Saturday, February 4, 2012

Easterlies

Blowing snow yesterday in easterly flow on the Pfeifferhorn.
Photo: Jeff Massey
We're presently in the midst of a prolonged period of easterly flow along the Wasatch Front, with some interesting variations in the areas receiving the strong winds.

Yesterday was a beautiful day in the Wasatch Mountains, although it was strange seeing flow from the east.  This year seems like we've woken up in some sort of Bizarro world where everything is the opposite of what it should be.


The cause of all this Bizarroness is the trough that came through Wednesday and Thursday and has closed off over the interior western United States.  Yesterday the trough at 500 mb was centered over northwest Colorado with 35 knot easterly flow at 700 mb (roughly crest level) over northern Utah.


The trough deformed somewhat overnight, but the 500-mb axis still extends back over Utah and Nevada.  The 700 mb flow is  not as strong, but a strong pressure gradient is draped across the northern Wasatch with high pressure over southwest Wyoming.


Strong easterly flow has been observed at the University of Utah since about 1600 UTC yesterday.  There are two periods of peak winds, one shortly after the onset of easterlies ~1600 UTC yesterday, and the other this morning at ~1200 UTC.


In contrast, further to the north near Centerville, a site along the Union Pacific rail corridor observed the strongest easterlies earlier, from 0700-1700 UTC yesterday, with out as strong of a secondary maximum this morning.


This is a good case to examine in greater detail to better understand contrasts in the strength and timing of strong easterly flow near the University of Utah and the Centerville area.  For you atmospheric sciences undergrads, this could make a good senior thesis project.

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