I signed up as Dockmaster the night before since no one else had. We had a decent turnout, with 21 people showing up. There was a Severe Thunderstorm watch in effect, and there had been a severe thunderstorm roll through about an hour and a half before the sail, but the sky was only partly cloudy, with no significant storms reported, though there were some radar contacts of some concern near the Maryland-West Virginia border, southwest of Baltimore. I advised everyone to stay relatively close to the docks in case the weather turned for the worse.
Kelly and I took out a J/22. I let her man the helm while I monitored the weather. After 15 minutes after departure, I saw that the radar contacts I had noticed earlier had not dissipated as they moved east as I had hoped, so I notified everyone over the radio that a possible storm cell was forming. I checked again about 15 minutes later, and saw that the radar contacts were heading toward Baltimore, so I advised that anyone who had rain gear should don it immediately. 15 minutes after that, I saw that a hail/thunderstorm had been reported in the vicinity near Columbia, MD, and that the storm track was clearly heading toward Baltimore. I notified everyone over the radio of this situation. Around the same time, some people saw distant lightning, and all of the boats made their way toward the docks.
As we were de-rigging, we encounted some light rain, and could hear distant thunder. However, as it turned out, the storm broke up prior to arriving in Baltimore.