The Thunderdome

The Thunderdome

  • By: Skip Morris
  • Photography by: Skip Morris
The Thunderdome

Recently i delved online, then perused my substantial fly-tying library, trying to find some sort of attractor-emerger fly pattern. I failed, and that surprised me—there are thousands of attractors and emergers in existence, but those are all nymphs, streamers or dries. Never a combination of the two.

Morris’ Thunderdome (purple)

  • Hook: Light wire, humped shank, sizes 10 to 18
  • Thread: Purple 8/0 or 6/0
  • Shuck: One strand of pearl Flashabou or a short, thin clump of pearl Angel Hair
  • Rib: Fine red or silver wire (I like Ultra Wire in XSM)
  • Abdomen: Purple Flashabou or Krystal Flash
  • Parachute wing: Yellow, chartreuse, orange or pink wool or egg yarn
  • Hackle: Brown
  • Down wing: Tan, light gray, white or cream wool
  • Thorax: Purple natural or synthetic buoyant dubbing (I use cream dubbing and turn it purple with a permanent marker)

I took that research to the tying bench and tested my curiosity by creating the Thunderdome—its dubbed thorax, hackle, buoyant downwing and brightly colored upturned eye hold everything on the surface; its looped tail shuck and bright metallic abdomen are slightly submerged, in the posture of an emerger. In my mind, it was about time somebody tried this combination. Here’s why: Attractors often outfish imitative flies, sometimes impressively. That’s no longer a theory but a fact, and the right circumstances for an attractor are simple to recognize—whenever imitative flies aren’t moving trout, which can be about any time insects aren’t hatching in significant numbers. In addition, there’s the problem of buoyancy, specifically a frustrating lack of it in modern emerger patterns. That’s because emergers imitate insects that are half-sunken, getting ready to leave the water. CDC and deer hair blended into emerger patterns help them float, but the buoyancy of both materials is short-lived. Riding low, those patterns may also be difficult for an angler to spot. The Thunderdome, however, floats for a long time and is easy to see, thanks to a downwing and a bright, fuzzy top of stubbornly buoyant wool.

Thunderdome 1.Admittedly, buoyancy was a problem during the early stages of the Thunderdome, too. The trout liked this fly right off the bat, but I grew weary of trying to keep it afloat. I’d been working with wool in a caddis/stonefly imitation I call the Woolly Wing, and the stuff floated its heart out. So I added a wool wing to the Thunderdome, a wing that lay horizontal, right down on the water. Problem solved. All of a sudden I could bounce the Thunderdome down one choppy run after another without its sinking.

Thunderdome 2.And the trout responded. In fact, recently I was tenkara fishing on a small Washington-state trout stream with a size 14 purple Thunderdome below that peculiar braided tenkara line, teasing quivers into the fly as it rode the pools and pockets. The little rainbows smacked it with delight. But it’s not only for small fish—I’ve watched 15- to 18-inch cutthroat drift lazily up to sip in black, gold and green versions; and I’ve seen Montana brook trout chow the Thunderdome one cast after the other.

Thunderdome 3.I’m still figuring out color schemes for this fly, but this I know: It’s a done deal in overall color schemes of purple, gold, black and green. I’m still early in the testing process with the colors pink and brown, but they are showing promise.

As with another of my favorite attractor flies, my Gabriel’s Trumpet nymph, I tend to use a red wire rib when tying the Thunderdome. However, on the black and purple I use a silver rib, and it stands out brilliantly. On the brown version I prefer gold or amber simply for aesthetics. In each case the rib looks good, provides an appealing segmentation and toughens the abdomen. The downwing can be tan, light gray or white—all work—but it must be wool. Poly yarn and Antron yarn don’t provide wool’s buoyancy. Hackle colors normally match abdomen colors—green abdomen with green hackle, black abdomen with black hackle, etc. The thorax always matches abdomen color. The looped tail-shuck is always pearl Flashabou (unless you substitute an Angel Hair tail).

Thunderdome 4.The fuzzy dome on this fly can be whatever color best catches your eye. I generally go with yellow or chartreuse, but some prefer orange, pink, red or white. If you make the dome out of egg yarn, that ultra-fluffy synthetic used for tying little puffball fish-egg patterns, you’ll get a neat half-sphere effect. If you use wool you may not get a top quite so neat, but it’ll do the job. Either material floats all day if treated with a little fly flotant. Here again, don’t bother with poly yarn or Antron yarn—they won’t spread into a proper dome and they’re not half as buoyant as wool or egg yarn.

Thunderdome 5.Fishing the Thunderdome is simple: Just let it glide alongside banks or down the middle of a run, or let it sweep in on that swirl of current behind a boulder—but let it do so dead-drift, as though no tippet were attached. You can give the Thunderdome twitches, but I haven’t tried much of that, other than my aforementioned minor tenkara experiments.