IEM Daily Feature
Wednesday, 07 July 2021
Wednesday, 07 July 2021
Gridded Percent of Average Precipitation
Posted: 07 Jul 2021 05:48 AM
Yesterday's IEM Daily Feature discussed some of the pros and cons of using a map of contoured
point observations of precipitation percentage of average. Today's plot uses a high resolution grid
product from NOAA called MRMS and compares against an analysis of climatology based on point
observations. The resolvable detail is much higher, so an obvious question is why anybody would
want to use the courser product featured yesterday? Well, the map today is not without its own
blemishes. First up, this map is heavily based on RADAR derived estimates, which have they own
set of caveats and issues with things like wind farms and over estimates due to hail. Additionally,
confidence in these estimates decreases with increasing distance from the nearest NEXRAD site.
Having said that, the general spatial pattern nicely matches yesterday's map (which is should as they
both are generally valid maps) with very dry conditions shown near Waterloo and other places over
northern Iowa along with rather wet locations over southeastern Iowa.
Voting:
Good = 12
Bad = 1
Abstain = 1
Voting:
Good = 12
Bad = 1
Abstain = 1