Canyon Winds

Our first canyon wind event of the season is underway this morning.  Unlike big downslope wind events that typically roar along much of the northern Wasatch Front, this morning stronger winds are confined to a few locals including near Weber Canyon (currently gusting to 36 mph in the canyon) and near Centerville (25 mph).

Wind and wind gust observations within one hour of 14:47 UTC (8:47 MDT).  Source: MesoWest.

There are also east winds on the University of Utah Campus and Parley's Canyon.

Wind and wind gust observations within one hour of 14:47 UTC (8:47 MDT).  Source: MesoWest.

The winds at Parley's Canyon increased at a very gradual rate overnight.  The peak gust of 49 mph occurred early this morning.

The cause of these canyons winds is an area of high pressure that slid down the east side of the Rockies and is currently centered in northwest Nebraska.  The resulting pressure gradient is driving easterly flow into northern Utah.

This easterly flow is, however, very shallow.  By the time one gets up to 700-mb (10,000 ft), the flow over the northwest portion of the state is northwesterly.

As a result, this event is confined to some of the deeper canyons (e.g., Weber, Parleys) and areas where the Wasatch Crest to the east is relatively low (e.g., the University of Utah).

The key ingredient missing from this event and preventing it from being a big, widespread downslope windstorm is a closed upper-level low centered near Las Vegas.  Such an upper-level low is needed to drive easterly flow at mountain-top level.

These east winds should slacken later this morning.