Category: Weather

Using Satellite Data to Anticipate a Great Sunset

This sunset from a few weeks ago was pretty spectacular. Drivers were pulling off the highway into the overlook area to get photographs. I overheard one person claiming this was a one-in-a-million sunset. That was probably an overstatement of several magnitudes. More likely, this was a one-in-a-hundred event, meaning you could see a sunset this great a few times a year.

Sunset viewed from Mormon Lake.
Sunset viewed from Mormon Lake.
Sunset details.
Sunset details.

I had been looking at satellite data that afternoon and saw a nice streak of high cirrus clouds moving across northern Arizona. The orientation of the clouds suggested that the sun might briefly appear below the clouds and illuminate the bottoms around and shortly after sunset.

Satellite image showing streak of cirrus clouds moving across northern Arizona.
Satellite image showing streak of cirrus clouds moving across northern Arizona.

So I headed out to Mormon Lake Overlook where there is a good view of the western sky and waited.

It worked out pretty well.

The 2020 nonsoon-Monsoon

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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.

Comet C/2020 F3 (NEOWISE)—IV

The comet continues to rise higher in the northwestern sky after sunset. It is now in a position so that I can get reflections of the comet in water at the same time that the comet is above the San Francisco Peaks. So I worked out the geometry and set up on Ashurst Lake, southeast of Flagstaff.

Comet C/2020 F3 (NEOWISE) over Ashurst Lake.
Comet C/2020 F3 (NEOWISE) over Ashurst Lake.

It didn’t work out for a couple of reasons. There was too much wind and the surface of the water remained ruffled rather than smooth. And then, as the comet was sinking lower in the sky and the winds began to diminsh clouds developed.

So, I’ll have to try this one again when I get better conditions.

Some Interesting Wave Clouds

For a few hours this morning (02 July 2020) the clouds were amazing. Laminar, wave-like clouds were visible across a portion of the sky and moving quickly to the north. Farther south, the sky remained clear. These clouds were apparently forming in a region of orographic uplift generated by the Mogollon Rim.

Wave clouds over Flagstaff.
Wave clouds over Flagstaff.
Wave clouds over Flagstaff.
Wave clouds over Flagstaff.
Wave clouds over Flagstaff.
Wave clouds over Flagstaff.

But these clouds weren’t actually a surprise. Yesterdays models were forecasting a thin layer of moisture around 700 mb with much drier conditions both above and below that level.

Observed sounding from KFGZ at 1200 UTC 02 July 2020
Observed sounding from KFGZ at 1200 UTC 02 July 2020
24-hour forecast sounding for KFLG for 1200 UTC 02 July 2020
24-hour forecast sounding for KFLG for 1200 UTC 02 July 2020

The GFS did a good job of forecasting both the thin layer of moisture and the stronger winds embedded in that layer. But where did those stronger winds and moisture originate?

HYSPLIT backward trajectories.
HYSPLIT backward trajectories.

A look back using backward trajectories from the HYSPLIT model reveals some interesting origins. Higher-level air parcels originated over the northeast Pacific while low-level parcels originated over the eastern Pacific. The water vapor satellite images shows both of these source regions to be very dry.

Water vapor satellite image from 1200 UTC 29 June 2020.
Water vapor satellite image from 1200 UTC 29 June 2020.

The moist layer had its origins along the Mexico coast. The water vapor image shows substantial moisture associated with Tropical Depression FOUR-E.

Tropical depression FOUR-E.
Tropical depression FOUR-E.

So the shallow mid-level moist layer had its origins in the remnants of a tropical disturbance. Very interesting!

A Late Winter Storm

A winter storm brought snow, clouds, and fog to some of my favorite photographic locations. The early morning sun lights up a band of clouds that encircles the San Francisco Peak. Below the peaks, fog lies in the low areas of both Upper and Lower Lake Mary.

Fog and clouds wrap around the San Francisco Peaks.
Fog and clouds wrap around the San Francisco Peaks.

A smaller area of fog sits in the corner of the Mormon Lake basin and partially obscures some of the old ranch buildings.

Fog and ranch buildings near Mormon Lake.
Fog and ranch buildings near Mormon Lake.
Reflections.
Reflections.

Finally, a small patch of grass pokes up from the still water of Lake Mary while fog blurs the background.