2008 APRIL 17: WILLOW PARK, TEXAS TORNADO
 


Tornado ~4m NNE of Willow Park, Texas @ 0022z, observed from ~3 miles west

  I observed the northernmost supercell first, taking a position near Chico, Texas, but I was blocked from further approach by Lake Bridgeport. The storm showed disorganized lowerings but became outflow dominant. When rain from the southern storm contaminated the updraft region, I dropped south toward Weatherford. I noticed that even as my old storm became more linear, it continued to show strong low level rotation in the "notch" features that developed along the forward flank. The southern cell showed a similar pattern.

Near Azle, I turned on FM 730 with a southwesterly tack to skirt the core. While I was flanking, Parker County spotters reported tennis balls and baseballs on the north side of Weatherford, with a lone softball report as well. This was an important development as the hail effectively pinned the spotters along and south of the interstate. I turned briefly east and then south on FM 3325 to approximately seven miles east of Lake Weatherford. Another lake. The updraft was to my west and growing obscured as the old long-lived hook folded into more of a notch. Though I haven't checked archived data, I believe the storm retained supercellular characteristics at this time, around 7:15 PM.

Just north of the FM 3325/White Settlement Road intersection, a large wallcloud came into view, about four miles to my west. This feature was connected to the base of the storm. In the photo above, a forward flank cloud deck in the immediate upper foreground hides the real base. That cloud deck is not the distant storm's base. Nor is the blocky condensation from which the tornado extends the updraft base; that's the wallcloud. This configuration was more apparent in later views from White Settlement itself, when the storm was closer and base and wallcloud both became visible. At the time, it was confusing. I stopped on the crest of a private driveway as cascading "sheets" of condensation moved from north to south into the wallcloud. The primary "core" of the wallcloud, on the left side, assumed a cylindrical shape and began to rotate.


immediately prior to tornado formation

An RFD cut appeared on the southern edge and a funnel extended rapidly. I wasn't confident about what I was seeing, but thought I should keep shooting stills and sort it out later. As I mentioned, I put the time of this around 7:22 PM, and it lasted no more than ten seconds. I've guessed it was approximately four miles NNEof Willow Park, Texas or eight miles ENE of Weatherford.


note in map should read "at right"

When I logged a funnel report on spotternetwork, my position and therefore my report appeared about twenty miles west of the actual observation, due to a problem with my GPS data stream. Moments later, a Parker County spotter logged a full tornado report on SN in the correct position. Presumably this spotter had a view of the base of the funnel and confirmed that it reached the ground. Either this spotter or another contacted NWS by phone; the ham operator at FTW mentioned the report on the Parker County net minutes later. Most of the spotters were still trapped in Weatherford or down on the highway, having taken cover from the destructive hail. I didn't realize this until later and after talking with other people today. If I could do it over, I would have called FTW first and worried about SN later, but with the confirmed report (and a tornado warning already in effect), I concentrated on fleeing the mongo hail.

The line followed me into the Metroplex. I turned around occasionally to see if the notches would spin up something else. On White Settlement Road I was able to track the still-prominent wallcloud, then followed 820 north along the western side of Fort Worth to the northwest quadrant. I saw a few lowerings, nothing impressive. But traffic made this an increasingly dangerous effort. I dropped south onto I-30 with the notion of posting myself immediately east of downtown Dallas for some skyline lightning photos. Well, I'd never tried this before, and found it a frustrating effort. Beyond elevated roadways, I couldn't find a single prominent vista. I'm sure there's many; I just don't know where they are. I don't make a habit of chasing downtown so I've never had cause to look.

The squall line swallowed me as I flailed around Deep Ellum looking for a view. Then I drove home in the rain.

Structurally, this convection was well beneath 2008's standard. The best part of the chase was that it started late, so I'd already put in a day's work, and it ended back home without incident. If I ever complained before about the lack of chasing in northwest Texas or southwest Oklahoma, I take it back. I'm ready for the caprock or the front range or any high plains vantage point. Maybe next week.