West Plains
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the West Plains clear sky chart from 2005-11-05 to 2017-10-31.

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
44%
15923
24%
47439
15%
15877
53%
15877
32%
28279

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
23%
900
26%
2351
7%
895
37%
895
29%
1490
January16th to endNight
22%
960
27%
2496
7%
960
35%
960
33%
1545
February1st to 15thNight
23%
861
21%
2270
6%
858
32%
858
29%
1462
February16th to endNight
22%
631
24%
1893
6%
631
37%
631
29%
1115
March1st to 15thNight
27%
570
20%
2010
12%
570
37%
570
20%
1272
March16th to endNight
32%
576
15%
2085
13%
576
39%
576
20%
1374
April1st to 15thNight
33%
539
24%
1797
12%
539
50%
539
31%
995
April16th to endNight
38%
540
21%
1800
13%
540
50%
540
27%
1084
May1st to 15thNight
47%
540
19%
1736
15%
540
54%
540
29%
1055
May16th to endNight
50%
563
20%
1537
15%
561
56%
561
31%
996
June1st to 15thNight
67%
540
24%
1440
18%
540
71%
540
46%
803
June16th to endNight
72%
540
27%
1440
21%
540
76%
540
46%
813
July1st to 15thNight
76%
510
18%
1426
17%
510
77%
510
41%
819
July16th to endNight
80%
564
24%
1594
25%
531
83%
531
44%
849
August1st to 15thNight
78%
539
24%
1652
29%
536
78%
536
40%
908
August16th to endNight
77%
573
23%
1910
28%
573
79%
573
35%
1057
September1st to 15thNight
67%
540
27%
1800
29%
540
71%
540
34%
1014
September16th to endNight
61%
618
31%
1955
25%
618
67%
618
35%
1103
October1st to 15thNight
54%
720
30%
2160
22%
720
60%
720
38%
1200
October16th to endNight
44%
768
34%
2304
20%
768
57%
768
38%
1272
November1st to 15thNight
42%
700
31%
2184
18%
700
55%
700
37%
1174
November16th to endNight
32%
771
26%
2391
15%
771
43%
771
28%
1451
December1st to 15thNight
29%
900
20%
2520
9%
900
39%
900
27%
1642
December16th to endNight
26%
960
22%
2688
8%
960
37%
960
24%
1786

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%5%25%43445%7%43%
48304
Night
12%5%24323447%49%
47632
TransparencyDay
38%5%12%24%16%3
48000
Night
34%411%26%19%3
47440
SeeingDay
13%5%19%27%23%9%
5937
Night
15%7%28%29%16%2
15923

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
17%414314245%50%
1584
16th to endDay
14%5%25%323336%48%
1728
February1st to 15thDay
14%6%35%5%2335%6%42%
1590
16th to endDay
14%8%35%5%33446%41%
1580
March1st to 15thDay
16%6%25%423346%43%
1959
16th to endDay
19%6%35%5%2445%6%36%
2137
April1st to 15thDay
12%6%35%433346%46%
2151
16th to endDay
18%6%25%5%35%5%5%6%36%
2160
May1st to 15thDay
16%426%5%3445%6%38%
2213
16th to endDay
11%5%25%6%36%5%5%9%37%
2576
June1st to 15thDay
7%425%5%35%5%5%8%44%
2520
16th to endDay
5%3235%45%6%8%9%46%
2520
July1st to 15thDay
9%425%5%37%6%7%9%37%
2445
16th to endDay
6%324446%5%7%11%44%
2466
August1st to 15thDay
10%425%4345%7%10%41%
2298
16th to endDay
7%415%6%36%6%6%9%42%
2292
September1st to 15thDay
11%426%5%245%5%7%45%
2160
16th to endDay
12%42443345%6%48%
1990
October1st to 15thDay
12%5%15%433335%49%
1800
16th to endDay
12%413313445%54%
1919
November1st to 15thDay
11%423423345%54%
1674
16th to endDay
18%5%25%312325%46%
1566
December1st to 15thDay
19%5%24423446%42%
1440
16th to endDay
19%7%34224346%40%
1536
January1st to 15thNight
16%5%23323346%48%
2351
16th to endNight
12%6%24323345%51%
2496
February1st to 15thNight
13%7%34423346%47%
2261
16th to endNight
13%6%13324447%48%
1893
March1st to 15thNight
18%5%25%423445%43%
2010
16th to endNight
17%7%3443435%6%38%
2085
April1st to 15thNight
10%324314438%52%
1797
16th to endNight
15%42432435%8%44%
1800
May1st to 15thNight
15%42432335%7%48%
1735
16th to endNight
11%5%27%433438%45%
1536
June1st to 15thNight
5%22332345%12%54%
1440
16th to endNight
5%21332445%10%55%
1440
July1st to 15thNight
5%3133245%7%10%51%
1512
16th to endNight
4213315%45%8%57%
1702
August1st to 15thNight
431442445%9%54%
1662
16th to endNight
5%3234345%6%9%50%
1910
September1st to 15thNight
9%31442445%7%51%
1800
16th to endNight
8%415%323447%53%
1955
October1st to 15thNight
11%41431245%7%54%
2160
16th to endNight
12%412313335%58%
2304
November1st to 15thNight
10%422223346%56%
2184
16th to endNight
17%6%23312335%48%
2391
December1st to 15thNight
20%5%24323347%42%
2520
16th to endNight
19%7%24423346%41%
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
37%39%27%17%4
1585
16th to endDay
37%312%27%15%3
1728
February1st to 15thDay
43%312%25%14%1
1591
16th to endDay
43%310%24%14%2
1580
March1st to 15thDay
42%310%22%15%4
1959
16th to endDay
48%412%21%11%1
2139
April1st to 15thDay
40%410%24%18%2
2151
16th to endDay
46%5%11%20%13%2
2160
May1st to 15thDay
45%5%12%22%13%
2213
16th to endDay
42%8%14%21%10%2
2580
June1st to 15thDay
35%6%14%25%17%
2520
16th to endDay
30%6%16%27%16%2
2520
July1st to 15thDay
38%9%13%24%10%3
2302
16th to endDay
31%6%16%31%11%1
2311
August1st to 15thDay
35%7%13%27%14%1
2284
16th to endDay
35%7%14%21%14%5%
2292
September1st to 15thDay
36%6%10%22%16%6%
2160
16th to endDay
35%5%8%25%23%2
1990
October1st to 15thDay
37%38%23%22%4
1800
16th to endDay
30%47%28%22%6%
1919
November1st to 15thDay
32%48%24%22%7%
1674
16th to endDay
41%28%23%22%2
1566
December1st to 15thDay
43%411%23%15%2
1440
16th to endDay
44%411%21%14%3
1536
January1st to 15thNight
37%39%26%21%2
2351
16th to endNight
35%210%31%17%2
2496
February1st to 15thNight
39%39%27%17%2
2270
16th to endNight
35%314%24%18%3
1893
March1st to 15thNight
43%5%9%21%15%5%
2010
16th to endNight
46%5%10%22%13%1
2085
April1st to 15thNight
31%412%25%20%4
1797
16th to endNight
37%412%27%14%3
1800
May1st to 15thNight
37%5%14%22%17%2
1736
16th to endNight
38%5%17%22%13%2
1538
June1st to 15thNight
23%5%16%29%22%1
1440
16th to endNight
24%5%14%29%20%5%
1440
July1st to 15thNight
25%8%17%27%18%2
1426
16th to endNight
22%6%16%34%18%1
1594
August1st to 15thNight
25%7%14%31%19%1
1652
16th to endNight
27%7%16%23%17%6%
1910
September1st to 15thNight
31%5%8%28%19%6%
1800
16th to endNight
30%5%9%22%28%3
1955
October1st to 15thNight
29%410%24%24%6%
2160
16th to endNight
29%37%27%23%8%
2304
November1st to 15thNight
29%28%27%23%8%
2184
16th to endNight
39%26%25%22%3
2391
December1st to 15thNight
42%311%23%16%2
2520
16th to endNight
44%310%22%15%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
30%7%44%15%2
90
16th to endDay
14%22%42%13%6%
96
February1st to 15thDay
8%21%50%15%31
90
16th to endDay
16%18%35%25%3
81
March1st to 15thDay
26%14%32%21%5%
90
16th to endDay
17%17%33%22%8%
123
April1st to 15thDay
12%15%31%28%10%1
270
16th to endDay
22%8%30%22%14%2
270
May1st to 15thDay
17%8%30%25%15%2
350
16th to endDay
15%6%27%30%15%5%
517
June1st to 15thDay
8%414%33%24%15%
495
16th to endDay
7%115%37%29%9%
495
July1st to 15thDay
10%210%32%33%10%
475
16th to endDay
6%6%21%40%24%
515
August1st to 15thDay
14%18%25%34%15%
451
16th to endDay
11%15%29%35%17%
332
September1st to 15thDay
9%38%26%35%16%
315
16th to endDay
12%115%27%27%15%
237
October1st to 15thDay
11%7%23%35%18%2
135
16th to endDay
13%9%29%34%13%1
144
November1st to 15thDay
10%430%26%21%7%
90
16th to endDay
34%12%30%14%8%
90
December1st to 15thDay
16%14%38%18%5%5%
90
16th to endDay
25%12%40%20%1
96
January1st to 15thNight
21%15%37%21%4
900
16th to endNight
16%13%44%22%3
960
February1st to 15thNight
18%12%42%24%2
861
16th to endNight
17%12%44%22%3
631
March1st to 15thNight
21%12%34%28%2
570
16th to endNight
20%9%32%28%7%
576
April1st to 15thNight
11%10%42%29%6%
539
16th to endNight
16%8%33%32%9%
540
May1st to 15thNight
16%329%35%14%1
540
16th to endNight
14%324%36%18%2
563
June1st to 15thNight
6%218%37%31%3
540
16th to endNight
6%12%42%34%2
540
July1st to 15thNight
6%10%39%38%5%
510
16th to endNight
45%29%48%10%
564
August1st to 15thNight
5%6%34%44%8%
539
16th to endNight
7%8%37%40%5%
573
September1st to 15thNight
11%211%30%37%6%
540
16th to endNight
10%219%30%32%5%
618
October1st to 15thNight
13%323%31%23%3
720
16th to endNight
15%7%30%31%14%1
768
November1st to 15thNight
12%9%31%30%14%
700
16th to endNight
22%8%32%23%11%
771
December1st to 15thNight
25%8%32%26%6%
900
16th to endNight
24%10%35%25%4
960
Page generated at 2017-11-01 16:23:35. Version ac04

Copyright 2017 A. Danko


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