Barnes Bend Acess Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Barnes Bend Acess Area clear sky chart from 2005-11-05 to 2017-10-16.

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
52%
15229
25%
47016
19%
15186
59%
15186
31%
27767

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
32%
720
27%
2243
12%
716
47%
716
25%
1362
January16th to endNight
29%
768
26%
2304
13%
768
41%
768
23%
1529
February1st to 15thNight
34%
704
26%
2112
12%
701
45%
701
28%
1300
February16th to endNight
29%
631
27%
1893
12%
631
40%
631
27%
1152
March1st to 15thNight
31%
720
21%
2160
12%
720
40%
720
27%
1362
March16th to endNight
42%
617
26%
2005
17%
617
52%
617
31%
1152
April1st to 15thNight
43%
539
26%
1797
18%
539
55%
539
32%
984
April16th to endNight
47%
540
29%
1800
21%
540
60%
540
36%
943
May1st to 15thNight
53%
540
22%
1731
16%
540
62%
540
32%
1002
May16th to endNight
70%
561
25%
1682
21%
561
74%
561
38%
964
June1st to 15thNight
71%
540
17%
1620
15%
540
72%
540
34%
960
June16th to endNight
76%
540
23%
1461
20%
540
77%
540
43%
840
July1st to 15thNight
79%
510
17%
1391
17%
510
80%
510
38%
850
July16th to endNight
74%
564
16%
1739
17%
531
76%
531
31%
1014
August1st to 15thNight
79%
539
18%
1788
21%
536
80%
536
35%
1006
August16th to endNight
70%
573
21%
1910
25%
573
71%
573
26%
1200
September1st to 15thNight
63%
570
23%
1830
25%
570
65%
570
29%
1117
September16th to endNight
69%
717
30%
1980
25%
717
71%
717
40%
1160
October1st to 15thNight
62%
720
34%
1980
25%
720
68%
720
44%
1102
October16th to endNight
54%
708
35%
2138
29%
708
61%
708
39%
1151
November1st to 15thNight
53%
700
31%
2276
25%
700
63%
700
37%
1219
November16th to endNight
46%
720
29%
2340
22%
720
57%
720
32%
1310
December1st to 15thNight
40%
720
24%
2340
18%
720
48%
720
26%
1411
December16th to endNight
31%
768
20%
2496
14%
768
39%
768
19%
1677

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
11%5%25%5%35%5%5%7%43%
48379
Night
11%42442445%7%47%
47219
TransparencyDay
39%410%20%19%5%
48085
Night
35%310%20%21%8%
47018
SeeingDay
12%5%15%24%26%15%
5450
Night
13%6%20%30%23%5%
15231

By Month

Percentage Cloud Cover SE (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
19%6%2432333445%
1692
16th to endDay
18%6%23322335%48%
1920
February1st to 15thDay
15%7%25%323345%45%
1750
16th to endDay
18%6%25%423325%43%
1580
March1st to 15thDay
16%7%35%423435%41%
1800
16th to endDay
11%5%25%5%2446%6%43%
2227
April1st to 15thDay
13%4234245%5%6%45%
2151
16th to endDay
8%415%5%3445%6%49%
2160
May1st to 15thDay
12%5%25%425%5%47%43%
2217
16th to endDay
7%425%5%36%6%6%8%42%
2431
June1st to 15thDay
6%425%5%5%7%7%7%9%38%
2340
16th to endDay
5%4245%35%6%7%9%44%
2492
July1st to 15thDay
8%326%7%5%8%7%9%9%31%
2484
16th to endDay
6%427%7%5%8%7%8%10%31%
2306
August1st to 15thDay
6%4148%47%6%8%10%36%
2160
16th to endDay
10%6%26%7%46%5%6%9%32%
2292
September1st to 15thDay
12%5%35%5%35%5%5%7%39%
2117
16th to endDay
11%424424446%50%
1980
October1st to 15thDay
9%425%42335%5%53%
1977
16th to endDay
10%423322335%59%
1753
November1st to 15thDay
11%31332324457%
1582
16th to endDay
14%423423335%51%
1620
December1st to 15thDay
16%7%34423446%41%
1620
16th to endDay
21%9%35%414236%36%
1728
January1st to 15thNight
15%6%24323335%48%
2243
16th to endNight
18%6%35%5%3423441%
2304
February1st to 15thNight
14%6%2442445%5%46%
2103
16th to endNight
16%434423335%48%
1893
March1st to 15thNight
16%5%14424436%44%
2160
16th to endNight
12%4244235%5%5%49%
2005
April1st to 15thNight
10%424324348%51%
1797
16th to endNight
7%31432445%8%54%
1800
May1st to 15thNight
11%32442445%8%49%
1730
16th to endNight
5%423435%5%5%9%50%
1682
June1st to 15thNight
5%4145%35%6%8%11%43%
1620
16th to endNight
3223435%49%13%46%
1461
July1st to 15thNight
4225%6%36%6%8%9%44%
1473
16th to endNight
5%3246%36%6%9%12%39%
1858
August1st to 15thNight
5%3135%25%7%9%13%42%
1800
16th to endNight
7%425%6%36%6%6%10%39%
1910
September1st to 15thNight
10%426%5%3445%9%43%
1830
16th to endNight
7%42442445%7%52%
1980
October1st to 15thNight
10%313312446%57%
1980
16th to endNight
13%422211235%60%
2138
November1st to 15thNight
11%31332435%6%55%
2276
16th to endNight
12%5%14423335%53%
2340
December1st to 15thNight
15%6%25%423336%46%
2340
16th to endNight
20%7%35%5%2444437%
2496

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
44%25%18%22%6%
1693
16th to endDay
40%15%22%22%7%
1920
February1st to 15thDay
42%25%23%19%6%
1752
16th to endDay
45%25%16%23%6%
1580
March1st to 15thDay
45%38%18%18%6%
1800
16th to endDay
39%38%22%22%3
2228
April1st to 15thDay
37%28%21%21%7%
2151
16th to endDay
34%39%23%25%4
2160
May1st to 15thDay
39%311%18%22%4
2217
16th to endDay
36%414%24%17%1
2435
June1st to 15thDay
38%5%14%25%14%1
2340
16th to endDay
33%5%15%23%17%3
2492
July1st to 15thDay
41%8%19%18%9%2
2338
16th to endDay
42%7%19%20%9%
2162
August1st to 15thDay
38%7%18%20%12%3
2148
16th to endDay
45%7%14%19%9%3
2292
September1st to 15thDay
41%5%12%20%14%5%
2117
16th to endDay
34%49%22%21%8%
1980
October1st to 15thDay
32%36%21%24%12%
1977
16th to endDay
29%2315%37%12%
1753
November1st to 15thDay
30%25%22%28%10%
1582
16th to endDay
35%27%18%26%9%
1620
December1st to 15thDay
43%29%21%16%6%
1620
16th to endDay
51%18%18%15%4
1728
January1st to 15thNight
39%25%18%28%6%
2243
16th to endNight
46%2216%23%8%
2304
February1st to 15thNight
40%16%19%22%9%
2112
16th to endNight
39%2420%23%9%
1893
March1st to 15thNight
41%28%18%21%8%
2160
16th to endNight
34%38%24%24%5%
2005
April1st to 15thNight
32%29%22%22%9%
1797
16th to endNight
27%410%24%26%7%
1800
May1st to 15thNight
33%411%19%22%8%
1731
16th to endNight
30%413%26%19%5%
1684
June1st to 15thNight
32%6%16%23%17%2
1620
16th to endNight
26%5%20%24%18%3
1461
July1st to 15thNight
28%9%24%24%9%3
1391
16th to endNight
31%8%25%23%9%1
1739
August1st to 15thNight
28%7%22%22%14%4
1788
16th to endNight
37%8%16%20%13%3
1910
September1st to 15thNight
37%414%20%15%6%
1830
16th to endNight
30%49%22%23%9%
1980
October1st to 15thNight
27%38%21%23%16%
1980
16th to endNight
29%2313%31%19%
2138
November1st to 15thNight
30%25%17%28%15%
2276
16th to endNight
34%25%19%24%14%
2340
December1st to 15thNight
40%210%20%21%5%
2340
16th to endNight
49%26%16%18%5%
2496

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
18%12%31%24%10%3
90
16th to endDay
16%26%39%13%31
96
February1st to 15thDay
14%22%34%25%3
90
16th to endDay
18%19%34%23%3
81
March1st to 15thDay
26%22%30%15%5%
90
16th to endDay
18%9%27%26%17%
243
April1st to 15thDay
15%11%25%25%18%2
270
16th to endDay
11%6%24%32%20%4
270
May1st to 15thDay
16%8%17%31%17%8%
288
16th to endDay
7%319%30%24%15%
331
June1st to 15thDay
9%10%22%32%24%
315
16th to endDay
7%27%29%29%22%
467
July1st to 15thDay
6%15%25%37%23%
442
16th to endDay
7%1216%31%39%
326
August1st to 15thDay
10%215%39%30%
313
16th to endDay
13%318%36%26%
332
September1st to 15thDay
14%26%18%37%20%
315
16th to endDay
10%15%30%38%14%
314
October1st to 15thDay
12%18%32%27%8%
312
16th to endDay
13%422%31%23%6%
99
November1st to 15thDay
20%436%23%14%1
90
16th to endDay
10%14%35%22%16%1
90
December1st to 15thDay
27%7%37%15%8%2
90
16th to endDay
32%15%27%14%7%3
96
January1st to 15thNight
19%14%29%26%8%
720
16th to endNight
21%12%32%29%4
768
February1st to 15thNight
19%10%31%32%6%
704
16th to endNight
18%13%33%28%4
631
March1st to 15thNight
18%11%33%26%9%
720
16th to endNight
14%8%29%29%16%
617
April1st to 15thNight
11%10%31%30%15%
539
16th to endNight
9%6%30%35%15%1
540
May1st to 15thNight
13%422%33%22%3
540
16th to endNight
8%212%37%34%5%
563
June1st to 15thNight
7%7%33%40%10%
540
16th to endNight
325%28%45%14%
540
July1st to 15thNight
31230%45%17%
510
16th to endNight
5%1426%41%22%
564
August1st to 15thNight
7%321%48%18%
539
16th to endNight
9%422%46%15%
573
September1st to 15thNight
13%28%25%38%11%
570
16th to endNight
10%19%34%38%6%
717
October1st to 15thNight
12%218%30%30%5%
720
16th to endNight
14%6%17%31%25%4
708
November1st to 15thNight
13%5%22%32%21%4
700
16th to endNight
15%7%26%34%15%1
720
December1st to 15thNight
20%9%25%33%11%
720
16th to endNight
25%10%26%29%7%
768
Page generated at 2017-10-17 15:35:18. Version ac04

Copyright 2017 A. Danko


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