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 2017-03-25.

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
43%
15231
24%
45324
15%
15185
52%
15185
31%
27120

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
33%
558
16%
2021
13%
558
40%
558
20%
1322
April1st to 15thNight
32%
494
26%
1647
13%
494
50%
494
31%
909
April16th to endNight
38%
495
21%
1650
13%
495
52%
495
28%
975
May1st to 15thNight
46%
495
20%
1592
16%
495
54%
495
28%
983
May16th to endNight
49%
515
19%
1406
15%
513
54%
513
30%
929
June1st to 15thNight
65%
495
25%
1320
18%
495
69%
495
44%
747
June16th to endNight
73%
495
25%
1320
19%
495
77%
495
46%
750
July1st to 15thNight
75%
465
19%
1300
18%
465
77%
465
40%
751
July16th to endNight
80%
522
22%
1468
23%
489
82%
489
43%
789
August1st to 15thNight
79%
494
26%
1513
31%
491
80%
491
42%
806
August16th to endNight
77%
525
22%
1750
26%
525
79%
525
35%
967
September1st to 15thNight
67%
495
27%
1650
30%
495
70%
495
32%
951
September16th to endNight
59%
566
29%
1792
22%
566
65%
566
34%
1030
October1st to 15thNight
54%
660
31%
1980
23%
660
60%
660
39%
1096
October16th to endNight
44%
704
32%
2112
19%
704
56%
704
37%
1178
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%42445%7%43%
45626
Night
12%5%24323447%49%
45517
TransparencyDay
38%5%12%24%15%3
45322
Night
34%411%26%19%3
45325
SeeingDay
13%5%20%27%23%10%
5016
Night
15%7%28%29%16%2
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
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%
2068
April1st to 15thDay
13%6%35%433336%46%
1971
16th to endDay
16%6%25%5%35%5%6%6%37%
1980
May1st to 15thDay
16%5%36%5%445%5%6%37%
2028
16th to endDay
12%6%35%6%36%5%5%8%37%
2355
June1st to 15thDay
8%425%5%35%5%6%8%44%
2310
16th to endDay
42235%45%6%8%9%46%
2310
July1st to 15thDay
9%425%5%37%6%8%9%36%
2241
16th to endDay
6%3245%46%5%7%11%42%
2284
August1st to 15thDay
8%425%4345%7%11%43%
2107
16th to endDay
7%4146%35%6%6%10%43%
2100
September1st to 15thDay
11%426%5%245%5%7%42%
1980
16th to endDay
13%41442345%6%48%
1825
October1st to 15thDay
12%5%15%433335%50%
1650
16th to endDay
13%413313445%54%
1760
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
18%7%34433346%39%
2021
April1st to 15thNight
10%323314437%53%
1647
16th to endNight
14%42432435%8%45%
1650
May1st to 15thNight
15%42442335%7%46%
1591
16th to endNight
11%6%27%5%23437%44%
1405
June1st to 15thNight
5%22332446%11%52%
1320
16th to endNight
4213325%45%10%55%
1320
July1st to 15thNight
4313325%5%7%10%50%
1386
16th to endNight
4213325%45%9%57%
1576
August1st to 15thNight
421342445%9%56%
1523
16th to endNight
6%3234345%6%8%51%
1750
September1st to 15thNight
10%31442445%7%49%
1650
16th to endNight
9%5%15%423447%52%
1792
October1st to 15thNight
11%41431235%7%54%
1980
16th to endNight
13%412322335%57%
2112
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
2070
April1st to 15thDay
39%49%24%18%2
1971
16th to endDay
45%5%12%21%13%1
1980
May1st to 15thDay
46%5%13%21%12%
2028
16th to endDay
43%8%14%21%9%2
2359
June1st to 15thDay
36%6%14%26%15%
2310
16th to endDay
30%7%16%27%15%2
2310
July1st to 15thDay
39%9%14%25%8%3
2098
16th to endDay
32%7%17%30%10%1
2129
August1st to 15thDay
32%7%13%28%14%2
2093
16th to endDay
34%7%15%21%14%6%
2100
September1st to 15thDay
38%6%11%20%16%6%
1980
16th to endDay
35%5%8%24%24%2
1825
October1st to 15thDay
36%37%24%22%5%
1650
16th to endDay
30%37%29%21%6%
1760
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%410%23%14%1
2021
April1st to 15thNight
31%411%25%21%4
1647
16th to endNight
36%412%28%15%3
1650
May1st to 15thNight
37%5%15%23%14%2
1592
16th to endNight
39%6%16%21%12%2
1407
June1st to 15thNight
24%6%16%30%20%1
1320
16th to endNight
24%5%15%30%19%4
1320
July1st to 15thNight
25%8%18%28%16%2
1300
16th to endNight
23%6%17%34%16%1
1468
August1st to 15thNight
23%6%14%32%20%1
1513
16th to endNight
27%7%16%24%17%5%
1750
September1st to 15thNight
32%6%9%25%19%7%
1650
16th to endNight
31%5%8%21%28%3
1792
October1st to 15thNight
29%39%25%24%7%
1980
16th to endNight
30%37%28%22%7%
2112
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
19%17%32%20%9%
103
April1st to 15thDay
14%15%33%26%9%1
210
16th to endDay
18%6%31%26%14%2
210
May1st to 15thDay
17%8%32%26%14%2
285
16th to endDay
16%426%29%16%6%
437
June1st to 15thDay
9%415%32%21%16%
420
16th to endDay
5%113%35%32%10%
420
July1st to 15thDay
9%311%33%31%10%
400
16th to endDay
7%6%22%39%23%
445
August1st to 15thDay
10%17%25%37%17%
380
16th to endDay
13%424%36%20%
268
September1st to 15thDay
9%37%27%35%16%
255
16th to endDay
14%116%25%24%17%
184
October1st to 15thDay
6%428%37%18%3
90
16th to endDay
17%323%36%16%2
96
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
21%9%31%28%8%
558
April1st to 15thNight
11%10%43%28%6%
494
16th to endNight
15%8%33%33%8%
495
May1st to 15thNight
15%329%36%13%
495
16th to endNight
15%323%34%19%3
515
June1st to 15thNight
6%219%36%30%3
495
16th to endNight
5%11%41%37%2
495
July1st to 15thNight
5%10%41%35%6%
465
16th to endNight
5%5%30%47%10%
522
August1st to 15thNight
5%6%34%45%8%
494
16th to endNight
8%8%36%41%5%
525
September1st to 15thNight
11%211%31%35%7%
495
16th to endNight
11%219%30%30%5%
566
October1st to 15thNight
13%323%31%23%4
660
16th to endNight
16%7%28%32%14%
704
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 2017-03-26 12:16:38. Version ac04

Copyright 2017 A. Danko


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