Friday, January 20, 2012

Significant Snowstorm (1/20/12)- Initial Briefing

700mb frontogenesis
We are seeing increased areas of frontogenesis across Iowa and parts of Northeast Illinois at this hour. What frontogenesis signifies is the forming of a frontal boundary of sorts. It is somewhat complicated, but in this event the bottom line is that areas with increased frontogenesis are going to get more snow out of this system. Again, we are seeing values of frontogenesis (FTG) rise in Iowa and Illinois. We can compare that with radar below.
Radar is indicating that the heaviest snow is over eastern Iowa. Based on that, it is estimated that snow will begin falling in Chicago between 10:20 and 11:30 AM CST. Depending on what factors are taken into account, these times may be shortened or lengthened.

We will have updates throughout the day on this system.
Because this is a nowcasting (forecasting as it happens) event, we will not be making a new graphic. However, the models did win in the NWS vs Models fiasco last night, so our graphic from yesterday is valid once again.

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