Galbreath Wildlands Preserve
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Galbreath Wildlands Preserve clear sky chart from 2005-11-05 to 2017-10-06.

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
58%
15365
26%
47142
21%
15327
64%
15327
36%
26219

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
53%
717
16%
2366
15%
716
56%
716
23%
1517
January16th to endNight
51%
768
25%
2496
25%
768
55%
768
26%
1558
February1st to 15thNight
48%
700
20%
2288
19%
700
52%
700
21%
1497
February16th to endNight
42%
632
20%
1939
15%
632
49%
632
24%
1255
March1st to 15thNight
45%
720
13%
1980
10%
720
47%
720
21%
1410
March16th to endNight
41%
768
18%
2112
12%
768
46%
768
26%
1391
April1st to 15thNight
37%
719
20%
1808
9%
719
44%
719
25%
1226
April16th to endNight
46%
705
24%
1785
9%
705
53%
705
40%
1028
May1st to 15thNight
52%
539
29%
1619
17%
539
62%
539
48%
787
May16th to endNight
58%
421
25%
1543
19%
420
68%
420
40%
704
June1st to 15thNight
54%
360
26%
1440
24%
360
68%
360
38%
639
June16th to endNight
65%
360
35%
1440
38%
360
77%
360
61%
503
July1st to 15thNight
83%
402
33%
1422
35%
402
87%
402
77%
474
July16th to endNight
87%
564
39%
1593
35%
531
90%
531
72%
641
August1st to 15thNight
87%
538
39%
1611
31%
535
90%
535
76%
631
August16th to endNight
85%
720
42%
1866
28%
720
88%
720
75%
833
September1st to 15thNight
85%
720
41%
1800
27%
720
88%
720
77%
820
September16th to endNight
76%
716
40%
1992
33%
716
82%
716
64%
903
October1st to 15thNight
66%
684
28%
2052
26%
684
73%
684
46%
1043
October16th to endNight
65%
704
30%
2112
30%
704
70%
704
39%
1162
November1st to 15thNight
56%
700
23%
2154
21%
700
62%
700
30%
1285
November16th to endNight
53%
720
20%
2516
20%
720
57%
720
25%
1501
December1st to 15thNight
47%
720
20%
2520
18%
720
52%
720
20%
1626
December16th to endNight
43%
768
18%
2688
18%
768
47%
768
19%
1785

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%313313346%58%
48057
Night
12%413323346%54%
47331
TransparencyDay
28%39%20%23%14%
47746
Night
29%410%19%22%14%
47143
SeeingDay
14%12%25%26%16%4
6117
Night
14%5%16%29%26%8%
15373

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
19%6%35%5%23445%39%
1569
16th to endDay
23%6%24323245%41%
1728
February1st to 15thDay
23%5%14424336%38%
1576
16th to endDay
23%6%243245%47%35%
1532
March1st to 15thDay
23%8%35%424446%31%
1980
16th to endDay
22%5%25%42435%8%35%
2112
April1st to 15thDay
19%5%25%5%2445%7%36%
2140
16th to endDay
10%423323349%50%
2173
May1st to 15thDay
7%21221235%9%60%
2331
16th to endDay
8%313313347%57%
2567
June1st to 15thDay
7%313213345%62%
2520
16th to endDay
31111225%77%
2520
July1st to 15thDay
11112484%
2450
16th to endDay
1111112483%
2468
August1st to 15thDay
1111112482%
2340
16th to endDay
11112485%
2336
September1st to 15thDay
11111113480%
2160
16th to endDay
412212236%73%
1966
October1st to 15thDay
11%212212335%62%
1705
16th to endDay
12%314323347%53%
1760
November1st to 15thDay
10%5%24425%447%46%
1705
16th to endDay
18%5%24423335%45%
1443
December1st to 15thDay
24%8%24323235%37%
1440
16th to endDay
26%8%2442335%6%33%
1536
January1st to 15thNight
18%5%245%245%5%7%37%
2366
16th to endNight
21%6%23313346%42%
2496
February1st to 15thNight
21%5%144345%5%5%36%
2276
16th to endNight
20%5%2442435%8%38%
1939
March1st to 15thNight
20%7%25%425%447%33%
1980
16th to endNight
19%5%2442345%7%41%
2112
April1st to 15thNight
14%5%25%5%35%45%6%41%
1808
16th to endNight
8%31332335%7%56%
1785
May1st to 15thNight
3213313348%64%
1619
16th to endNight
421231346%7%62%
1542
June1st to 15thNight
4312224347%62%
1440
16th to endNight
3211122479%
1440
July1st to 15thNight
11111385%
1507
16th to endNight
111226%80%
1701
August1st to 15thNight
11113483%
1620
16th to endNight
1111122482%
1866
September1st to 15thNight
111113482%
1800
16th to endNight
311212247%72%
1992
October1st to 15thNight
6%313313245%63%
2052
16th to endNight
10%41332345%7%54%
2112
November1st to 15thNight
13%4234246%6%8%43%
2154
16th to endNight
17%5%14423346%45%
2516
December1st to 15thNight
24%6%14423347%37%
2520
16th to endNight
24%6%24424336%35%
2688

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
45%411%16%11%10%
1569
16th to endDay
45%36%13%17%12%
1728
February1st to 15thDay
46%38%17%19%4
1576
16th to endDay
46%5%12%20%11%3
1532
March1st to 15thDay
53%5%9%13%14%4
1980
16th to endDay
46%5%12%18%13%2
2112
April1st to 15thDay
44%415%22%11%1
2140
16th to endDay
31%415%26%17%5%
2173
May1st to 15thDay
19%312%32%24%7%
2331
16th to endDay
24%5%13%32%20%4
2571
June1st to 15thDay
22%312%22%26%10%
2520
16th to endDay
11%15%17%39%23%
2520
July1st to 15thDay
6%1414%37%36%
2306
16th to endDay
9%1411%29%44%
2313
August1st to 15thDay
7%1323%33%30%
2324
16th to endDay
6%16%19%38%26%
2336
September1st to 15thDay
8%15%19%34%30%
2160
16th to endDay
14%27%27%29%19%
1966
October1st to 15thDay
25%36%22%25%17%
1705
16th to endDay
30%39%23%22%10%
1760
November1st to 15thDay
34%5%13%27%11%8%
1705
16th to endDay
41%410%18%18%6%
1443
December1st to 15thDay
49%47%16%17%3
1440
16th to endDay
51%39%15%13%6%
1536
January1st to 15thNight
42%5%12%16%13%9%
2366
16th to endNight
41%39%14%17%13%
2496
February1st to 15thNight
44%5%10%17%16%6%
2288
16th to endNight
41%5%13%22%13%3
1939
March1st to 15thNight
48%6%12%14%14%3
1980
16th to endNight
41%414%19%15%3
2112
April1st to 15thNight
40%6%15%20%14%2
1808
16th to endNight
25%412%30%20%5%
1785
May1st to 15thNight
19%310%26%30%9%
1620
16th to endNight
19%5%15%32%19%7%
1543
June1st to 15thNight
20%5%11%24%25%13%
1440
16th to endNight
11%16%17%36%26%
1440
July1st to 15thNight
5%1211%38%39%
1422
16th to endNight
7%2410%26%47%
1593
August1st to 15thNight
6%2417%31%37%
1611
16th to endNight
8%16%16%33%33%
1866
September1st to 15thNight
8%1415%33%36%
1800
16th to endNight
12%28%22%30%24%
1992
October1st to 15thNight
22%38%19%27%17%
2052
16th to endNight
28%48%23%23%12%
2112
November1st to 15thNight
34%5%16%22%13%7%
2154
16th to endNight
38%410%20%18%7%
2516
December1st to 15thNight
46%47%18%18%4
2520
16th to endNight
48%49%14%17%5%
2688

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
31%14%20%14%17%2
198
16th to endDay
26%12%22%19%16%3
256
February1st to 15thDay
27%11%24%18%17%
236
16th to endDay
25%22%20%21%9%1
227
March1st to 15thDay
32%17%24%15%6%4
270
16th to endDay
24%22%31%15%41
288
April1st to 15thDay
23%23%26%17%7%1
269
16th to endDay
21%24%27%18%5%2
270
May1st to 15thDay
11%23%34%19%8%2
288
16th to endDay
12%13%27%22%18%5%
330
June1st to 15thDay
10%14%34%28%9%1
315
16th to endDay
48%36%31%14%3
315
July1st to 15thDay
15%21%40%24%6%
305
16th to endDay
120%47%20%8%
327
August1st to 15thDay
2327%37%23%6%
315
16th to endDay
224%36%29%7%
332
September1st to 15thDay
35%21%40%21%8%
315
16th to endDay
5%9%22%30%23%8%
315
October1st to 15thDay
10%9%28%26%16%7%
278
16th to endDay
16%9%25%27%18%2
272
November1st to 15thDay
12%14%20%23%25%3
211
16th to endDay
18%16%31%18%8%8%
61
December1st to 15thDay
48%10%21%16%3
60
16th to endDay
28%12%9%23%17%9%
64
January1st to 15thNight
20%5%12%31%23%7%
720
16th to endNight
23%412%26%23%7%
768
February1st to 15thNight
23%5%15%27%21%5%
704
16th to endNight
23%6%22%25%17%4
632
March1st to 15thNight
23%8%16%27%19%4
720
16th to endNight
21%9%22%28%14%3
768
April1st to 15thNight
19%11%24%24%15%4
719
16th to endNight
11%12%24%26%18%5%
705
May1st to 15thNight
5%7%29%29%22%5%
540
16th to endNight
5%9%22%29%27%5%
421
June1st to 15thNight
5%9%27%31%24%1
360
16th to endNight
5%124%40%25%1
360
July1st to 15thNight
113%32%41%9%
402
16th to endNight
17%31%43%14%
564
August1st to 15thNight
18%34%40%14%
538
16th to endNight
19%30%48%9%
720
September1st to 15thNight
128%31%40%15%
720
16th to endNight
4411%31%34%12%
716
October1st to 15thNight
8%314%30%30%11%
684
16th to endNight
13%212%25%32%12%
704
November1st to 15thNight
15%416%29%26%8%
700
16th to endNight
20%6%12%27%22%10%
720
December1st to 15thNight
27%5%12%26%20%7%
720
16th to endNight
26%8%15%26%18%4
768
Page generated at 2017-10-07 11:07:45. Version ac04

Copyright 2017 A. Danko


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