Kitty and Bill in Hilo Hawaii

Sent: Wednesday, November 26, 2003 2:35 PM
Subject: [Rockhounds] Rotor clouds

Hi List,
This isn't about rocks, but it is science, and involves mountains. (Note: I usually try to give measurements in metric, but I may not succeed all the time in this report.)

Tuesday morning Bill and I awoke to an astonishing sight in the sky. At dawn (6:30am) there was one huge altocumulus lenticular cloud eastward and obviously downwind from Mauna Kea (which is 14,000 ft/ 42,000 m. high). The first I noticed anything strange was when I saw an orange glow on the tile floor of the lanai (deck) outside our bedroom, which faces to the west. With the sun coming up on the opposite side of the house, I wondered where this glow could be coming from. I looked out at the mountain and saw four orange/white dots, which I recognized as sunrise light reflecting off some of the telescope domes there. Then I stepped out to get a better look at the sky and saw an enormous cloud, which was glowing orange on its edges and reflecting that color onto our tile. The underside of the cloud, however, was dark gray---almost black---and patterned with lines forming a spiral. I expected to hear deep threatening organ music! I also thought of the movie "Independence Day" with the image of an alien spaceship descending. To my left---southward---was a smaller and similar cloud closer to Mauna Loa. I ran to tell Bill (who had gotten up before dawn---the time his brain works best---to work on research) and he grabbed his camera but found it was out of film, ran back in the house to put in a new role, and got back outside to get a few shots but without the orange color. Meanwhile I had grabbed my digital camera, but I also was too late to get very much of the color.

We had already planned to drive to the west side of the island to Kona for shopping for Thanksgiving dinner supplies, so we left at 9am and drove around the north route. That meant that we went up the east coast of the island continuing north and then west, then gradually southwest and finally south so we made a semicircle around the north side of Mauna Kea. We usually divide driving so one of us takes the 2-hour duty one way, and the other does the return. It was my turn to drive over, and I had to concentrate to make sure I was paying proper attention to the road because the huge clouds were still there---3 hours later---and were spectacular! There was also a smaller cloud to the north that seemed to act like a baby trying to keep in close touch by reaching a cloudy tendril towards its "mother." As we proceeded around the north end of the island the clouds looked (at our left) like great bull-nosed marine mammals, heads toward the east, tails streaming west.

When we reached the west coast and were heading south, we were able to see the clouds head on, and at that point they had the true appearance of giant lenticular clouds, which is like a disc---or a soft-edged can of tuna---and suggests even more an alien space ship. The one closest to Mauna Kea was the most enormous---Bill thinks it must have been 10 miles (15 km?) wide and definitely higher than the mountain---looked like an uneven stack of fuzzy pancakes, tilted slightly to the north. That tilt gave it an especially ominous appearance, like a space ship taking a final turn to zoom in for attack! The smaller one we had originally seen close to Mauna Loa at 6:30 am, was now another large fuzzy pancake stack, with several white and dark gray layers. And the "baby" was by now nearly half as large as its "mother. The rest of the sky showed a great assortment of cloud types: there was a thick layer of puffy cumulous over each of the mountains (Mauna Kea, Mauna Loa, Hualalai, Kohala, and also Hale'akala visible across the channel on Maui), high cirrus in mare's tail form showed in different directions at different altitudes, there were a few small lenticular clouds, and near the ocean it was raining here and there.

The Hawaii Tribune Herald had a front-page photo of the largest cloud this morning. Various news sources say that yesterday winds gusted to 80 mph with wind chill to -20 degrees f. on the mountain summits. They say there is probably snow to as much as five feet deep on Mauna Kea and possibly Mauna Loa also, but no one has been able to get up to either location to look because the roads are too icy.

Aloha, and Happy Thanksgiving to all those who celebrate this holiday.


Here is the big altocumulus lenticular cloud over our house. Unfortunately the power lines mar it artistically. There is some of the sunrise color left; earlier it was brilliant orange. The small arm going off to the right went to a much smaller cloud I called The Baby in my earlier report. The arm at the left went over to the cloud that formed behind Mauna Loa, and will be shown in the next picture.

This is the smaller cloud that was formed by Mauna Loa. The arm extending to the right connected it to the Mauna Kea cloud. Again, it was more brilliant orange a minute or two earlier. You can see a little of the "pancake stack" effect. The two thin clouds on top, are more like "standard" lenticular clouds that are seen routinely on windy days in many locations. But the lower, yellow part is dense, thick, and has more of the "tuna can" appearance.

We visited the Kilauea volcano and saw lava pouring into the sea; read our trip report.

Current date and time is Friday, 22-Sep-2017 07:25:01 EDT and the Greenwich date and time is Friday, 22-Sep-2017 11:25:01 GMT. You are viewing this page from and are visitor number 324. This page was first published on 29 Nov 2003 and was last updated on Sunday, 30-Nov-2003 18:06:16 EST.