Monsoon Weakened, Not Defeated

With the passage of a weak trough and the penetration of our first (weak) gasp of flow from the northwest into northern Utah in many weeks, there's been a modest decline in humidity and clouds over the Salt Lake Valley today.  For example, the integrated precipitable water, a measure of the total water vapor within the atmosphere, declined late yesterday from just over 3 cm to something closer to 2.5 cm.

Source: NOAA/ESRL

Dewpoints at the Salt Lake City airport also declined somewhat from near 60 to something closer to the mid 50s.

Nevertheless, the monsoon is nearly weakened, not defeated, and we are still seeing some deep convection firing up over the high topography to the south and southwest of the Salt Lake Valley, especially the Oquirrh, Stansbury, and Sheep Rock Ranges.

Source: College of DuPage

Forecasting where and how strong convection of this type initiates remains a major challenge for meteorology.  For instance, why is is that the convection is deeper and more developed over the Oquirrh, Stansbury, and Sheep Rock Ranges than over the Wasatch and western Uinta Mountains just to the east?  It's impossible to anticipate such subtleties with any sort of reliability given todays forecast tools.   

Now that convection is going, monitoring it's movement and intensity will be especially challenging today due to an outage of the National Weather Service Radar on Promontory Point (KMTX).  All that is currently available is this black screen of death.  

Source: NWS

It appears that the radar has been up and down several times the past couple of days.  Hopefully the problem will be solved soon.