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Majestic Skies Ranch
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Majestic Skies Ranch clear sky chart from 2005-11-05 to 2017-05-24.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
56%
15260
33%
45910
21%
15217
67%
15217
47%
22824

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
50%
718
33%
2327
22%
716
65%
716
47%
1100
January16th to endNight
43%
768
37%
2496
22%
768
63%
768
47%
1168
February1st to 15thNight
47%
703
34%
2175
21%
700
63%
700
52%
1010
February16th to endNight
37%
632
39%
1894
16%
632
60%
632
50%
898
March1st to 15thNight
47%
720
36%
2034
19%
720
61%
720
49%
1006
March16th to endNight
47%
717
38%
2061
19%
717
63%
717
53%
980
April1st to 15thNight
38%
539
35%
1798
15%
539
62%
539
46%
800
April16th to endNight
38%
540
40%
1800
20%
540
67%
540
53%
747
May1st to 15thNight
45%
540
28%
1799
19%
539
61%
539
46%
835
May16th to endNight
57%
541
31%
1607
20%
540
69%
540
51%
789
June1st to 15thNight
60%
495
31%
1320
22%
495
67%
495
54%
685
June16th to endNight
71%
495
22%
1320
18%
495
73%
495
47%
733
July1st to 15thNight
75%
465
21%
1370
20%
465
75%
465
36%
804
July16th to endNight
80%
522
18%
1467
17%
489
80%
489
35%
862
August1st to 15thNight
83%
494
19%
1608
22%
491
83%
491
32%
939
August16th to endNight
81%
525
23%
1750
26%
525
82%
525
34%
972
September1st to 15thNight
69%
495
26%
1650
28%
495
72%
495
29%
989
September16th to endNight
74%
500
35%
1760
31%
500
82%
500
47%
806
October1st to 15thNight
64%
660
36%
1980
24%
660
72%
660
51%
960
October16th to endNight
65%
704
39%
2112
23%
704
76%
704
60%
933
November1st to 15thNight
59%
749
40%
2149
22%
749
72%
749
65%
943
November16th to endNight
56%
900
37%
2340
21%
900
65%
900
52%
1218
December1st to 15thNight
48%
900
36%
2427
18%
900
61%
900
52%
1240
December16th to endNight
41%
938
32%
2666
18%
938
53%
938
45%
1407

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
331332345%7%62%
46344
Night
321232345%7%63%
46107
TransparencyDay
21%5%9%18%27%18%
46040
Night
19%5%9%19%28%17%
45913
SeeingDay
6%11%24%31%20%5%
4933
Night
46%28%35%21%2
15264

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
2312222246%68%
1611
16th to endDay
5%312212345%67%
1728
February1st to 15thDay
2312212245%71%
1687
16th to endDay
132313337%68%
1580
March1st to 15thDay
2213424347%62%
1923
16th to endDay
221331335%6%67%
2162
April1st to 15thDay
2212213347%66%
2150
16th to endDay
22121233475%
2160
May1st to 15thDay
2112324446%64%
2151
16th to endDay
212213447%69%
2343
June1st to 15thDay
122135%5%8%68%
2310
16th to endDay
321322446%8%60%
2310
July1st to 15thDay
7%4246%347%7%10%41%
2166
16th to endDay
4435%6%46%7%9%10%36%
2285
August1st to 15thDay
5%3246%45%6%8%10%40%
2011
16th to endDay
5%325%6%36%5%7%10%43%
2100
September1st to 15thDay
8%6%25%435%5%6%7%43%
1980
16th to endDay
5%21332334465%
1865
October1st to 15thDay
432322224469%
1650
16th to endDay
21121222476%
1760
November1st to 15thDay
121212235%75%
1696
16th to endDay
331321222470%
1620
December1st to 15thDay
3412112336%68%
1530
16th to endDay
4412323435%63%
1566
January1st to 15thNight
3312213335%68%
2327
16th to endNight
4212113346%67%
2496
February1st to 15thNight
2412212347%68%
2165
16th to endNight
2213213346%67%
1894
March1st to 15thNight
221232335%7%65%
2034
16th to endNight
3212213335%71%
2061
April1st to 15thNight
3212213248%66%
1798
16th to endNight
2212212335%73%
1800
May1st to 15thNight
2213324346%64%
1799
16th to endNight
3112214348%66%
1607
June1st to 15thNight
12242345%8%62%
1320
16th to endNight
213435%6%7%8%55%
1320
July1st to 15thNight
5%3235%26%6%8%11%44%
1460
16th to endNight
3214436%6%8%14%43%
1575
August1st to 15thNight
4213335%8%10%12%43%
1617
16th to endNight
2223445%6%9%12%46%
1750
September1st to 15thNight
7%3245%35%6%7%9%44%
1650
16th to endNight
323323346%66%
1760
October1st to 15thNight
3212213346%68%
1980
16th to endNight
21221224376%
2112
November1st to 15thNight
11112246%75%
2149
16th to endNight
331222322470%
2340
December1st to 15thNight
5%32212336%67%
2427
16th to endNight
4412223347%61%
2666

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%38%20%37%12%
1612
16th to endDay
19%37%19%35%15%
1728
February1st to 15thDay
16%27%20%30%21%
1688
16th to endDay
16%2417%39%18%
1580
March1st to 15thDay
20%36%17%32%19%
1923
16th to endDay
17%25%16%35%22%
2162
April1st to 15thDay
17%36%16%33%22%
2150
16th to endDay
13%25%14%34%29%
2160
May1st to 15thDay
18%49%14%28%23%
2151
16th to endDay
15%5%6%16%25%30%
2346
June1st to 15thDay
13%48%16%24%33%
2310
16th to endDay
19%5%11%16%21%25%
2310
July1st to 15thDay
34%10%14%15%11%12%
2027
16th to endDay
33%13%18%21%11%1
2130
August1st to 15thDay
32%11%17%21%12%3
1996
16th to endDay
33%9%14%21%14%5%
2100
September1st to 15thDay
37%7%14%17%14%8%
1980
16th to endDay
21%5%7%19%26%19%
1865
October1st to 15thDay
19%38%15%30%22%
1650
16th to endDay
14%2418%36%22%
1760
November1st to 15thDay
12%17%20%37%19%
1696
16th to endDay
19%1418%35%19%
1620
December1st to 15thDay
17%38%30%30%10%
1530
16th to endDay
23%5%12%25%27%6%
1566
January1st to 15thNight
19%49%18%37%11%
2327
16th to endNight
18%46%18%40%12%
2496
February1st to 15thNight
17%27%21%29%20%
2175
16th to endNight
17%35%18%37%18%
1894
March1st to 15thNight
17%36%19%33%18%
2034
16th to endNight
16%25%16%36%21%
2061
April1st to 15thNight
17%36%17%33%21%
1798
16th to endNight
13%35%15%34%28%
1800
May1st to 15thNight
19%39%13%30%24%
1800
16th to endNight
16%6%8%15%24%28%
1609
June1st to 15thNight
17%49%15%17%34%
1320
16th to endNight
22%6%12%15%14%27%
1320
July1st to 15thNight
28%8%14%22%14%10%
1370
16th to endNight
27%10%22%24%13%1
1467
August1st to 15thNight
27%11%21%20%14%4
1608
16th to endNight
24%11%16%28%13%5%
1750
September1st to 15thNight
32%9%16%18%12%9%
1650
16th to endNight
19%48%19%26%20%
1760
October1st to 15thNight
17%5%8%17%28%23%
1980
16th to endNight
12%35%17%33%27%
2112
November1st to 15thNight
11%26%20%37%22%
2149
16th to endNight
19%25%16%33%22%
2340
December1st to 15thNight
18%38%26%29%12%
2427
16th to endNight
22%410%26%29%7%
2666

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
13%15%31%26%8%4
90
16th to endDay
7%21%37%21%9%2
96
February1st to 15thDay
314%28%32%21%
90
16th to endDay
419%33%29%12%
81
March1st to 15thDay
6%19%33%28%10%1
213
16th to endDay
7%21%37%22%6%3
288
April1st to 15thDay
9%28%30%23%6%1
269
16th to endDay
9%25%41%18%32
270
May1st to 15thDay
422%38%25%6%2
288
16th to endDay
311%37%30%16%
390
June1st to 15thDay
25%21%40%26%3
420
16th to endDay
3213%31%41%7%
420
July1st to 15thDay
7%9%39%36%7%
266
16th to endDay
7%5%26%35%23%
271
August1st to 15thDay
5%18%35%30%18%
255
16th to endDay
7%110%42%29%9%
268
September1st to 15thDay
10%214%40%25%5%
255
16th to endDay
3415%43%31%
151
October1st to 15thDay
8%5%22%37%20%5%
90
16th to endDay
7%421%34%18%13%
96
November1st to 15thDay
11%14%24%18%23%7%
90
16th to endDay
11%24%31%24%8%
90
December1st to 15thDay
5%17%34%31%8%2
90
16th to endDay
17%19%30%29%3
96
January1st to 15thNight
46%34%35%14%3
720
16th to endNight
5%9%38%30%15%1
768
February1st to 15thNight
48%36%36%12%1
704
16th to endNight
312%44%33%5%
632
March1st to 15thNight
213%34%34%13%
720
16th to endNight
211%36%37%11%
717
April1st to 15thNight
415%40%31%7%
539
16th to endNight
412%42%34%6%
540
May1st to 15thNight
37%40%39%9%
540
16th to endNight
2432%44%15%
542
June1st to 15thNight
2228%47%18%
495
16th to endNight
2117%44%30%2
495
July1st to 15thNight
46%37%46%3
465
16th to endNight
3423%59%9%
522
August1st to 15thNight
4421%57%11%
494
16th to endNight
25%29%54%7%
525
September1st to 15thNight
7%113%35%40%2
495
16th to endNight
4213%45%30%4
500
October1st to 15thNight
3423%42%22%3
660
16th to endNight
25%23%37%25%5%
704
November1st to 15thNight
25%30%36%22%2
749
16th to endNight
6%9%25%34%20%3
900
December1st to 15thNight
6%8%33%34%15%1
900
16th to endNight
8%10%36%33%9%1
938
Page generated at 2017-05-25 11:27:31. Version ac04

Copyright 2017 A. Danko


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