Oklahoma City HP Ice Machine

May 16, 2010 by · Comments Off on Oklahoma City HP Ice Machine
Filed under: Summary 

Oklahoma City to Ada, OK (16 May 10)

SHORT: Observed fast-moving HP supercell from eastern Oklahoma City to between Seminole and Ada, then let storm pass by into southeastern OK.

LONG:

In the couple of prior days, I had considered some potential for severe storms across the region — mainly between I-40 and I-20 where it appeared the strongest midlevel winds would occur in a belt south of a mid-upper level trough over the central plains. The problems seemed to be lack of coherent initiative foci, rather weak moisture (resulting from the air mass to our S over TX being scoured by huge convective complexes), and weak near-surface winds that would keep hodographs small.

With far more negatives than positives apparent, I (along with many other storm observers) didn’t pay a great deal of attention on the day of the event. In fact, I was eating late lunch in Moore with Elke, Rich Thompson, Jack Beven and Jim Leonard — all experienced chasers of many decades in aggregate — when a supercell materialized out of a clump of convection NW of us near Okarche. The hook echo on the TV display and on our phones definitely got our attention.

Yes, a quick look at the surface map showed weak, mainly SW winds at the surface, though there was a sharply defined, E-W boundary extending N-NW of OKC. Turn the entire setup (including NW-SE storm motion) leftward 30-45 degrees, and you’ve got an east-moving storm with light SE winds. That’s not bad. Surface dew points in the inflow region were on the low side at about 62 degrees F, but the presence of the storm told us that was more than sufficient! Bellies full, we all scattered to our respective domiciles to get camera gear, and ended up separately observing the supercell.

Elke and I headed N from eastern Norman intending to photograph the storm coming over downtown, but its gradually accelerating motion precluded that. Instead, we first got a good look at it to our NW near the junction of I-240 and Sunnylane, with lots of buildings, wires and such contaminating the foreground. It was moving SE at 35 mph and accelerating further, and we had to head E on I-240/40 to stay ahead, if we wanted any hope at a good view without getting demolished by the baseball to softball size hail that was pounding northern and eastern Oklahoma City. We also drove right past the intersection of Choctaw Road and I-40, where a violent tornado had destroyed a truck stop and caused casualties the previous Monday. No time to look…we had to keep going!

Along the way there, we were listening to the radio simulcast of KFOR-TV, where Mike Morgan was saying, “We’re under attack at the KFOR studios! Skylights are breaking, baseball hail falling right here! We are under attack! This storm is taking no prisoners.” Now, Mike is not exactly the dignified, stoic gentleman of 1960s/70s television, seriously delivering the dire news of impending meteorological doom. He is no Harold Taft by any measure, and never could be. That said, while his penchant for over-exuberance and occasional exaggeration is well-known, he wasn’t too far from the truth this time.

Meanwhile, eastward we forged in search of a vantage. In this part of central Oklahoma, the Eastern Crosstimbers arboreal province, it’s very difficult to get a good view of a storm, with the trees, hills, and buildings rampant. We pulled off I-40 several times in futility, but finally and briefly found a very nice look about 2 SSW of Dale, on OK-102. To our NW, the north part of the storm (where the mesocyclone was) sported a beautiful tail (stinger) cloud, with a cream/reddish wall cloud rotating weakly. It was obviously being undercut by outflow and in no danger of a tornado. Given all the tornadic destruction of six days before, this was a good thing; because folks in these parts are hypersensitive to big, mean-looking storms.

I managed to photograph the south part of the supercell (looking W) before the storm closed in. We zigzagged S and E to Seminole, edging the hail core (nothing damaging), and driving past more of the previous week’s tornado destruction along Highway 9. Not wanting to get munched by a hail core in Seminole, we charged S to 12 N of Ada, and let the outflow-dominant storm race across the road right behind us.

All in all, this was an unexpectedly rewarding afternoon for a couple of storm observers who hadn’t counted on seeing much. Unfortunately, Oklahoma City took an epic beating from the hailstorm, the costs of which will run into the tens (maybe hundreds) of millions, not counting the insurance premiums that are sure to skyrocket even more. Since we stayed (mostly) ahead of the storm, I don’t have any hail photos, but the brief episode of photogenic structure near Dale was well worth the effort.

HP Heaving on Hutchinson

July 9, 2009 by · Comments Off on HP Heaving on Hutchinson
Filed under: Summary, Uncategorized 

15 Jun 9
Central KS

SHORT: Observed skinny supercell from N between Scott-Ness Cities. Performed an end-around intercept on HP supercell-turned bow from E of Kinsley to HUT. Munched by bow/HP hybrid in HUT.

LONG:
Once again, we were faced with two interesting target areas — the “north play” near what turned out to be a warm frontogenesis zone along the KS/NE border, and the “south play”, along the prior day’s OFB over SW KS. I didn’t like the south play as much because of the forecast (later observed) smallness of hodographs and persistent SW flow right through the boundary for hours on end. Nonetheless, we headed that way from Oakley (despite being closer to the northern play) after three trends appeared:

1. Winds began to lighten N of the old boundary but not to its S (speed convergence) and

2. Midlevel (i.e., 500 mb) winds appeared stronger farther S, as proged, although low level shear and SRH were bigger in the warm frontogenesis zone, and

3. Storms erupted to our S.

I wanted to hold out longer for the N play, but convective bombs going off were too tempting when compared with the “pancakus” Cu around us and to the N. I’m not sure we would have gone all the way ENE to HSI for that amazing warm frontal storm, but we were in ideal position for the NW KS activity later.

A lone supercell formed N of GCK, here shown at wide angle from N of Scott City, then a separate, zoom view of the backside updrafts. In the background, another cluster of convection SW of GCK could be seen; those eventually would hog the inflow and choke off out storm. As we drove past its near N side, the updraft looked rather skinny, but was quite intense. Then too many other storms formed in too close a proximity to its SW-SE, and we had to make a choice — go back N toward the NEb border (no deep towers yet visible) or go a long way E then S to get ahead of the lead storm N of DDC. As we headed E past Ness, the lead storm started absorbing cells of assorted sizes to its E and “jumping” mesos eastward, forcing us to go still farther E before dropping S.

We finally did so through Larned, St John and Sylvia, encountering a few hailstones of unknown size in the far forward flank (heard ’em loudly, didn’t see ’em). Heading S toward St. John, I finally got a view of the business end off to the SW — a dark, menacing, HP supercell, absorbing yet another storm (itself with a high but circular/rotating base) into its forward flank. I might have seen the tornado near Macksville as a persistent, gray on darker gray, bulbous form back there in the mesocyclonic murk several minutes later (no photos…very low light, moving). It was about the right distance, direction and time.

We stopped briefly S of St. John to view the dark menace approaching, then headed E and NE toward HUT to stay ahead (wide-angle photo looking WNW from near Arlington KS). Finally deciding this wasn’t worth going any farther E, we found a protective place and let Stormzilla move over. A sporting goods store on the S edge of HUT was kind enough to let us park under their front porch overhang, right against their doors. It’s not often you get to just stand there well-covered in the lee side of a building, relax, run out now and then to shoot some photos of the oncoming HP/bow Stormzilla, and then let it blast you, no worries.

This was one case where having the I-Phone radar provided assurance we wouldn’t be in a truly dangerous part of it (using the DDC radar, since ICT’s 88d timely fried its antenna motor over an hour before). The apex of the bow passed just to our S, the bookend vortex ( old meso from HP phase) just to our NW and N ( here lit by some anthropogenic glow from the W side of HUT), and we sat in an intermediary channel of estimated tropical storm force (~40-50 kt) WNW winds for about 15 minutes. Power went out there and everywhere else we could see during the maelstrom.

After the wind-whipping, we headed back toward GBD for lodging. A couple miles S of Sterling KS, the solar orb appeared below the razor’s rear edge of the MCS anvil shield and above the top of the far-away deck representing storms in northwest KS. This started up a brief but dazzling double rainbow, its hues warmed across the entire palette thanks to the low sun angle. We stopped to appreciate and photograph it across a deeply golden wheat field foreground, with a strip of green corn in the distance. The wheat looked well-nigh ready for harvest.

Then came dinner in GBD, where we parked next to yet another among many “look at me” chase vehicles hereabouts in the Plains. This one was festooned with Skywarn stickers, assorted “Storm Chaser” decals, a “J2” decal (as if this was one unit of some sort of team…suuuuuure), and an assortment of anemometers, antennae and PVC tubing atop. Upon closer inspection, only one antenna had any wiring leading inside the vehicle; and the anemometers and tubing were wired up to absolutely nothing. Posers. The large stencils on both sides of the rear windows for a local janitorial service cinched the deal. Yep, we found none other than the Janitor Chasers — keeping you safe and clean!

We ended the evening watching and photographing mainly in-cloud lightning and occasional LTGCA filaments from a band of elevated storms that formed just south of town (and later moved N). It was a neat show, as seen from the open field behind the GBD Wal-Mart. [Mr. Jewell knows exactly where this is.]

Be advised, if you must travel through GBD anytime soon, the main E-W route is torn all to hell, and down to one abominably rough lane each way, for about 1/2 mile W of downtown. Keep your windows up too, for the long puddles in the adjoining swales of construction mud smell like the bowl of a bus station commode. But our lodging was good, and cheap (<$50 again), and that line of elevated cores provided a thunderous late-night lullaby.

Northern Burlington at Sunset

July 7, 2009 by · Comments Off on Northern Burlington at Sunset
Filed under: Summary 

14 Jun 9
Eastern CO

SHORT: Saw high-based, outflow dominant storms from the distance in central Colorado, evaded eastward, waited for other storms to form but not long enough. Treated to wonderfully colored sunset at Burlington CO.

LONG:
Elke and I had a good breakfast at the Memories restaurant in Ft. Morgan (highly recommended), before dropping S toward Last Chance to await storm formation possibilities either on the CYS or Palmer Ridges. While sitting on a hilltop between Last Chance and LIC, we saw a very distant Cb explosion to the NNW, which I-Phone radar revealed to be a rapidly evolving supercell near Chugwater. That was out of reach, realistically, and so was the potential afternoon target along the boundary in SW KS.

We waited longer for Front Range and/or Palmer Ridge storms, dropping S to LIC for shade and better data access. While there, a tornado-warned line of storms quickly fired over the DEN metro area (producing that funnel near downtown and Coors Field). I was disinclined to run immediately after that activity, given its linear and likely high-based character.

We kept waiting at LIC for closer development, which did happen to our W and SW. Alas, it was linear too! Still no photos for the day yet…the activity was distant, but I already could see a shelf cloud emerging through some mild haze WNW-SE of us. I envisioned an unfriendly wall of outflow surging E across central and eastern CO, so we threw in the towel on active chasing for the day, perhaps a little too soon.

We arrived at ITR, got a nice and cheap motel room, and ate dinner at the slow and overpriced steakhouse there (not recommended!). We clung to hope for at least an interesting, shelfy sunset. Meanwhile a couple of brief supercells appeared near the tail end of the line before being munched by the meso-beta scale cold pool (these were the storms observed by BillR, MattC and MikeU).

Even the linear MCS appeared to weaken as it headed toward us, but we went to the N side of town to watch it roll past anyway. The sky was remarkably hazy for eastern CO, but once the gust front hit, the view cleared a good deal. A line-echo wave pattern (LEWP), with a brief and embedded supercell to our N, sent a rear-flank augmentation overhead just in time for the setting sun to shine through its precip curtains, opening up a brief bu dazzling splash of warm coloration in the rain curtains.

As the reds began to fade, the blues deepened in the nooks and crannies of the overhead shelf cloud’s turbulent underbelly, compelling a wide angle shot of the beautiful and unusual scene. It was a fantastic way to close out what had been a rather uninspiring storm day.

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