By WeatherFlow Forecaster

This snapshot of wind observations combined with a radar image of storms moving through NJ from W to E is a good example of a gust front / outflow boundary increasing our wind speeds out ahead of approaching storms.  A gust front / outflow boundary is simply a storm scale mass of cold / cool air that descends downward within thunderstorms from high up in the atmosphere.  As this mass of cold air reaches the ground its vertical momentum transfers to horizontal momentum, which can spread out well in advance of the approaching storms that spawned the gust front.

As you compare the following two images, please note two things of interest.  First, notice how far ahead of the storms the gust front can travel.  (Hook, Brick, Kite Island and even Tuckerton)  Second, directions at N sites are westerly due to the gust front and directions at S sites remain southerly as they were too far away from the storms at the time of the snapshot to have there conditions affected.

Gust Front Outflow Boundary Radar

Gust Front Wind Observations



Posted by WeatherFlow meteorologist Dave Breckenridge