June 2006

Ever since first reading about it, and even more so seeing what High Dynamic Range photography (HDR) techniques could do, I have been intrigued by the possibilities. In a nutshell, the HDR imaging technique involves utilizing software that digitally combines multiple photographs of the same subject taken at different exposures - either different shutter speeds, different f-stops, or some combination thereof. Following the layering of these images, a follow-up process known as tone mapping is required to flesh out the details. The result is not a simple overlay of multiple images, but rather a best-of-each-image blending of the detail. The blown-out highlights of an overexposed image are subdued and the underexposed shadows of the other end of the bracket are brought out. After viewing a few samples posted on various message boards, I began reading more about the technique as well as checking out numerous spectacular samples here, here, and some great and not so great (overdone) samples here. I started by downloading the trial version of Photomatix.

Earlier in the month I had the opportunity to make a few test runs at this and found it to be surprisingly simple. While spending the day in Kansas City, I made a point of shooting several brackets of photos inside and outside of Union Station. The image above is a combination of five photographs. Three of the five images are shown below and as you can see, the HDR image jumps even more than the best exposure below (click image for larger view):

I also attempted the same at a Royals/Rangers game later that evening at Kauffman Stadium. This time, I took a few more liberties with the virtually infinite adjustments available in the tone mapping part of the application to really make the image ‘pop’, although it admittedly takes on a more artistic bent rather than a purely documentary angle.

Notice there are more than 9 Rangers on the field…this is because the images were not auto-bracketed on the camera; it took me a fraction of a second to make the manual adjustments between each frame and in that time, some players moved slightly, like the first baseman, the runner on 2nd, and the third base coach.

I’ve never been into much “photoshopping” of images…the only edits I’ve made in the past have been to crop and resize and of course I recognize that photography is not purely a science and that even making manual adjustments on the camera constitutes a certain level of “editting” to some, but when it comes to exploring the artistic angles now possible, some of these HDR techniques certainly pique my interest.

Former president Clinton stated Monday that GOP environmental policies will lead to more global warming and thus more hurricanes.

As Tropical Storm Alberto threatened to strengthen into the ninth hurricane in 22 months to affect Florida, former resident Clinton predicted Monday that Republican environmental policies will lead to more severe storms.

“It is now generally recognized that while Al Gore and I were ridiculed, we were right about global warming,” Clinton said at a fundraiser for the Florida Democratic Party. “It’s a serious problem. It’s going to lead to more hurricanes.”

Gore’s documentary, “An Inconvenient Truth,” chronicles the former vice president’s efforts to educate the public about global warming. It’s in limited release around the country.

I’m not much of a hurricane hunter…they don’t do all that much for me. But severe weather over land does. If GOP policies can make more hurricanes, perhaps the GOP can do something about this rather quiet severe weather season that the Midwest/Plains has experienced. If you weren’t out in April chasing the storms that blew by at Mach-2 then you haven’t had much of a chance to experience good storms as May (and June to date) was relatively quiet.

At this point, I think we all need to get on the horn making phone calls to our local representatives and let them know that they need to take a stand against this death ridge if they expect our vote in the fall. Vote for more storms: Vote GOP!

Lightning east of Miller, Nebraska on 06/05/06

With a moderate risk posted by the 13z SPC outlook, we were cautiously optimistic about the day’s chances although admittedly guarded about tornado chances. We knew all the ingredients weren’t quite there for tornadogenesis, but we still had hopes of viewing some nice structure and getting some good lightning shots. We started the day with a general target of Hastings, NE. A 500mb speed max from the NW was progged to drop down off the ridge as the low level jet kicked in from the south and surface moisture returned behind the morning MCS. The back side of that morning MCS was quickly eroding and hopes were that daytime heating, along with some boundaries dropped by the MCS would be enough for a trigger.

We headed out around 11am and made the 200 mile trip to Lincoln where stopped for a quick lunch and data. By this time the SPC had slightly revised their moderate risk and the morning MCS that had been in place over SE NE was quickly sliding farther SE, allowing for some clearing to the west of Lincoln. A pre-frontal trough - hanging out about 100 miles ahead of the SW- to NE-oriented cold front that was just now entering NW Nebraska - was now sagging south and around the Broken Bow area. This trough was now the main focus by the RUC and the SPC as the source of ignition for the day’s storms. BBW was a bit out of our driving range by this time but we decided to make it as far NW as we could.

By late in the afternoon we were NW of Grand Island, heading NW on highway 2. Two cells had blossomed - one to our west, another to our north. We were now getting tucked beneath the anvil of the storm to our west.

After leaving the interstate, we no longer had a data connection so were going only by sight. The atmosphere was a bit soupy and while the updraft towers had some nice, crisp edges to them, the updraft bases were annoyingly undefined. A nice display of virga was ongoing to our SW as we continued NW.

We continued NW to Ansley which we felt was a good place to pause, giving us a nice N-S road option should the cell to our NW continue to make progress to the SE. By this time, the cell in Custer County was SVR-warned and the weather radio - our only source of data - was indicating storm motion to the East at 15 mph. These storms were indeed crawling, although slightly more to the SE than East. We stayed ahead of the Custer County cell the entire time, dropping south on US 183 just ahead of it. We never got behind this cell, realizing only after the fact that the SE movement probably meant that being more to the S or even SW (rather than E or SE) would probably have afforded us a better view. We dropped down to Miller where we stopped to get some lightning shots as the cell was now putting out CGs at the rate of one every couple of seconds. Click images for larger view (this should work for all images in this post). Most images were no more than 2 second exposures with the Canon 30D kit lens (18-55mm) stopped down to F/22. Adjustments made in photoshop were limited to cropping, resizing, levels adjustments, and USM. As always, just click on the image for a larger view.

As this cell approached us we began getting light rain at our location so we packed up the gear and meandered our way down to the interstate. While shooting the lightning, the others were able to grab new data. The data didn’t look promising: there were no discreet, good-looking cells on radar, rather a smattering of marginally severe cells spread throughout several counties in central and western Nebraska. It was now close to 7pm so we decided to start making our way back East along I-80. As we did so, the setting sun began to illuminate the cells that were weakening to our west. We pulled off around exit 353 (York, NE) to sit atop the overpass and get a few shots of the orange glow. The only adjustments made to these images was resizing in photoshop.

Storms: 2 SVR-warned cells
Total miles: 750

2hr RUC Surface-based CAPE valid 20Z 06-June-06

After a disappointing day in south central NE yesterday including 14+ hours on the road, we’re staying put today in KTGX and hoping the cold front fires not far from home.

The cap is quickly eroding, great instability parameters, low LCLs (much more impressive than yesterday’s in NE) and the front is finally on the move. Shear is on the low end so the tornado threat is minimal, but some good structure could be in play. Initiation should come anytime this mid-afternoon, although some cloudcover east of the KC metro may inhibit heating in the regions of the best instability and moisture convergence around KC when the front comes through.

Day 1 (and likely the only day) of our chase vacation is underway with a preliminary target of Hastings, NE as a starting point with revision to the S as needed…given our morning placement, we’d rather be on the southern end of this show, hoping to catch the end of the line rather than racing to the northern edge of the best instability (Norfolk, NE and northward?) as that would be a race against time.

Ongoing overnight convection (MCS) has slopped up the surface data and impeded the models from having a good grasp of the best instability placement for later this afternoon. However, we’re encouraged by the outflow that should be set up on the western edge of this MCS and be available to interact with the cold front as it pushes SW this afternoon/evening. Caveats include the exact placement of this afternoon’s boundaries as well as how quick the clearing comes about. I’m encouraged by the decent decay rate and SW movement of the current convection as giving us a good afternoon window for some heating to encourage surface-based cell growth.

With a cap eroding in the mid-afternoon, the mid-level jet coming into play at ~50kts, a nice low-level jet nosing in through eastern KS, initiation should occur in the 3-5pm timeframe. However, in the last couple of hours, VIS SAT trends do indicate some blossoming convection on the SW edge of the MCS in Western NE and KS which is not what I’d like to see at this point in thte game…clearing and a cap is what we need this morning.

Depending on how far north we travel, the mean storm motion of ~SW should allow us to ride the convection home and if nothing else, provide a nice opportunity to experiment with some lightning photography this evening.

As this looks like our only real SVR shot during our chase vacation window (6/4-6/7), we’re optimistic about the day.