Lynch Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lynch Park clear sky chart from 2005-11-05 to

2017-09-12
.

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
31%
14868
17%
46759
8%
14836
41%
14836
19%
31002

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
16%
720
16%
2506
6%
716
29%
716
15%
1652
January16th to endNight
14%
768
17%
2688
4%
768
30%
768
13%
1772
February1st to 15thNight
15%
704
14%
2194
3%
701
29%
701
15%
1515
February16th to endNight
19%
631
21%
1893
6%
631
38%
631
19%
1263
March1st to 15thNight
20%
720
16%
2142
7%
720
31%
720
16%
1500
March16th to endNight
23%
768
21%
2051
6%
768
35%
768
21%
1400
April1st to 15thNight
28%
718
18%
1796
6%
718
35%
718
21%
1278
April16th to endNight
33%
574
17%
1654
6%
574
41%
574
20%
1134
May1st to 15thNight
32%
540
14%
1620
7%
540
38%
540
16%
1134
May16th to endNight
36%
433
11%
1555
9%
432
42%
432
14%
1047
June1st to 15thNight
39%
360
12%
1440
14%
360
44%
360
14%
980
June16th to endNight
50%
360
11%
1440
13%
360
55%
360
17%
886
July1st to 15thNight
56%
340
12%
1360
18%
340
57%
340
20%
822
July16th to endNight
54%
376
15%
1418
18%
354
61%
354
19%
901
August1st to 15thNight
56%
523
16%
1594
13%
521
58%
521
25%
1012
August16th to endNight
58%
697
20%
1843
12%
697
61%
697
30%
1189
September1st to 15thNight
54%
707
19%
1839
11%
707
57%
707
33%
1183
September16th to endNight
53%
657
26%
1815
17%
657
60%
657
33%
1097
October1st to 15thNight
36%
660
21%
1837
11%
660
44%
660
24%
1213
October16th to endNight
28%
704
15%
2288
7%
704
39%
704
19%
1498
November1st to 15thNight
29%
700
18%
2277
10%
700
40%
700
19%
1485
November16th to endNight
23%
720
18%
2340
7%
720
36%
720
17%
1525
December1st to 15thNight
18%
720
16%
2481
4%
720
33%
720
14%
1673
December16th to endNight
14%
768
16%
2688
4%
768
29%
768
12%
1843

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
16%5%2442445%7%40%
47909
Night
17%6%25%424446%40%
46929
Cloud CoverDay
16%6%2442445%7%41%
47919
Night
17%6%25%424446%40%
46934
TransparencyDay
41%6%13%21%14%2
47597
Night
44%6%12%21%14%1
46759
SeeingDay
18%12%21%30%14%2
5903
Night
17%19%24%25%10%1
14868

By Month

Percentage Cloud Cover NE (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
17%6%34423446%42%
1432
16th to endDay
16%6%25%5%13346%43%
1536
February1st to 15thDay
18%6%25%5%245%5%7%35%
1666
16th to endDay
14%7%35%4245%6%6%39%
1580
March1st to 15thDay
21%7%25%4235%5%7%35%
1807
16th to endDay
17%7%24423346%42%
2172
April1st to 15thDay
18%6%245%35%446%39%
2152
16th to endDay
18%423424446%42%
2304
May1st to 15thDay
24%7%36%423346%34%
2332
16th to endDay
16%5%24424348%41%
2568
June1st to 15thDay
24%5%2343445%7%34%
2520
16th to endDay
14%5%25%435%6%6%9%37%
2520
July1st to 15thDay
11%424435%5%7%9%40%
2520
16th to endDay
11%5%245%35%5%7%8%40%
2654
August1st to 15thDay
11%425%435%6%7%10%40%
2343
16th to endDay
11%413425%5%5%8%47%
2357
September1st to 15thDay
13%42442345%7%48%
2041
16th to endDay
13%413423346%52%
1815
October1st to 15thDay
20%5%24324336%42%
1793
16th to endDay
16%6%145%2345%5%42%
1584
November1st to 15thDay
21%7%24323335%42%
1581
16th to endDay
17%6%34333336%43%
1620
December1st to 15thDay
18%7%25%5%33336%39%
1476
16th to endDay
22%9%35%334436%34%
1536
January1st to 15thNight
16%8%25%424336%40%
2506
16th to endNight
17%9%35%5%24346%38%
2688
February1st to 15thNight
15%8%36%5%2445%6%36%
2193
16th to endNight
17%7%24423436%42%
1893
March1st to 15thNight
19%7%36%424445%38%
2129
16th to endNight
16%7%35%43434343%
2051
April1st to 15thNight
17%8%35%42445%5%37%
1796
16th to endNight
20%5%26%5%3434439%
1654
May1st to 15thNight
20%7%25%5%34445%35%
1620
16th to endNight
20%6%25%42345%7%35%
1553
June1st to 15thNight
25%6%25%5%13337%34%
1440
16th to endNight
15%5%25%42445%9%40%
1440
July1st to 15thNight
11%5%36%435%45%8%40%
1440
16th to endNight
12%5%25%5%36%6%6%8%37%
1514
August1st to 15thNight
9%425%6%35%6%5%8%42%
1604
16th to endNight
11%5%2442445%9%44%
1843
September1st to 15thNight
14%41442345%6%48%
1839
16th to endNight
13%413323346%52%
1815
October1st to 15thNight
19%5%15%423336%44%
1837
16th to endNight
19%6%14424446%41%
2288
November1st to 15thNight
17%5%24423346%43%
2277
16th to endNight
17%6%345%23346%41%
2340
December1st to 15thNight
19%6%35%42445%6%38%
2481
16th to endNight
19%9%25%423446%37%
2688

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
17%7%34313348%41%
1432
16th to endDay
16%6%25%42435%6%43%
1536
February1st to 15thDay
19%6%245%2445%8%35%
1666
16th to endDay
14%7%35%3245%5%6%40%
1580
March1st to 15thDay
20%7%25%43345%6%35%
1817
16th to endDay
17%6%25%324345%43%
2172
April1st to 15thDay
18%6%245%24447%40%
2152
16th to endDay
17%5%2332445%6%43%
2304
May1st to 15thDay
23%7%26%423346%34%
2332
16th to endDay
15%5%25%424448%40%
2568
June1st to 15thDay
23%5%343245%5%7%34%
2520
16th to endDay
14%4245%25%5%6%9%39%
2520
July1st to 15thDay
11%424425%5%7%9%41%
2520
16th to endDay
11%4245%25%5%7%9%41%
2654
August1st to 15thDay
10%4244346%7%9%42%
2343
16th to endDay
11%413325%5%5%8%48%
2357
September1st to 15thDay
12%5%2342335%7%49%
2041
16th to endDay
12%42332325%5%52%
1815
October1st to 15thDay
20%5%14323435%43%
1793
16th to endDay
17%6%14433346%43%
1584
November1st to 15thDay
22%7%23322345%42%
1581
16th to endDay
17%6%34323337%43%
1620
December1st to 15thDay
19%7%25%5%33326%39%
1476
16th to endDay
23%9%24334335%33%
1536
January1st to 15thNight
17%7%35%423346%40%
2506
16th to endNight
17%9%35%424346%38%
2688
February1st to 15thNight
15%8%36%5%245%46%36%
2186
16th to endNight
17%7%24423346%41%
1893
March1st to 15thNight
19%7%26%424445%38%
2142
16th to endNight
16%7%2443433443%
2050
April1st to 15thNight
17%7%35%42445%6%37%
1796
16th to endNight
20%436%5%24345%38%
1654
May1st to 15thNight
21%7%25%5%35%445%34%
1620
16th to endNight
20%6%26%42446%7%34%
1553
June1st to 15thNight
24%6%35%433337%34%
1440
16th to endNight
15%425%42446%8%40%
1440
July1st to 15thNight
10%5%36%5%35%46%8%40%
1440
16th to endNight
12%5%35%436%6%6%8%37%
1514
August1st to 15thNight
9%415%5%35%5%6%8%42%
1604
16th to endNight
12%5%1442435%8%45%
1843
September1st to 15thNight
14%424333446%48%
1839
16th to endNight
13%413323346%52%
1815
October1st to 15thNight
19%425%423345%44%
1837
16th to endNight
19%5%24423446%41%
2288
November1st to 15thNight
17%5%34423446%43%
2277
16th to endNight
17%6%24424346%41%
2340
December1st to 15thNight
20%6%25%42345%5%38%
2481
16th to endNight
19%9%2442435%7%36%
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
42%5%14%24%10%2
1433
16th to endDay
43%414%25%11%1
1536
February1st to 15thDay
46%7%13%20%10%
1669
16th to endDay
42%6%14%21%12%2
1580
March1st to 15thDay
48%6%13%18%11%2
1817
16th to endDay
42%411%21%14%5%
2172
April1st to 15thDay
43%6%11%19%16%3
2152
16th to endDay
40%6%10%22%16%3
2304
May1st to 15thDay
50%48%18%14%2
2332
16th to endDay
41%8%14%21%12%1
2572
June1st to 15thDay
48%7%13%19%10%1
2520
16th to endDay
39%10%14%19%14%1
2520
July1st to 15thDay
35%8%15%23%15%1
2371
16th to endDay
36%9%15%22%12%2
2487
August1st to 15thDay
34%10%16%25%12%1
2329
16th to endDay
31%8%12%27%18%1
2357
September1st to 15thDay
33%6%14%22%21%1
2041
16th to endDay
33%410%25%23%2
1815
October1st to 15thDay
41%5%10%23%15%2
1793
16th to endDay
41%5%12%24%14%2
1584
November1st to 15thDay
45%412%21%13%1
1581
16th to endDay
42%5%14%21%14%1
1620
December1st to 15thDay
47%416%15%15%
1476
16th to endDay
53%5%13%17%9%
1536
January1st to 15thNight
45%6%14%20%10%1
2506
16th to endNight
47%5%11%20%13%1
2688
February1st to 15thNight
48%6%13%20%10%1
2194
16th to endNight
43%5%12%22%13%2
1893
March1st to 15thNight
47%6%10%19%13%2
2142
16th to endNight
44%49%17%18%4
2051
April1st to 15thNight
46%5%9%18%17%2
1796
16th to endNight
48%49%18%16%3
1654
May1st to 15thNight
50%5%11%15%14%2
1620
16th to endNight
47%7%14%17%11%1
1555
June1st to 15thNight
51%6%11%19%10%
1440
16th to endNight
39%8%12%20%15%1
1440
July1st to 15thNight
38%8%13%25%14%
1360
16th to endNight
40%9%13%24%9%2
1418
August1st to 15thNight
37%8%13%23%14%2
1594
16th to endNight
35%7%11%25%19%
1843
September1st to 15thNight
35%6%13%24%19%1
1839
16th to endNight
32%5%7%26%26%1
1815
October1st to 15thNight
42%5%11%22%15%3
1837
16th to endNight
43%6%13%22%12%
2288
November1st to 15thNight
42%7%12%20%14%2
2277
16th to endNight
44%5%13%22%12%2
2340
December1st to 15thNight
46%7%14%20%10%
2481
16th to endNight
49%6%12%20%10%
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
16%16%25%38%3
60
16th to endDay
21%14%37%26%
64
February1st to 15thDay
24%18%33%21%2
237
16th to endDay
12%17%38%25%5%
239
March1st to 15thDay
21%21%31%21%4
270
16th to endDay
20%18%32%21%6%
288
April1st to 15thDay
21%15%26%26%10%
270
16th to endDay
18%15%22%32%9%2
270
May1st to 15thDay
27%12%23%21%11%2
288
16th to endDay
19%11%15%38%14%
331
June1st to 15thDay
21%11%15%35%14%
315
16th to endDay
13%11%17%41%13%2
315
July1st to 15thDay
17%7%8%39%24%3
305
16th to endDay
12%10%9%38%26%2
326
August1st to 15thDay
12%6%15%34%27%4
313
16th to endDay
12%5%9%37%24%10%
332
September1st to 15thDay
15%5%18%31%22%6%
299
16th to endDay
19%6%13%31%15%13%
254
October1st to 15thDay
24%8%21%24%16%5%
252
16th to endDay
20%11%31%27%9%
240
November1st to 15thDay
23%15%20%26%11%1
235
16th to endDay
21%23%26%17%10%1
240
December1st to 15thDay
23%11%37%20%6%
96
16th to endDay
28%9%37%23%1
64
January1st to 15thNight
18%27%34%17%2
720
16th to endNight
19%27%34%15%2
768
February1st to 15thNight
17%26%34%18%2
704
16th to endNight
21%24%32%17%4
631
March1st to 15thNight
22%22%30%20%3
720
16th to endNight
18%21%32%19%8%
768
April1st to 15thNight
17%21%28%25%7%
718
16th to endNight
16%19%24%28%10%
574
May1st to 15thNight
18%18%22%27%10%2
540
16th to endNight
21%18%17%30%11%
433
June1st to 15thNight
20%18%13%30%14%2
360
16th to endNight
15%17%9%43%14%
360
July1st to 15thNight
8%13%10%45%18%3
340
16th to endNight
13%16%7%40%21%1
376
August1st to 15thNight
9%10%13%42%23%1
523
16th to endNight
13%9%9%33%29%4
697
September1st to 15thNight
13%9%16%36%21%2
707
16th to endNight
16%10%14%28%22%6%
657
October1st to 15thNight
20%13%21%29%12%2
660
16th to endNight
20%15%31%23%7%
704
November1st to 15thNight
17%20%27%24%9%1
700
16th to endNight
17%26%28%19%7%1
720
December1st to 15thNight
20%25%29%19%4
720
16th to endNight
22%28%32%15%1
768
Page generated at 2017-09-13 07:39:12. Version ac04

Copyright 2017 A. Danko


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