The heavens declare the glory of God;
the skies proclaim the work of his hands.
-Psalm 19:1

Do you know that God controls the clouds and makes his lightning flash?
-Job 37:15



Thursday, August 06, 2009

Rolling with the roll cloud

SKY WATCH FRIDAY time! I am SUPER busy with stimulus yuck, so I might not get a chance to say hi. Please don't take offense. Thanks for the visit in advance. Our hosts: Klaus Sandy Ivar Wren Louise Fishing Guy

Thanks, also,to Dot and Tom, who were instrumental in the success of this blogging event. You should definitely come fly with us!

Last night, I had the rare privilege of shooting a roll cloud, as it approached my home just ahead of a severe warned cell that ended up remaining well north of me at its greatest intensity (are we surprised?) To the right, I have posted a radar capture of my best approximation of what it looked like at that precise moment.The roll cloud did offer and almost rolling appearance especially on its northeastern side, where the weather appeared the worst, and the cloud itself appeared closer to the ground. It rapidly approached and inundated us... with the rumble of thunder in the background, it gave an almost vicious feel, but I was loving every minute of it.

A Roll cloud (like a shelf cloud) is an example of an arcus cloud. An arcus cloud is a low, horizontal cloud formation associated with the leading edge of thunderstorm outflow, or occasionally with a cold front even in the absence of thunderstorms. Cool, sinking air from a storm cloud's downdraft spreads out across the surface with the leading edge called a gust front. This outflow undercuts warm air being drawn into the storm's updraft. As the cool air lifts the warm moist air, water condenses creating a cloud which often rolls with the different winds above and below (wind shear).

A roll cloud is a low, horizontal, tube-shaped, and relatively rare type of arcus cloud. They differ from shelf clouds by being completely detached from the thunderstorm base or other cloud features. Roll clouds usually appear to be "rolling" about a horizontal axis. They can be a sign of possible microburst activity.

~ source
I shot some video.
In other news... I haven't really focused on the Eastern Pacific Hurricane season because "generally" those storms don't pose a threat to land. Well, lo and behold, major Hurricane Felicia, currently a category 4 hurricane has her sites set on Hawaii... like a dead-on collision. Of course, a story like that becomes major news... "Major Hurricane Expected to Slam into Hawaii"... what they aren't emphasizing is that this major hurricane is forecast to weaken tremendously, if not dissipate by the time she gets to Hawaii. Forecast Track of Felicia shows Felicia as a Tropical Depression on approach to the Hawaiian Islands
AFTER DAY 3, THE HURRICANE SHOULD BE OVER SEA SURFACE TEMPERATURES LESS THAN 26C AND HEADING TOWARD INCREASING WESTERLY SHEAR. STEADY WEAKENING IS INDICATED IN THE FORECAST AT THAT TIME. ALL THE GLOBAL MODELS SHOW A MUCH WEAKER VORTEX AS THE CYCLONE APPROACHES THE HAWAIIAN ISLANDS...AND THE SHIPS MODEL EVEN DISSIPATES THE SYSTEM BY THAT TIME.
Be certain to read my post about "late blooming hurricanes" before letting your guard down for the Atlantic season.
Acts 27:25
So keep up your courage, men, for I have faith in God that it will happen just as he told me.


God bless,
~Dewdrop

26 comments:

  1. a good thursday.

    we see roll clouds here often. thanks for the info concerning. i never saw them in california.

    as always enjoy the info and wishing you a wonderful weekend.

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  2. a lovely series of photos, I have never heard of a roll cloud before?

    Gill in Canada

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  3. I Like the roll cloud photos and writeup'

    To see Skies over the Marsh, Click here.

    Come visit anytime,
    Troy and Martha

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  4. Terrific post Dew!
    Loved the video and was so glad you named the music - super.
    Don't work too hard. :)

    My post is here: Carletta’s Captures.

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  5. Those clouds look like they really have some heft to them!

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  6. Great photo´s and a interestings post again!Thank you for sharing!Have a nice weekend!

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  7. The clouds do look like they are rolling. Great shots.

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  8. AWESOME post and pictures AGAIN!
    LOVE your blog.
    Take care and Happy SWF

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  9. Great collection of photos for sky watch friday and video clip as well. Thanks for sharing with us all.

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  10. Wonderful capture of the roll cloud Dew and the video too.
    Thank you for all the information you give on your site. I find it very helpful.
    Have a good weekend.

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  11. Thanks for the information about roll clouds. I wonder if I would recognize one if I saw it. I'll try to remember your description. ;-)

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  12. Nice captures, i often see skies like this but here in holland it's kinda normal, but never with really heavy storms or beginning tornado's....

    Love your captures and your short film,

    Have a nice SWF

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  13. What an interesting sky formation. You really present the phenomen very well.

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  14. We had one of these here once. Never seen anything like it since. Of course I had no idea what it was. Always rely on you to name those clouds. weird and wonderful.

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  15. We had one of these here once. Never seen anything like it since. Of course I had no idea what it was. Always rely on you to name those clouds. weird and wonderful.

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  16. I love watching thunderstorms, but living on the Florida Gulf Coast, hurricanes not so much.

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  17. Hi. Thanks for the info. Its been raining out here and we have storms here and there. Our skies been like that.
    Great captures.

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  18. Spectacular cloud captures, they look so threatening though!

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  19. Your roll cloud almost looks like a wave crashing towards you. Nice captures and liked the video.

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  20. I love to see a storm literally rolling in!

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  21. Thank you for an informative post on the roll clouds.

    - celine
    http://indicainq8.wordpress.com/

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  22. Fascinating detail as always! I see these clouds formations quite a great deal lately! (I didn't know their name, however!)Sometimes they herald storm as you say, but they do look as though the sky is creeping closer to the earth!

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  23. Awesome shots. The information on roll cloud very new to me. Great.

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  24. Great series!
    It's always very impressive when a rollcloud comes over.

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Dew comment, please...