14 May 2010

Clouds spilling across the top of the peaks of the Sandia Range. Booth side jukebox controls in the Owl Cafe, Albuquerque, New Mexico. Circumhorizon arc. Note that the arc is nearly horizontal compared to the more common circular halo.

I departed Flagstaff around 10:30 a.m. to begin my drive to Norman, Oklahoma, where I will be participating in the National Severe Storms Laboratory (NSSL) 2010 Experimental Warning Program (EWP). Before getting on the highway, however, I noticed both a 22-degree halo and a circumhorizontal arc (or, perhaps it's the less common infralateral arc ) and I had to have a photograph. So I drove down the road until I could stop the car and shoot a few photographs. The arcs were already fading but with a bit of work I might be able to salvage the images. As I arrived in Albuquerque I was buffeted by strong easterly winds. Cool air had pooled east of the Sandia Mountains over the High Plains of New Mexico and was spilling over the top and was responsible for the winds. Clouds were billowing up against the east side of the mountains and draped across the top and then down the west side. This is a fairly common weather pattern in Albuquerque but it is the first time that I have experienced it. Most interesting. I had dinner at the Owl Cafe, a retro diner with counter service, jukeboxes, and more. It looks like something right out of the late '50s or early '60s that a traveler might have found on Route 66.

15 May 2010

NSSL N0XP Mobile Doppler Radar located south of Artesia, New Mexico. A dissipating thunderstorm over southeastern New Mexico. This is the storm targeted by VORTEX2 teams. It produced nickel- to quarter-sized hail earlier. A view of the crescent moon and Venus at twilight as seen from downtown Artesia, New Mexico.

I left Albuquerque with the goal of heading to southeast New Mexico in hopes of finding photogenic storms. My first stop was in Roswell so that I could look at new data. Since no interesting convection was occurring yet, I had time to visit the Roswell Museum. Although the museum is interesting, it's certainly not compelling enough to drive here just for a visit. Unless, of course, you are truly into aliens, conspiracy theories, and more! After a quick lunch stop it was back on the road again heading south where I encountered the VORTEX2 armada between Artiesia and Carlsbad. There still wasn't much happening convectively so I went into Carlsbad to reserve a motel room and check data again. Finally a storm initiated over the mountains and was beginning to organize and move eastward. I went back north to Artesia where I encountered nickel- to quarter-sized hail falling from the back of the anvil. The storm was already weakening and I let it go eastward across the high plains and ranchlands. As twilight deepened, there was a great celestial show in the west as the crescent Moon was very near the planet Venus and both were shining brilliantly in the clear evening sky.

16 May 2010

Hartweg's Sundrops with morning mist on its petals. Streamway and riparian zone at Silver Falls Rest Area in Texas.

Today is a travel day as I must get to Norman, Oklahoma, this evening. The Storm Prediction Center (SPC) has included a Slight Risk across portions of Oklahoma this afternoon for a 15% probability of large hail. I keep my eyes open but all I see is low stratus and drizzle across much of the western Texas Panhandle and small cumulus over the eastern Panhandle and southwest Oklahoma. The Slight Risk, in fact, verified. Large, damaging hail occurred from a severe thunderstorm that moved east-southeast across portions of metro Oklahoma City and produced hail up to 4 inches in diameter. I'm glad I didn't encounter any of that. Later, additional storms formed that produced large hail across the track I had taken earlier in the day across southwest Oklahoma. Along the way, I stopped at a pleasant rest area east of Crosbyton, Texas, called Silver Falls Rest Area. It has been newly reconstructed but is based on a much older site that was probably built in the 1930s by the CCC. There is a small stream and a series of water cascades in the area. The abundance of water has allowed trees to flourish providing ample shade for travelers. One more thing: I took I-44 northeastward across Oklahoma and then took the Norman connector only to find the toll booths unattended and I had no change! What to do? Since there was no traffic at that moment, I quickly backed up until I could safely park on the side of the highway. I then spent a few minutes searching all the little nooks and crannies that cars have until I came up with the correct change, dropped it in the money bucket, and proceeded on my way.

17-21 May 2010
National Weather Center, Norman, Oklahoma. The Development Lab at the National Severe Storms Laboratory. Each day's briefing and discussion starts here. The Hazardous Weather Testbed work area at the National Severe Storms Laboratory. Each days forecasting and warning experiments take place here.	I'm in Norman, Oklahoma, for the 2010 EWP. I will not be chasing this week. Instead, I will be forecasting severe weather scenarios using new technologies and software. This should be both exciting and challenging and I'm looking forward to the experience. If you're interested in additional information, the National Severe Storms Laboratory has a web page for the Experimental Warning Program.

22 May 2010

Monument Rocks, Kansas. Monument Rocks, Kansas.

I left Norman, Oklahoma yesterday afternoon with hopes of intercepting some photogenic storms along the dry line in western Kansas. The forecast models (in particular, the HRRR and the WRF-4km) were suggesting the possibility of a supercell developing in this general area. A storm did develop but it dissipated quickly and there was nothing left by the time I arrived in the early evening. The target for severe thunderstorms today is in South Dakota and may move into North Dakota by late afternoon and early evening. I'm too far way to get there in time so I've decided to do some sightseeing in western Kansas. I visited the Monument Rocks area located southeast of Oakley, Kansas. The rocks are a series of large chalk formations and it is a National Natural Landmark. In addition, it has been named one of the Eight Wonders of Kansas. As interesting as they are in their own right, it would have been wonderful to photograph these beautiful rocks with some large thunderstorms as a background. Another time, perhaps.

23 May 2010

Carousel at Kit Carson County Fairgrounds in Burlington, Colorado. Supercell developing northwest of Tribune, Kansas. Lightning at twilight in a supercell northeast of Goodland, Kansas.

During the night a cold front pushed southward across northwest Kansas leaving the area in a cool, dry northerly flow. That should change this afternoon as a surface low is forecast to develop in eastern Colorado. The isallobaric pressure field should cause the winds to become easterly or southeasterly during the day with moisture returning northward. I drove west from Colby, Kansas to Burlington, Colorado to meet Matt and Betsy who are driving eastward from Denver. Our designated meeting place was the Kit Carson County Fairgrounds where an old carousel is housed. Unfortunately, the carousel was still closed for the season and will not open for another week so I had to be content to photograph it through a window. From Burlington we traveled south to Sheridan Lakes, Colorado then east to Tribune, Kansas where we watched convection develop to our south on the leading edge of the returning moisture. We moved northward to Sharon Springs, Kansas then dropped back south to intercept the western storm and followed it back to Sharon Springs. Other storms were developing to our east and we went east as well but eventually decided that our original target was still the better choice. So we went back west to Sharon Springs and then north. By this time, the storm was becoming a very organized supercell and we began to look for opportunities for photography and to carefully watch for tornadoes. Shortly before 8 p.m. MDT, we saw a brief tornado to our northwest while were about 5 miles south of Goodland. Me? I was fumbling around with my camera tripod and missed the brief touchdown. It was rapidly getting dark and we drove to Goodland and then eastward onto I-70 where we briefly saw another tornado as it was illuminated by lighting flashes. A few miles farther east we stopped for some lightning photography. Then it was back on the road to Colby, Kansas and dinner at the Village Inn. At the VI we ran into many of the VORTEX2 crew which explains why most of the motel rooms in town were already booked. Luckily, we had made reservations earlier in the day at a small "Mom and Pop" type establishment. Inexpensive, clean, and comfortable. Who needs more than that?

24 May 2010

Rapidly moving supercell thunderstorms pass by an abandoned farmhouse near McCook, Nebraska. A tornado warned storm moves over the town of Oberlin, Kansas. Sunset colors on a distant storm. Sunset colors on a remnant anvil.

A very strong, negative tilt trough was forecast to move across the western high plains resulting in a deepening low pressure system in Colorado that would quickly move north into the Dakotas by evening. The winds aloft were generally all southerly so this made for fairly straight hodographs everywhere except just to the northeast of the low. We decided that the drive from Colby, Kansas to western South Dakota was more that we were willing to commit so we targeted storms that formed in western Kansas and western Nebraska. (In retrospect, we should have made the effort. The photographs of the storms in SD were amazing!) We drove from Colby northwestward nearly to Ogallala, Nebraska before recognizing that these storms were moving too fast and were not good targets. We returned the way we came then turned east towards McCook, Nebraska. Eventually, we realized that the only targetable storms left were located on the dry line which was finally beginning to advance eastward late in the afternoon. With the strong meridional flow and with storms lined up south to north on the dry line, each storm was raining into the storm to its north disrupting the organization. Eventually, we intercepted a storm near Oberlin, Kansas which was briefly tornado warned. Even this one, though, was disrupted by its southern neighbor and never really threatened to produce a tornado. We turned back to Colby (again!) for dinner and motel rooms and were eventually rewarded with beautiful sunset colors on the clouds as they continued to move to the east.

25 May 2010

Supercell near Towner, Colorado with ground-hugging inflow. It was rotating -- slowly -- but was it a tornado? Pre-tornadic storm with a clear slot and strengthening rear flank downdraft. Brief tornado north of Tribune, Kansas. VORTEX2 was all over this storm. Anvil cloud with mammatus at sunset.

We left Colby, Kansas and went west to Burlington then south to Holly, Colorado where we analysed new data and reassessed. On the drive south from Burlington to Holly, we had crossed the stalled frontal boundary where tempersatures were ~60F on the cool side and ~80F on the warm side. Storms that crossed this boundary later in the afternoon would likely experience some local increase in storm relative helicity (SRH) and have an increased probability of becoming tornadic. We left Holly and went east to Syracuse, Kansas and then north to watch a distant supercell thunderstorm to our southwest. Unfortunately, we delayed a little too long and were late getting to the landspout fest west of Towner, Colorado. At least we managed to see a few of them from the highway as we approached. After arriving near Towner, we watched the storm form an impressive inflow on its north or northwest flank with rapidly rising scud tags. At the same time, a cold outflow boundary from the north pushed south towards the storm. Thinking that the storm was undercut by the cold outflow we turned away and drove east back to Tribune and then started south to intercept the next storm. When we heard the new tornado warning, we turned back north and eventually intercepted the storm as it crossed the highway north of Tribune. We saw two tornadoes: a less than 1 minute truncated cone tornado followed by a 2-3 minute rope/elephant trunk. (Tornado classification scheme.) We decided to target a new storm to the distant southwest but this storm moved across rain-cooled air from the earlier storms and never became severe. Leaving the storm we were able to see some great mammatus from the storms farther south in Baca County.

26 May 2010

Supercell south of Keenesburg, Colorado (1622 MDT). Supercell north of Fort Morgan, Colorado (1902 MDT). Supercell north of Brush, Colorado (1922 MDT). Supercell north of Brush, Colorado (2005 MDT).

Morning analysis indicated a chance for supercells from southeast Wyoming across eastern Colorado. As an initial point, I selected Kimball, Nebraska so that I could monitor storms developing along the Cheyenne Ridge as well as north and south. Before reaching Kimball I stopped on a hilltop and wasn't there long before a strong storm developed in the Denver area. After watching the radar for awhile and not seeing anything interesting locally, I drove south and west back towards Denver, turning south on SH52 at Wiggins and then following it as it turned west. I set up just across the Weld County line with time lapse video and photos. This location was a fair distance east of the storm but it afforded me a great view and there was no one else around. At least, not initially. As the storm slowly, slowly moved to the ENE, other chasers showed up as well as various VORTEX2 vehicles. I eventually left this location and moved back to the northeast: first on Long Bridge Road, then Dodd Bridge Road, and finally just west of SH71 north of Brush. This was one of the slowest moving supercells I've seen in quite some time. It never looked tornadic to me -- but I was often a fair distance east and may have missed some small spinups. The structure was great and improved during the day. I tried to get some lightning shots but there wasn't that much CG lightning and not even that much IC, either. A very photogenic day! Time lapse video (~35mb) of the early stages of the storm.

27 May 2010

Abandoned homestead near Orchard, Colorado. Peace Art Cafe in Del Norte, Colorado. A great place for lunch.

The strong winds aloft of the past few days have weakened and the chances of supercells has significantly diminished. Still, there is a Denver Convergence Vorticity Zone (DCVZ) today so I might as well check it out and hope that a storm forms in that area. It's still early in the day when I leave Fort Morgan so I do some sight seeing along SH144 which follows a portion of the South Platte River. There are a few abandoned homesteads here and I take advantage of the opportunity to photograph some. As for the DCVZ--well, nothing happened. The moisture was too shallow and when convective temperature was reached the moisture mixed out. Still, all was not lost. Even though deep moist convection was not going to happen, there was still plenty of surface vorticity along the boundary and I might get lucky and see some large whorls and dust devils. Alas, the DCVZ was not even able to do that. The following day I drove southwestward across Colorado and arrived home in Flagstaff late in the evening. Along the way, I stopped at a charming lunch and art shop in Del Norte, Colorado. It's worth a visit.