on a deeper storm system potentially impacting the area with precipitation and likely ending the episode in the Friday-Saturday time period.  However, forecast skill over 7-days out is low. Stay tuned.