Thursday, July 5, 2012


Yup, stuff is falling from the sky, including at the Salt Lake City International Airport.  The latest radar shows that it is especially active out along the Utah–Nevada border.
Source: NCAR/RAL
These showers stem from a surge of monsoon moisture. In the loop below, the wind vectors show the jet-stream level flow over the past few days through this afternoon (the latter frames being a forecast), while the contours show the precipitable water, the depth of water you would have if you condensed out all the water vapor in the atmosphere.  Note the penetration of higher precipitable water values into northern Utah as the jet-level flow became more southerly and tapped into moisture over northern Mexico and Arizona.

Observations from the Salt Lake International Airport show the dramatic increase in precipitable water since early in the morning on July 4.  We currently sit just above an inch, which is pretty high for northern Utah in July.  

The dewpoint was 50ºF this morning as well.  Bad for swamp coolers, but good for the skin.  Lower temperatures and higher dewpoints should also help firefighters today.  Let's hope there aren't any additional lightning starts or strong microburst winds.

1 comment:

  1. It looks like our current monsoon surge is associated with a tropical wave that developed near the coast of south Texas over a week ago, about the same time that tropical storm Debby was affecting Florida. It is interesting to try to trace the history of it in the GFS.