Norman Winter Weather, 29-30 Nov 6

December 17, 2006 by · Comments Off on Norman Winter Weather, 29-30 Nov 6
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The recent winter weather event here in Norman left a nice layer cake of freezing rain ice, sleet and snow lying around for several days, with a much-needed 1.31 inches total liquid equivalent for the two day event. In fact, when I got back from a week-long trip to Miami nearly 10 days later, some ice still clung to a shady spot in the NE side of my roof.

I didn’t do much photography, though. Somehow a combination of unfavorable shift scheduling (day shifts, had to be inside during daylight hours) and lack of motivation to freeze my butt off kept me from doing much photography. Maybe next time, given a day off or two. ‘Til then, I did snap a wide angle shot of the National Weather Center building in the freshly layered and contoured snow.

This is one among many photos — some rather abstract or offbeat — that I’ve taken in and around the NWC building since it opened that I plan to post in an online gallery over the next few weeks. One of the offbeat ones had to do with the winter weather event also…

This image doesn’t seem to show much at first, but tells quite a pitiful story upon close scrutiny.

Note the dirt trail from right to left across the curving sidewalk. Also note the decapitated light canister at lower left, and the deep, snow-filled divot in the ground between that canister and the left edge of the dirt trail. Another light fixture is missing farther rearward as well; its canister can be seen lying sideways, partly buried in snow, at the base of the wall and beneath the wall-mounted light fixture.

Obviously someone (not me!) slid off the circular driveway, across the sidewalk and into the brand new landscaping, taking out two light canisters in the process. As far as I know this was the first vehicle crash to christen the new facility.

Malnourished Storms but Great Light Shows

September 17, 2006 by · 1 Comment
Filed under: Summary 

16 SEP 2006, SW KS


Skinny rotating Cbs intercepted in SW KS made for splendid sunset scenes. Convectively illuminating lightning show near HUT after dinner.


Elke, Donna and I headed NW through Woodward toward the FCST target area of “…SE-E of DDC, via NW Passage of OK” as posted on a discussion board. Some very helpful real-time information from Vince Miller (thanks a bunch for the calls, Vince!) confirmed we were on the right track, the question being what the atmosphere would yield in the most probable convective area. We measured sfc temps around Woodward around 93F, so given the dew points 66-68 F in the area, early storms would be rather high based with potential for lowering LCL with sunset’s onset. My main concern was how soon storms would form, if at all, before sunset. Vince was more optimistic, and as it turns out his suspicions were well founded.

Shortly after leaving Ft. Supply and taking the Buffalo split northward, we noticed an area of agitated Cu and Tcu to the NNW, NNW of Buffalo OK, along the KS border. As we approached the state line, a small Cb erupted from the clump, which would evolve into the initial SVR-warned Edwards County storm. So far this was working out far too well — initiation right on the SW rim of the forecast target area, a tad earlier than expected but manageable strategically. What would go wrong (besides the Stevie Wonder style Pac-10 replay officiating in Eugene OR)?

The Edwards County storm’s base was visible to the NW and N, off and on, weak rotation visibly evident as it took the hypotenuse track between Sitka, Greensburg and Stafford. Meanwhile we navigated the bases and sides of the triangles, never catching up with the storm but somewhat encouraged by other development to its SW (and to our W-NW).

All convection vacillated between hard and soft towers — but mainly soft, and sometimes even see-through. Given the warm midlevel temps, this wasn’t too much of a shock. I was hoping some of the towers SW of the Edwards storm would get deeper, and they did. Too bad they wren’t wider too. The main failure mode this day was updrafts that were too skinny. Here’s a young multicell clump with crepusculars to our W near Greensburg, S of the main convective area.

Malnourished updrafts squashed our hopes for a truly robust daytime supercell or tornadoes, but we enjoyed a wonderful sunset sky from 1 E Stafford which made the whole trip worthwhile. The narrow convective pillars and their collective anvils formed a fluid, multicolored rampart, catching so many angles and hues of the waning rays. Ghostly vaporous permutations of light and shadow (vertical, horizontal) projected across a skyscape that evolved wondrously minute by minute. Zooming in with eyes, mind and lens revealed otherwordly patterns of nature more in common with Hubble telescope images of far-away nebulae than with the humble prairie earth beneath.

After that glorious little show, we header E into Hutchinson for dinner, somewhat surprised by the lack of lightning in what was left of the sunset activity. I was hoping some of the storms could latch onto the low level jet and go berserk, turning into electically sizzling nocturnal supercells. An hour later, as we were leaving, numerous flashes caught our attention to the N, so we headed NE toward Inman to get away from the Hutch city glow and attempt some lightning photography.

That storm died as it approached SLN, but another one — a soft, but discrete and weakly rotating supercell — came up from the SW. As seen from 2 SW Inman, It put on a nice show of lightning illuminated convective structure (e.g., 1 looking NW,2 and 3 also looking NNW) before anvil precip from more upstream storms forced us to shut things down and head for home. [In case you’re curious about the feature beneath lightning shot #2, I thought it was a precip shaft. Here’s a deeply contrast-enhanced crop-n-zoom.] We rolled into Norman after 3 a.m., sleepy but fairly satisfied with a rare September storm intercept in the south-central Plains.

===== Roger =====

Textbook Backshear NW of Norman

August 26, 2006 by · Comments Off on Textbook Backshear NW of Norman
Filed under: Summary 

About two hours ago (as I type this), from Norman, I photographed a young multicell/supercell hybrid in Kingfisher County, about 60 miles away.

2105Z, Looking NW

Despite the distance, the cloud base was somewhat visible. Because of the hot inflow air and large dew point depressions, the LCL was high. It helped also that the boundary layer wasn’t too hazy. The best part was the development of a classical backshear on the west side, and a large “knuckle” (upside-down, moist convective cloud element) immediately adjacent to where the new updraft plume was roaring up into the anvil.

2108Z, Looking NW

Although I’ve seen this kind of structure numerous times in much more robust and sustained supercells, seldom have I photographed it. There’s no good reason for that, so why not start now, with a marginal storm but (nonetheless) an excellent visual specimen?

Ambient deep-layer shear was marginal today with only 20-25 kt of 500 mb flow and variable SE-SSW surface winds, but this storm had help down low. It formed at the intersection of an outflow boundary and a prefrontal surface trough shown on the graphic for this mesoscale discussion (available for the rest of 2006), and was a later version of the same “VIGOROUS YOUNG CB” mentioned in the text. [I just waited ’til right after getting off duty to run up to the roof and snap a few shots.]

We won’t be seeing cumulonimbi from the old NSSL building for very long. It’s possible these will be the last cloud photos anyone ever takes from there, in along and storied history of such dating back to a tornado over what is now far NW Norman in the early 70s. In less than a month the SPC operational forecast unit will move to the new National Weather Center. To get to the roof will require a lot more time and effort than just running two stories up one bank of stairs, but the view will be even more remarkable.

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