New Toys

During spring break, I'm upgrading some of the products available on http://weather.utah.edu.  The latest addition is output from the North American Mesoscale (NAM) model high-resolution nest, which covers the continental U.S. at 4-km grid spacing and produces forecasts out 60 hours.  Below is the surface wind and 3-hour accumulated precipitation forecast valid for 1800 UTC (1200 MDT) this afternoon.

We'll have to keep an eye on these forecasts and see if the resolution is a help or a hindrance.  During the 2002 Olympic Winter Games, we found that the accuracy of 4-km precipitation forecasts was greater than that of those produced at 12-km, but also that the utility of the 4-km forecasts was reduced by an increase in "false alarms" (i.e., large forecast precipitation events that didn't verify).  Proceed with caution.

Stay tuned for more.