IEM Daily Feature
Monday, 18 February 2013

Model Consistency

Posted: 18 Feb 2013 05:43 AM

There is currently a lot of excitement over the upcoming winter storm forecasted for Thursday into Friday. The featured chart looks at forecasted precipitation totals for Des Moines from the GFS model. The chart shows the current storm along with six recent heavy snowfall events. Each bar represents one of the four model runs made per day prior to the event. The general lack of consistency creates a creditably issue for forecasters. The top series shows one model run dumping a huge amount of precipitation and then backing off on the total up until the event. The fifth and sixth chart show going from having no precip to a storm. The caveat not illustrated here is the storm track, by which small displacements can make a huge difference in forecasted precipitation for a fixed location.

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Tags:   model   forecast