Pea-sized hail at work

Around 13:10 today (2006-10-02), a small cell producing pea-sized hail passed over the Northrop Grumman facility here in Fort Wayne. I estimate about 5-10 stones accumulated per square foot.

Earlier in the day (around 10:40) an intense line of thunderstorms passed through the area, with frequent cloud-ground lightning. Rainfall has been briefly intense in these thunderstorms, but so far less than 0.4" has been received (at home & work).

The radar loop shown here covers the period 10:03 to 13:17. Of particular note is the thin outflow boundary… the arc of precipitation along the south and southwest of the main rain area that sweeps steadily ahead of that area. Outflow boundaries are only occasionally strong enough to produce precipitation; this is a classic example of one that does.

Although the overall movement of the rain area is southward, note that individual cells (once propagated) move easterly. It is only the "trigger line" that is moving steadily southward.

As you can see from the surface map, this area of rain is isolated. There is no surface or upper-level low associated with it. Also, it is fairly cool; the temperature (and dewpoint) have remained in the upper 50s throughout the day.

images from www.wunderground.com
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awc 2006-10-02 13:27:23