Don Olson in Yosemite       
         Don Olson                    Russell Doescher, Roger Sinnott (Sky & Telescope)      Moonbow  May 11, 2006
   Department of Physics             Kellie Beicker, Ashley Ralph, and Don Olson           Photo by Robert Stavers
   Texas State University                at the Lower Yosemite Fall Viewing Area               www.galleriehare.com

MOONBOW PREDICTIONS FOR 2008 & 2009 & 2010
based on the methods described in this article:
       "Moonbows over Yosemite," Sky & Telescope, May 2007
related story:
          http://www.txstate.edu/news/news_releases/news_archive/2007/04/Moonbow041207.html

visual observers generally report that moonbows appear "white," "gray," or "silvery"
but time-exposure photographs reveal the full palette of colors

PHOTOGRAPHS OF MOONBOWS AT LOWER YOSEMITE FALL
series by CK Yip showing movement of the moonbow as the Moon rose on April 18, 2008
http://www.flickr.com/photos/25863569@N04/sets/72157604672244579/
moonbow photograph by Mark Heliger on May 29, 2007
http://www.thenewphotography.com/moonbow.htm
moonbow photograph by Jennifer Doerrie on April 30, 2007
http://www.myparkphotos.com/Members/?object=member&function=photo_homepage&photo_id=25646
moonbow photograph by Jia Liu on May 12, 2006
http://thruthefinder.com/picture.php?gallery=naturescapes&index=51
moonbow photograph by Jia Liu on April 13, 2006
http://thruthefinder.com/picture.php?gallery=naturescapes&index=42
moonbow photograph by Robert Stavers on May 11, 2006
http://www.galleriehare.com/galleriehare/water_mountains.html#
moonbow photograph by Kim Steinbacher on May 22, 2005
http://www.kimsteinbacher.com/gallery/photo.php?photo=576
moonbow photograph by Mark Bright near midnight on May 23-24, 2005
http://sunsetinn-yosemitecabins.com/
moonbow photograph by Bill Pruitt on May 4, 2004
http://www.pbase.com/dakota49/image/28904297
moonbow photographs by Grant Johnson in 1995, 1996, and 2006
http://www.grantjohnson.net/gallery.php?gallery_id=3


MOONBOW PREDICTIONS FOR 2008
LOWER YOSEMITE FALL
 
OBSERVING LOCATION:   VIEWING AREA, TERRACE AT THE WEST END OF THE BRIDGE
NEAR THE BASE OF LOWER YOSEMITE FALL
 
 
DATE
IN
2008 		TIMES
(PACIFIC
DAYLIGHT
TIME) 		LUNAR
PHASE
  		REMARKS
April 18
(Fri) 		8:20pm
(Fri)
to
10:15pm
(Fri) 		 99%
waxing 		moonbow is already in progress when sky gets dark enough at about 8:20pm
April 19
(Sat) 		8:30pm
(Sat)
to
11:30pm
(Sat) 		 100%
  		brightest moonbow for 2008
moonbow is already in progress when sky gets dark enough at about 8:30pm
(full Moon occurs at 3:25am PDT on April 20)
night of
April 20-21
(Sun-Mon) 		11:00pm
(Sun)
to
12:40am
(Mon) 		   99%
waning 		 
night of
April 21-22
(Mon-Tues) 		12:17am
(Tues)
to
1:45am
(Tues) 		   96%
waning 		moonbow appears just as Moon clears south rim of valley between Moran Point and Sentinel Dome
May 17
(Sat) 		8:50pm
(Sat)
to
10:30pm
(Sat) 		  97%
waxing 		moonbow is already in progress when sky gets dark enough at about 8:50pm
May 18
(Sun) 		10:06pm
(Sun)
to
11:40pm
(Sun) 		 99%
waxing 		moonbow appears just as Moon clears south rim of valley between Moran Point and Sentinel Dome
night of
May 19-20
(Mon-Tues) 		11:14pm
(Mon)
to
12:40am
(Tues) 		  100% moonbow appears just as Moon clears south rim of valley near Sentinel Dome
(full Moon occurs at 7:11pm PDT on May 19)
night of
May 20-21
(Tues-Wed) 		12:17am
(Wed)
to
1:40am
(Wed) 		  98%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
June 16
(Mon) 		10:13pm
(Mon)
to
11:25pm
(Mon) 		  98%
waxing 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
night of
June 17-18
(Tues-Wed) 		11:12pm
(Tues)
to
12:20am
(Wed) 		 100% moonbow appears just as Moon clears south rim of valley near Sentinel Dome
(full Moon occurs at 10:30am PDT on June 18)
night of
June 18-19
(Wed-Thurs) 		12:01am
(Thurs)
to
1:10am
(Thurs) 		  99%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
night of
June 19-20
(Thurs-Fri) 		12:34am
(Fri)
to
1:50am
(Fri) 		  97%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome

 
CONDITIONS REQUIRED TO OBSERVE A MOONBOW IN LOWER YOSEMITE FALL
for observers at the viewing area, the terrace just west of the bridge near the base of Lower Yosemite Fall
 
1.  bright moonlight (nearly-full Moon)
2.  Moon risen above the south rim of the valley (so moonlight can strike Lower Yosemite Fall)
3.  sufficient mist and spray (during snowmelt runoff season: April, May, June, sometimes July)
4.  clear skies
5.  dark skies (Sun more than 9 degrees below the horizon)
6.  geometry (the angle between the “anti-lunar direction” [observer’s shadow cast by the moonlight] and the
     direction toward the base of Lower Yosemite Fall must be near the “rainbow angle” of 42 degrees)
 
NOTE
If the snowmelt runoff is unusually strong, then moonbows could appear earlier and last longer than the predicted times. 
If the snowmelt runoff is unusually weak, then moonbows would be visible for shorter intervals than the predicted times.

NOTE
Feedback from photographers / observers regarding the accuracy of our predictions for 2008 is welcomed
by Don Olson at
dolson@txstate.edu

LINKS ABOUT OUR PREDICTIONS FOR
THE AUTUMN MOON ENCORE EVENT
ON GLACIER POINT

http://antwrp.gsfc.nasa.gov/apod/ap051215.html
http://skyandtelescope.com/news/article_1595_1.asp
http://www.yosemite.org/newsroom/clips2005/september/091605.htm
http://skyandtelescope.com/aboutsky/pressreleases/article_1572_1.asp

Autumn Moon Encore by Russell Doescher

Autumn Moon Encore        Glacier Point, Yosemite       September 15, 2005

            (photograph by Russell Doescher, Texas State University)


MOONBOW PREDICTIONS FOR 2009
LOWER YOSEMITE FALL
 
OBSERVING LOCATION:   VIEWING AREA, TERRACE AT THE WEST END OF THE BRIDGE
NEAR THE BASE OF LOWER YOSEMITE FALL

DATE
IN
2009 		TIMES
(PACIFIC
DAYLIGHT
TIME) 		LUNAR
PHASE
  		REMARKS
April 7
(Tues) 		8:10pm
(Tues)
to
9:01pm
(Tues) 		98%
waxing 		moonbow is already in progress when sky gets dark enough at about 8:10pm
April 8
(Wed) 		8:10pm
(Wed)
to
10:50pm
(Wed) 		100%
  		brightest moonbow for 2009
moonbow is already in progress when sky gets dark enough at about 8:10pm
(full Moon occurs at 7:56am PDT on April 9)
night of
April 9-10
(Thurs-Fri) 		10:00pm
(Thurs)
to
12:15am
(Fri) 		99%
waning 		depending on snowmelt runoff, moonbow may even be visible as early as 9:15pm on Thursday evening
night of
April 10-11
(Fri-Sat) 		11:50pm
(Fri)
to
1:25am
(Sat) 		97%
waning 		 
May 6
(Wed) 		8:40pm
(Wed)
to
10:00pm
(Wed) 		96%
waxing 		moonbow is already in progress when sky gets dark enough at about 8:40pm
May 7
(Thurs) 		9:25pm
(Thurs)
to
11:15pm
(Thurs) 		99%
waxing 		 
night of
May 8-9
(Fri-Sat) 		10:45pm
(Fri)
to
12:25am
(Sat) 		100% (full Moon occurs at  9:01pm PDT on May 8)
night of
May 9-10
(Sat-Sun) 		12:01am
(Sun)
to
1:25am
(Sun) 		98%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
June 5
(Fri) 		9:50pm
(Fri)
to
11:15pm
(Fri) 		98%
waxing 		moonbow appears just as Moon clears south rim of valley between Moran Point and Sentinel Dome
night of
June 6-7
(Sat-Sun) 		10:52pm
(Sat)
to
12:15am
(Sun) 		100% moonbow appears just as Moon clears south rim of valley near Sentinel Dome
(full Moon occurs at 11:12am PDT on June 7)
night of
June 7-8
(Sun-Mon) 		11:46pm
(Sun)
to
1:10am
(Mon) 		100% moonbow appears just as Moon clears south rim of valley near Sentinel Dome
 
night of
June 8-9
(Mon-Tues) 		12:32am
(Tues)
to
1:50am
(Tues) 		98%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome


MOONBOW PREDICTIONS FOR 2010
LOWER YOSEMITE FALL
 
OBSERVING LOCATION:
VIEWING AREA, TERRACE AT THE WEST END OF THE BRIDGE
NEAR THE BASE OF LOWER YOSEMITE FALL
  
DATE
IN
2010 		TIMES
(PACIFIC
DAYLIGHT
TIME) 		LUNAR
PHASE
  		REMARKS
March 28
(Sun) 		8:00pm
(Sun)
to
9:00pm
(Sun) 		99%
waxing 		moonbow is already in progress when sky gets dark enough at about 8:00pm
March 29
(Mon) 		8:22pm
(Mon)
to
11:10pm
(Mon) 		100%
  		possibly brightest moonbow for 2010
(depending on snowmelt runoff)
moonbow appears just as Moon rises into sky
between Half Dome and Mount Starr King
(full Moon occurs at 7:25pm PDT on March 29)
night of
March 30-31
(Tues-Wed) 		9:26pm
(Tues)
to
12:45am
(Wed) 		98%
waning 		moonbow appears just as Moon rises into sky
between Half Dome and Mount Starr King
April 26
(Mon) 		8:30pm
(Mon)
to
10:15pm
(Mon) 		98%
waxing 		moonbow is already in progress when sky gets dark enough at about 8:30pm
April 27
(Tues) 		9:45pm
(Tues)
to
11:40pm
(Tues) 		100% bright moonbow
(full Moon occurs at 5:18am PDT on April 28)
night of
April 28-29
(Wed-Thurs) 		11:15pm
(Wed)
to
12:55am
(Thurs) 		99%
waning 		 
night of
April 29-30
(Thurs-Fri) 		12:38am
(Fri)
to
2:00am
(Fri) 		96%
waning 		moonbow appears just as Moon clears south rim of valley between Moran Point and Sentinel Dome
May 25
(Tues) 		9:00pm
(Tues)
to
10:35pm
(Tues) 		96%
waxing 		moonbow is already in progress when sky gets dark enough at about 9:00pm
May 26
(Wed) 		10:18pm
(Wed)
to
11:45pm
(Wed) 		99%
waxing 		moonbow appears just as Moon clears south rim of valley between Moran Point and Sentinel Dome
night of
May 27-28
(Thurs-Fri) 		11:25pm
(Thurs)
to
12:50am
(Fri) 		100% moonbow appears just as Moon clears south rim of valley near Sentinel Dome
 
night of
May 28-29
(Fri-Sat) 		12:19am
(Sat)
to
1:45am
(Sat) 		98%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
night of
May 29-30
(Sat-Sun) 		1:06am
(Sun)
to
2:30am
(Sun) 		94%
waning 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
June 23
(Wed) 		9:15pm
(Wed)
to
10:30pm
(Wed) 		95%
waxing 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
(brightness and duration depend on snow season and snowmelt runoff)
June 24
(Thurs) 		10:12pm
(Thurs)
to
11:30pm
(Thurs) 		98%
waxing 		moonbow appears just as Moon clears south rim of valley near Sentinel Dome
(brightness and duration depend on snow season and snowmelt runoff)
night of
June 25-26
(Fri-Sat) 		11:02pm
(Fri)
to
12:20am
(Sat) 		100% possibly brightest moonbow for 2010
(depending on snowmelt runoff)
moonbow appears just as Moon clears south rim of valley near Sentinel Dome
(partial lunar eclipse begins at 3:17am PDT
  on June 26)
night of
June 26-27
(Sat-Sun) 		11:40pm
(Sat)
to
1:00am
(Sun) 		99%
waning 		(brightness and duration depend on snow season and snowmelt runoff)
night of
June 27-28
(Sun-Mon) 		12:05am
(Mon)
to
1:35am
(Mon) 		97%
waning 		(brightness and duration depend on snow season and snowmelt runoff)
 

LINKS

Texas State University Honors Program
http://www.txstate.edu/honors/

Christopher Olson, JD, Attorney at Law, Maui, Hawaii
http://hawaiiattorneyonline.com/