I didn't chase the Ft. Lupton/Hudson/Prospect Valley storm. However, the core passed directly over my house in Firestone, so I got a good taste of it nonetheless.
Initially, I was expecting to miss out on the action, as the original storm which had been hugging the Boulder/Larimer County as it drifted east looked to pass just north of my location. However, the second storm literally exploded two or three miles west of me. It went from nothing to 55 dBZ core in something like two volume scans. I remember looking at the storm's radar presentation and then looking out the window to see the core literally hanging above me and thinking, "We're about to get hammered."
And that's exactly what happened. The rain and hail began at pretty much the same time. Massive amounts of marble size hail, driven by winds in the 45-55 mph range (with higher gusts), were being "machine gunned" against the side of the house and the window out which I was watching. The roar was so loud I couldn't even hold a conversation with someone. From my second floor perch, I had a view of a section of first floor rooftop, and the hail was accumulating so rapidly that giant sheets of ice were sliding down the incline and jamming the gutters. The street out front (when I could actually see it) was a flowing river of water and ice all the way up to the curb.
I've found myself in some pretty intense cores in the past when out chasing, but never have I seen this much hail falling at such an incredible rate in such a short window of time. It probably only lasted for 3-4 minutes, but when I stepped outside afterward to take a look, the hail had accumulated and drifted to 6" deep in spots. It looked as if it had snowed.
(And, on an interesting note, here it is the next morning, 16 hours later, and the deepest drifts have yet to completely melt.)
Anyway, after shooting some photos and playing in the hail, I decided to take another look at the storm... only to see something interesting. My initial thought was, "That looks like the back side of a tornadic supercell." It just had "the look". There was an obvious rain and hail shaft wrapping around the back side of the updraft, the edge of a rain free base peeking out from the trees to the south, and a lot of curious motion. I asked myself, "Is this thing going to tornado?", and before I could even complete my thought, the tone alert went off on the NWR with the first of the many tornado warnings, mentioning the apparent tornado near Ft. Lupton - exactly where I was looking.
Of course, being on the back side of the storm, I couldn't see anything, but I continued to watch. The storm maintained "the look" for as long as I was watching, in fact. For all I knew, there could have been a rain-wrapped tornado somewhere in there. However, the storm was accelerating somewhat by this point, and it wasn't long before my view was blocked by trees and houses. I never gave any serious consideration to jumping in the car and giving chase... it would have taken too long to reach Hwy. 52, and I didn't have much interest in punching the core in a desperate attempt to get out ahead of the storm. By that point, the core was just looking more intense on radar, and Tony's report of golf balls would seem to verify that.
Either way, in a year where I'm unable to take a chase vacation (and generally too busy to do much local chasing), it was nice to have the storm of the day pay a visit to me here at home.
