Lake Tawakoni State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Tawakoni State Park clear sky chart from 2005-11-05 to 2017-09-18.

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
50%
15580
28%
46916
20%
15534
58%
15534
37%
26173

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
35%
898
29%
2327
11%
895
46%
895
36%
1396
January16th to endNight
33%
960
31%
2496
11%
960
45%
960
36%
1517
February1st to 15thNight
31%
805
26%
2211
10%
800
42%
800
33%
1343
February16th to endNight
24%
581
30%
1843
10%
581
40%
581
29%
1047
March1st to 15thNight
33%
540
27%
1980
15%
540
49%
540
25%
1145
March16th to endNight
36%
576
24%
2112
16%
576
47%
576
28%
1175
April1st to 15thNight
33%
539
25%
1941
15%
539
50%
539
31%
1011
April16th to endNight
38%
540
25%
1767
18%
540
51%
540
32%
1002
May1st to 15thNight
38%
540
22%
1620
14%
540
51%
540
30%
979
May16th to endNight
56%
563
25%
1684
24%
561
63%
561
37%
953
June1st to 15thNight
75%
540
25%
1620
27%
540
79%
540
50%
804
June16th to endNight
75%
540
26%
1620
30%
540
77%
540
45%
853
July1st to 15thNight
77%
510
23%
1530
26%
510
80%
510
45%
804
July16th to endNight
87%
564
29%
1594
36%
531
90%
531
55%
767
August1st to 15thNight
89%
539
35%
1610
41%
536
89%
536
56%
761
August16th to endNight
76%
573
25%
1858
31%
573
77%
573
34%
1060
September1st to 15thNight
72%
540
23%
1980
28%
540
73%
540
36%
1027
September16th to endNight
74%
501
33%
1848
35%
501
78%
501
40%
898
October1st to 15thNight
61%
597
35%
1917
28%
597
67%
597
42%
979
October16th to endNight
52%
704
37%
2112
21%
704
63%
704
47%
1060
November1st to 15thNight
51%
700
32%
2100
20%
700
61%
700
42%
1128
November16th to endNight
40%
870
32%
2310
16%
870
51%
870
37%
1371
December1st to 15thNight
35%
900
28%
2340
12%
900
45%
900
33%
1498
December16th to endNight
35%
960
26%
2496
11%
960
44%
960
33%
1595

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%424424447%49%
47874
Night
10%413323347%55%
47114
TransparencyDay
34%5%11%22%20%6%
47574
Night
29%410%22%22%9%
46919
SeeingDay
10%317%28%29%10%
5588
Night
12%6%26%32%19%2
15582

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
14%5%23222235%54%
1611
16th to endDay
18%42331222452%
1728
February1st to 15thDay
18%6%3431322450%
1660
16th to endDay
19%5%23312225%50%
1631
March1st to 15thDay
19%6%24423326%45%
1980
16th to endDay
15%6%24423345%45%
2110
April1st to 15thDay
11%5%15%324446%47%
2007
16th to endDay
13%424425%448%46%
2190
May1st to 15thDay
13%5%36%5%35%445%42%
2331
16th to endDay
9%425%5%35%6%7%9%40%
2430
June1st to 15thDay
5%314425%5%6%8%51%
2340
16th to endDay
6%32342446%8%52%
2340
July1st to 15thDay
6%4235%35%5%6%10%45%
2340
16th to endDay
43245%35%6%7%11%46%
2466
August1st to 15thDay
411233346%9%59%
2340
16th to endDay
6%5%25%5%35%6%7%9%40%
2338
September1st to 15thDay
11%3243345%5%7%47%
1980
16th to endDay
8%313424446%56%
1837
October1st to 15thDay
12%313312345%56%
1702
16th to endDay
10%313212225%64%
1760
November1st to 15thDay
9%423424345%54%
1758
16th to endDay
14%41421322457%
1647
December1st to 15thDay
16%6%24424345%45%
1620
16th to endDay
18%7%23323335%47%
1728
January1st to 15thNight
14%423222236%56%
2327
16th to endNight
14%5%2331333455%
2496
February1st to 15thNight
13%5%1431333454%
2203
16th to endNight
14%413323236%53%
1843
March1st to 15thNight
17%5%23412335%49%
1980
16th to endNight
11%5%25%423436%51%
2112
April1st to 15thNight
8%31333346%7%54%
1941
16th to endNight
12%413314447%52%
1767
May1st to 15thNight
9%5%2442445%7%49%
1619
16th to endNight
7%3233245%6%10%50%
1683
June1st to 15thNight
4212313348%64%
1620
16th to endNight
431232435%9%58%
1620
July1st to 15thNight
5%31432445%11%53%
1620
16th to endNight
21122145%7%11%59%
1702
August1st to 15thNight
32211236%8%65%
1620
16th to endNight
5%315%5%35%6%6%10%47%
1858
September1st to 15thNight
10%32332345%7%54%
1980
16th to endNight
6%313323447%58%
1848
October1st to 15thNight
10%213322245%61%
1917
16th to endNight
11%21321121467%
2112
November1st to 15thNight
8%314313335%60%
2100
16th to endNight
13%42432223456%
2310
December1st to 15thNight
15%5%24323345%49%
2340
16th to endNight
15%7%23322345%48%
2496

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
33%36%21%26%7%
1612
16th to endDay
36%26%19%26%8%
1728
February1st to 15thDay
41%25%21%22%7%
1661
16th to endDay
38%25%20%22%9%
1631
March1st to 15thDay
41%37%18%21%7%
1980
16th to endDay
41%49%17%21%4
2112
April1st to 15thDay
36%5%9%21%16%9%
2007
16th to endDay
37%5%9%18%22%5%
2190
May1st to 15thDay
43%5%8%15%19%6%
2331
16th to endDay
39%8%14%20%15%2
2434
June1st to 15thDay
27%7%13%30%18%2
2340
16th to endDay
29%6%14%27%19%2
2340
July1st to 15thDay
30%7%17%29%13%
2201
16th to endDay
26%9%21%28%13%
2311
August1st to 15thDay
21%5%13%35%21%2
2326
16th to endDay
36%9%16%24%10%2
2338
September1st to 15thDay
34%6%12%22%17%7%
1980
16th to endDay
28%410%21%24%9%
1837
October1st to 15thDay
29%311%20%19%15%
1702
16th to endDay
24%26%20%30%14%
1760
November1st to 15thDay
32%28%24%22%8%
1758
16th to endDay
33%16%15%32%10%
1647
December1st to 15thDay
40%47%18%22%5%
1620
16th to endDay
40%27%23%18%6%
1728
January1st to 15thNight
32%37%18%26%11%
2327
16th to endNight
34%25%18%27%12%
2496
February1st to 15thNight
35%36%17%24%12%
2213
16th to endNight
33%38%19%21%12%
1843
March1st to 15thNight
38%38%17%21%10%
1980
16th to endNight
34%411%19%24%6%
2112
April1st to 15thNight
28%5%12%23%17%12%
1941
16th to endNight
31%5%10%19%23%8%
1767
May1st to 15thNight
34%6%10%19%20%8%
1620
16th to endNight
27%7%19%23%18%3
1685
June1st to 15thNight
19%5%13%34%22%4
1620
16th to endNight
22%5%12%28%24%5%
1620
July1st to 15thNight
23%5%16%34%17%2
1530
16th to endNight
15%6%20%37%18%2
1594
August1st to 15thNight
16%413%35%25%5%
1610
16th to endNight
29%7%14%29%14%3
1858
September1st to 15thNight
28%5%12%24%18%10%
1980
16th to endNight
24%49%21%27%11%
1848
October1st to 15thNight
25%38%23%21%17%
1917
16th to endNight
23%1418%29%21%
2112
November1st to 15thNight
26%38%23%25%11%
2100
16th to endNight
32%26%14%30%14%
2310
December1st to 15thNight
37%39%19%20%9%
2340
16th to endNight
38%28%19%21%8%
2496

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
14%10%40%27%7%
90
16th to endDay
17%8%40%25%7%1
96
February1st to 15thDay
14%7%45%27%4
90
16th to endDay
18%8%48%19%4
81
March1st to 15thDay
25%13%32%22%5%1
90
16th to endDay
13%9%39%22%12%2
96
April1st to 15thDay
13%11%30%27%15%
126
16th to endDay
18%7%34%24%13%1
300
May1st to 15thDay
17%10%30%27%11%2
468
16th to endDay
11%429%32%19%2
517
June1st to 15thDay
7%110%37%31%11%
495
16th to endDay
6%19%31%37%13%
495
July1st to 15thDay
419%34%37%13%
475
16th to endDay
31420%52%19%
515
August1st to 15thDay
4325%49%16%
493
16th to endDay
12%15%24%40%16%
378
September1st to 15thDay
2218%36%39%
135
16th to endDay
5%414%42%33%
96
October1st to 15thDay
210%40%36%11%
90
16th to endDay
13%411%34%29%7%
96
November1st to 15thDay
18%420%34%18%3
90
16th to endDay
25%7%28%25%8%3
90
December1st to 15thDay
31%223%26%10%6%
90
16th to endDay
16%12%43%21%5%
96
January1st to 15thNight
16%11%33%30%8%
900
16th to endNight
16%11%36%28%6%
960
February1st to 15thNight
16%10%37%30%5%
805
16th to endNight
18%12%42%23%3
581
March1st to 15thNight
18%11%32%30%7%
540
16th to endNight
13%8%38%30%8%
576
April1st to 15thNight
10%10%44%27%7%
539
16th to endNight
13%7%38%28%11%
540
May1st to 15thNight
11%5%39%30%11%1
540
16th to endNight
8%128%37%21%2
563
June1st to 15thNight
5%14%45%31%2
540
16th to endNight
4110%40%35%6%
540
July1st to 15thNight
5%18%40%39%5%
510
16th to endNight
3332%52%7%
564
August1st to 15thNight
5%232%51%7%
539
16th to endNight
6%333%46%8%
573
September1st to 15thNight
11%7%30%44%4
540
16th to endNight
8%110%30%43%5%
501
October1st to 15thNight
11%120%37%24%4
597
16th to endNight
11%5%28%31%20%2
704
November1st to 15thNight
9%6%29%36%17%1
700
16th to endNight
17%8%29%31%11%1
870
December1st to 15thNight
18%8%33%32%7%
900
16th to endNight
20%9%31%31%6%
960
Page generated at 2017-09-19 06:32:28. Version ac04

Copyright 2017 A. Danko


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