Lightning and shelf clouds


The past few days have produced interesting storms across northern Arizona.

An isolated thunderstorm develops at sunset.
An isolated thunderstorm develops at sunset.
Lightning illuminates an updraft.
Lightning illuminates an updraft.

An isolated storm developed around sunset and produced both wonderful colors and lightning. Most of the lightning, however, was on the other side of the updraft so the storm instead was lit from the inside like a lightbulb. The storm colors and lightning was nicely reflected in the waters of the Kachina Wetlands.

Low clouds from thunderstorms envelop the San Francisco Peaks.
Low clouds from thunderstorms envelop the San Francisco Peaks.
Outflow boundary and low clouds arrive in Sedona.
Outflow boundary and low clouds arrive in Sedona.
Lightning over the Mogollon Rim.
Lightning over the Mogollon Rim.

A few days later a large line of convective storms moved southwestward across the state and produced a haboob in the lower (and drier) elevations. As the leading edge of the rain-cooled air moved across the San Francisco peaks the clouds quickly enveloped the mountains. About an hour later, the shelf cloud arrived in Sedona and new storms began to develop.

 

Thunderstorms and Lightning

The North American Monsoon has been sputtering—for lack of a better term—the past week or two. We get a few days of storms followed by a hot and dry period. Finally, however, moisture is beginning to increase and we are seeing more storms. I have tried several times this year to get great photographs of storms and lightning but my success rate has been pretty low.

Here are a few photographs from the past week.

Clouds develop across the whole sky in Sedona.
Clouds develop across the whole sky in Sedona.
An outflow boundary arrives and thunderstorms develop within a few minutes.
An outflow boundary arrives and thunderstorms develop within a few minutes.
A distant thunderstorm seen from Wupatki National Monument.
A distant thunderstorm seen from Wupatki National Monument.
Mid-afternoon lightning near Mormon Lake.
Mid-afternoon lightning near Mormon Lake.

And, finally we have a time lapse of the same storm that produced the lightning above. The video is 200x real time; from the motion it can be seen that the storm has some slow rotation. This storm moved off the higher terrain and became severe as it neared the Camp Verde area.

The weather models have been consistent with forecasting a significant increase in storm activity next week.

The 2020 nonsoon-Monsoon

A thin band of clouds partially blocks the sun and creates an array of crepuscular rays of light.

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.

Convection

Early stages of convection over the San Francisco Peaks as viewed from Marshall Lake.
Early stages of convection over the San Francisco Peaks as viewed from Marshall Lake.

A time-lapse movie shows that the ducks are more interesting than the convection.

Developing Cb's over the San Francisco Peaks.
Developing Cb’s over the San Francisco Peaks.
Small cumulus clouds over the Painted Desert.
Small cumulus clouds over the Painted Desert.
A weak thunderstorm near Two Guns, Arizona.
A weak thunderstorm near Two Guns, Arizona.
A well-developed thunderstorm over the Mogollon Rim viewed from Sedona.
A well-developed thunderstorm over the Mogollon Rim viewed from Sedona.

Rainbows

Full rainbows eluded me this year butI did manage to photograph a rainbow segment.

Rainbow segment over the North Rim of Grand Canyon.
Rainbow segment over the North Rim of Grand Canyon.

Lightning

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.

Lightning illuminates the interior of Grand Canyon.
Lightning illuminates the interior of Grand Canyon.
In-cloud lightning illuminates a small Cb near the Grand Canyon. I was trying to photograph the comet so I got lucky with this storm.
In-cloud lightning illuminates a small Cb near the Grand Canyon. I was trying to photograph the comet so I got lucky with this storm.
Lightning at sunset over the Mogollon Rim viewed from Sedona.
Lightning at sunset over the Mogollon Rim viewed from Sedona.
Weak storms over the San Francisco Peaks produced these two bolts of lightning.
Weak storms over the San Francisco Peaks produced these two bolts of lightning.
In-cloud lightning partially illuminates Grand Canyon while the nearly-full Moon provides additional illumination.
In-cloud lightning partially illuminates Grand Canyon while the nearly-full Moon provides additional illumination.

Sunsets

And when there is no lightning and no rainbow, one can be content with the sunset.

A small rain shaft is illuminated by the setting sun.
A small rain shaft is illuminated by the setting sun.
Distant rain catches the last light of the sun and provides backlighting for the Cockscomb.
Distant rain catches the last light of the sun and provides backlighting for the Cockscomb.
A thin band of clouds partially blocks the sun and creates an array of crepuscular rays of light.
A thin band of clouds partially blocks the sun and creates an array of crepuscular rays of light.
The sun sets over ruins in Wupatki National Monument.
The sun sets over ruins in Wupatki National Monument.
The setting sun illuminates both Cathedral Rock and the clouds above.
The setting sun illuminates both Cathedral Rock and the clouds above.

Miscellaneous

Crepuscalar Rays---Wupatki National Monument.
Crepuscalar Rays—Wupatki National Monument.
Crepuscalar Rays---San Francisco Peaks.
Crepuscalar Rays—San Francisco Peaks.
Even thought it is supposed to be the wet and rainy season, we still managed to get cap clouds on the high peaks with stars above.
Even thought it is supposed to be the wet and rainy season, we still managed to get cap clouds on the high peaks with stars above.

Perhaps 2021 will be a normal monsoon year.

Lightning at Sunset

It’s been a challenging season for storm photography. First was a late start to the North American Monsoon. And, then, just as it was finally ramping up it shut down quickly. Current model forecasts suggest at least another week until it ramps up again.

This storm eventually produced lightning after sunset.
This storm eventually produced lightning after sunset.
Sunset and lightning north of Sedona.
Sunset and lightning north of Sedona.
Evening twilight colors and lightning.
Evening twilight colors and lightning.

A bit of moisture managed to produce some thunderstorms right around sunset. And there was enough lightning to make it worthwhile to be there and get some photographs.

Comet C/2020 F3 (NEOWISE)—VII

The waxing Moon is getting brighter in the evening sky and this makes it more difficult to see Comet C/2020 F3 (NEOWISE). In fact, I was unable to see it with the unaided eye but both binoculars and long-exposure photographs easily brought out the comet.

Comet C/2020 F3 (NEOWISE) above Grand Canyon.
Comet C/2020 F3 (NEOWISE) above Grand Canyon.

On the other hand, the presence of the first-quarter Moon illuminates the inner canyon while the comet is faintly visible above.

The image is a composite. The first image is on a fixed tripod to get a sharp result of the moonlit canyon. The second image is on a tracker to get sharp points for the stars and comet. The two images are then combined. Camera settings are 24mm, ƒ/4, 120 seconds, ISO 400.

Thunderstorm with lightning near Grand Canyon.
Thunderstorm with lightning near Grand Canyon.

As a bonus, a late evening thunderstorm developed just west of Page and moved to the northeast while producing a lot of lightning. Although no cloud-to-ground strokes were noted, the lightning easily illuminated the cloud from the inside.

Sunset with crepuscular rays over Grand Canyon.
Sunset with crepuscular rays over Grand Canyon.

Second bonus: there was a nice sunset, too.