Palmer Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Palmer Lake 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
34%
15874
22%
47097
12%
15827
44%
15827
26%
29480

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
15%
900
21%
2438
5%
895
28%
895
19%
1641
January16th to endNight
15%
960
21%
2496
5%
960
27%
960
22%
1699
February1st to 15thNight
15%
842
17%
2250
3%
839
24%
839
19%
1555
February16th to endNight
16%
631
21%
1893
5%
631
29%
631
20%
1217
March1st to 15thNight
16%
624
18%
2064
7%
624
27%
624
17%
1380
March16th to endNight
20%
576
15%
2052
7%
576
32%
576
17%
1381
April1st to 15thNight
25%
539
22%
1797
10%
539
42%
539
24%
1050
April16th to endNight
28%
540
20%
1800
12%
540
43%
540
24%
1136
May1st to 15thNight
35%
540
17%
1703
11%
539
44%
539
25%
1090
May16th to endNight
39%
563
19%
1497
12%
561
45%
561
26%
1037
June1st to 15thNight
57%
540
21%
1440
14%
540
63%
540
41%
848
June16th to endNight
57%
540
24%
1440
14%
540
64%
540
43%
828
July1st to 15thNight
64%
510
19%
1360
14%
510
66%
510
40%
812
July16th to endNight
71%
564
22%
1550
19%
531
76%
531
39%
892
August1st to 15thNight
72%
539
23%
1670
26%
536
74%
536
39%
907
August16th to endNight
67%
573
25%
1910
27%
573
72%
573
35%
1047
September1st to 15thNight
61%
540
27%
1800
26%
540
66%
540
30%
1048
September16th to endNight
57%
646
31%
1933
23%
646
65%
646
34%
1115
October1st to 15thNight
45%
684
29%
2052
20%
684
53%
684
35%
1170
October16th to endNight
29%
704
27%
2112
13%
704
43%
704
30%
1240
November1st to 15thNight
32%
700
29%
2253
15%
700
48%
700
31%
1243
November16th to endNight
22%
759
23%
2379
11%
759
35%
759
22%
1498
December1st to 15thNight
18%
900
18%
2520
5%
900
30%
900
20%
1740
December16th to endNight
15%
960
19%
2688
4%
960
28%
960
17%
1906

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
12%6%25%5%35%45%7%41%
48095
Night
12%6%25%424446%46%
47284
TransparencyDay
40%6%11%23%15%2
47785
Night
38%5%11%24%17%2
47099
SeeingDay
15%10%27%25%16%4
5905
Night
16%13%31%24%12%1
15874

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
13%8%36%425%345%42%
1498
16th to endDay
10%6%46%5%23446%43%
1728
February1st to 15thDay
13%9%47%434445%37%
1612
16th to endDay
12%9%35%4345%5%6%38%
1580
March1st to 15thDay
14%9%36%5%24435%38%
1905
16th to endDay
17%11%36%5%34446%31%
2170
April1st to 15thDay
12%6%2443445%6%45%
2151
16th to endDay
19%7%36%5%33447%35%
2160
May1st to 15thDay
17%5%244345%6%8%36%
2241
16th to endDay
12%6%35%6%35%45%7%38%
2617
June1st to 15thDay
8%425%6%35%5%6%8%43%
2520
16th to endDay
6%3135%35%6%7%10%46%
2520
July1st to 15thDay
10%425%5%36%5%6%9%40%
2520
16th to endDay
5%414447%7%8%11%40%
2508
August1st to 15thDay
9%425%5%36%5%7%9%40%
2279
16th to endDay
9%4245%35%6%7%9%40%
2292
September1st to 15thDay
13%5%1343445%8%45%
2160
16th to endDay
10%4244245%5%7%47%
2010
October1st to 15thDay
12%6%24334336%49%
1706
16th to endDay
12%5%13322345%54%
1760
November1st to 15thDay
11%6%24314436%53%
1604
16th to endDay
15%9%24424345%42%
1578
December1st to 15thDay
16%8%45%5%36%246%36%
1440
16th to endDay
14%10%5%6%5%23446%35%
1536
January1st to 15thNight
13%7%35%5%34345%42%
2438
16th to endNight
10%7%5%6%6%24445%41%
2496
February1st to 15thNight
14%9%48%423445%38%
2241
16th to endNight
11%9%46%5%23335%44%
1893
March1st to 15thNight
16%10%26%42334440%
2064
16th to endNight
17%8%36%42435%5%36%
2052
April1st to 15thNight
11%5%24424447%48%
1797
16th to endNight
14%6%245%24346%44%
1800
May1st to 15thNight
16%42443445%6%44%
1703
16th to endNight
10%6%25%6%35%5%47%41%
1496
June1st to 15thNight
7%213425%45%10%51%
1440
16th to endNight
5%314225%46%10%53%
1440
July1st to 15thNight
9%21342435%9%52%
1440
16th to endNight
43145%25%46%10%51%
1657
August1st to 15thNight
5%3133235%6%10%53%
1680
16th to endNight
5%31442447%9%51%
1910
September1st to 15thNight
11%424324446%50%
1800
16th to endNight
9%42431445%6%53%
1933
October1st to 15thNight
10%324423346%55%
2052
16th to endNight
16%41331324453%
2112
November1st to 15thNight
10%423423345%55%
2253
16th to endNight
17%8%24313335%45%
2379
December1st to 15thNight
18%8%35%424347%36%
2520
16th to endNight
15%10%36%5%24445%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
43%410%23%16%2
1499
16th to endDay
40%414%27%11%1
1728
February1st to 15thDay
48%411%22%11%1
1614
16th to endDay
45%5%10%24%11%2
1580
March1st to 15thDay
47%5%9%20%14%3
1905
16th to endDay
52%6%12%18%9%
2172
April1st to 15thDay
39%5%11%22%19%2
2151
16th to endDay
49%5%10%21%12%1
2160
May1st to 15thDay
45%6%12%22%12%
2241
16th to endDay
44%8%12%18%13%2
2621
June1st to 15thDay
36%7%13%25%16%1
2520
16th to endDay
29%7%17%25%16%3
2520
July1st to 15thDay
38%7%11%24%14%4
2371
16th to endDay
33%10%15%25%13%1
2352
August1st to 15thDay
37%9%12%24%15%1
2265
16th to endDay
37%8%12%21%14%5%
2292
September1st to 15thDay
36%6%9%24%19%3
2160
16th to endDay
35%6%8%28%19%2
2010
October1st to 15thDay
37%47%24%21%3
1706
16th to endDay
32%38%28%22%4
1760
November1st to 15thDay
33%310%24%18%8%
1604
16th to endDay
43%39%24%17%1
1578
December1st to 15thDay
50%49%21%12%1
1440
16th to endDay
49%5%10%19%12%2
1536
January1st to 15thNight
42%5%9%22%16%2
2438
16th to endNight
43%411%23%15%1
2496
February1st to 15thNight
46%410%22%13%2
2250
16th to endNight
43%312%23%15%1
1893
March1st to 15thNight
47%49%19%16%2
2064
16th to endNight
48%5%11%22%10%
2052
April1st to 15thNight
34%6%12%26%17%2
1797
16th to endNight
40%5%9%26%16%1
1800
May1st to 15thNight
39%6%15%20%16%1
1704
16th to endNight
41%8%10%20%14%3
1498
June1st to 15thNight
26%7%15%30%19%1
1440
16th to endNight
24%7%15%27%20%4
1440
July1st to 15thNight
29%5%15%29%16%4
1360
16th to endNight
26%8%16%30%17%1
1550
August1st to 15thNight
23%8%15%29%20%1
1670
16th to endNight
27%7%13%24%21%5%
1910
September1st to 15thNight
34%5%7%25%21%5%
1800
16th to endNight
30%6%8%26%25%3
1933
October1st to 15thNight
31%49%25%24%5%
2052
16th to endNight
35%38%26%20%5%
2112
November1st to 15thNight
30%410%24%21%7%
2253
16th to endNight
41%38%24%20%1
2379
December1st to 15thNight
47%411%20%14%1
2520
16th to endNight
48%5%10%18%12%3
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
33%25%36%31
90
16th to endDay
19%37%34%6%2
96
February1st to 15thDay
24%26%38%10%
90
16th to endDay
29%20%37%11%1
81
March1st to 15thDay
26%25%42%41
90
16th to endDay
26%23%37%10%1
156
April1st to 15thDay
19%16%37%20%5%
270
16th to endDay
23%16%34%15%7%2
270
May1st to 15thDay
17%19%33%19%7%2
330
16th to endDay
16%11%35%21%11%3
517
June1st to 15thDay
10%5%27%33%17%5%
495
16th to endDay
7%7%31%34%15%3
495
July1st to 15thDay
12%322%34%21%5%
475
16th to endDay
6%117%33%33%7%
515
August1st to 15thDay
12%113%32%29%9%
432
16th to endDay
12%217%29%26%11%
332
September1st to 15thDay
13%6%15%27%28%9%
315
16th to endDay
12%420%27%25%9%
287
October1st to 15thDay
14%11%36%28%7%
107
16th to endDay
15%13%38%27%5%
96
November1st to 15thDay
14%437%27%10%5%
90
16th to endDay
40%18%24%12%4
90
December1st to 15thDay
25%21%31%15%24
90
16th to endDay
30%28%32%8%1
96
January1st to 15thNight
23%25%33%14%3
900
16th to endNight
16%25%38%15%2
960
February1st to 15thNight
21%23%38%16%1
842
16th to endNight
19%22%40%16%1
631
March1st to 15thNight
25%19%36%16%2
624
16th to endNight
21%15%38%19%4
576
April1st to 15thNight
16%19%37%22%4
539
16th to endNight
17%13%37%24%7%
540
May1st to 15thNight
18%8%34%26%10%
540
16th to endNight
12%7%33%30%13%2
563
June1st to 15thNight
9%224%37%23%2
540
16th to endNight
6%228%38%21%2
540
July1st to 15thNight
11%117%39%25%5%
510
16th to endNight
5%111%44%29%6%
564
August1st to 15thNight
7%111%34%39%4
539
16th to endNight
5%17%36%33%6%
573
September1st to 15thNight
12%316%32%29%5%
540
16th to endNight
12%5%19%27%29%5%
646
October1st to 15thNight
12%7%30%26%19%3
684
16th to endNight
20%13%34%23%7%
704
November1st to 15thNight
12%15%36%25%9%1
700
16th to endNight
24%19%31%20%4
759
December1st to 15thNight
26%16%36%16%3
900
16th to endNight
24%20%37%15%1
960
Page generated at 2017-10-07 13:07:48. Version ac04

Copyright 2017 A. Danko


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