With a weak short-wave trough and residual monsoon moisture moving across Arizona there were possibilities that this would be a “monsoon transition” event. The vertical wind shear was in place but instability was marginal. The end result was a general lack of supercells—but that didn’t mean that the convection wasn’t interesting.
Multiple waves of thunderstorms moved across Grand Canyon with the earliest storms appearing before noon. With each wave, there was rain with some lightning followed by clearing and even some rainbows.
The first rainbow occurred while the sun was high overhead resulting in the rainbow appearing almost directly below in the canyon. This rainbow did not have brilliant colors but being able to see a rainbow over the Unkar Delta was interesting.
More showers…more rainbows. That was how the afternoon played out.
Late in the day I relocated to Yavapai Point for sunset colors and hoped for another rainbow. A partial rainbow appeared over the South Rim—but the arch did not continue up and over across the canyon.
The data and models suggested there would be convection from the San Francisco Peaks northward to Grand Canyon and into far northwestern Arizona. At best, however, these would be weak storms and would probably dissipate by late afternoon. With that in mind, I headed to the south rim of Grand Canyon. And the models were right about both the location and weak character of the storms. After shooting for a short time I left well before sunset.
As I was leaving, radar data showed a strong storm well to the southeast of Flagstaff. Leaving Grand Canyon National Park, I was able to see the storm in the distance and hoped I might get a few good photos at sunset. I stopped at Wupatki National Monument to take a few photos just as the sun was dropping behind the hills to the west. A moment later, I saw a flash of lightning. Then another…and another. These flashes were almost 40 miles away but were clearly visible.
I spent the next 90 minutes shooting lightning photos from this spot. The storm was moving towards me and the lightning bolts were getting closer, larger and brighter. There were lots of cloud-to-ground strokes with multiple branches and leaders lighting up the sky. Because these lightning bolts were south of the San Francisco Peaks and the Cinder Hills, there are no photos showing the bolts in contact with the ground.
Above is a plot of 24-hour lightning ending the morning of 10 September 2021. There are two distinct clusters of lightning around the San Francisco Peaks. The cluster to the northwest occurred during the afternoon. Many of these were visible from the South Rim of Grand Canyon. The cluster to the southeast of the San Francisco Peaks occurred during twilight.
And what of the time spent at Grand Canyon? Yeah, this is what I saw.
A few days of tropical moisture—remnants of Tropical Depression Nora—brought widespread rainfall to much of northern Arizona. As the moisture was replaced by drier air in the middle- and upper-levels but was unchanged in the near-surface layer, we were left with a situation in which fog might form in the early morning hours.
So, up before dawn to drive out to Mormon Lake and the surrounding basin. And there was fog—at least in one corner of the basin. Here is a 30-minute time lapse compressed down to 17 seconds showing the movement of the fog as it sloshes back and forth.
As this was taking place, the sun rose through a shallow layer of fog.
Bonus: on the previous evening the sun was setting through layers of smoke from the western wildfires.
The late February full Moon presented an opportunity to photograph the Moon rising between the dramatic Wotans Throne and Vishnu Temple in Grand Canyon.
Moonrise was about a half-hour before sunset. This meant that the distant walls of the canyon would still be illuminated by late afternoon Sun. On the other hand, the eastern horizon was still pretty bright as the Moon rose from behind Wotans Throne. So bright, in fact, that it was difficult to see the Moon. As a result, I got better results about 15 minutes later as the Sun moved lower and the Moon moved higher in the sky.
The second shot was taken just a minute or two before sunset and only the uppermost portions of the canyon rim remain illuminated by the sun. In addition, Earth’s shadow can be seen just above the horizon.
Bonus shot: While waiting for the Moon to rise I took photographs of hikers ascending the South Kaibab Trail just below and above Ooh-Aah Point.
This is the second year in a row in which the North American Monsoon has failed to deliver its normal weather to Arizona. The monsoon had a late start in July with only a few isolated rain events early in the month and the main event starting around the third week of July. But even that faltered after a week and the final week of July was dry.
August was even worse with no measurable precipitation until after mid-month and even then the amounts were light. The National Weather Service in Flagstaff has posted some climate data for the area for August. It was the hottest August and the 2nd driest on record in Flagstaff and most of the west experienced similar conditions (Figure 1; Figure 2;Figure 3).
Photographing summer monsoon storms has been a challenge this year because there were so many dry periods. Even so, there are always interesting weather events and clouds that make it worthwhile. So here is a collection of the most interesting weather photographs from this summer.
A time-lapse movie shows that the ducks are more interesting than the convection.
Full rainbows eluded me this year butI did manage to photograph a rainbow segment.
As with rainbows, lightning was elusive this year. It was typically a case of being in the wrong place on the wrong day and at the wrong time. But I did get lucky with the following image.
And when there is no lightning and no rainbow, one can be content with the sunset.