Battleship Texas State Historic Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Battleship Texas State Historic Site clear sky chart from 2005-11-05 to 2017-09-20.

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
58%
15371
23%
46936
19%
15326
62%
15326
31%
28351

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
40%
899
22%
2327
11%
895
45%
895
28%
1561
January16th to endNight
39%
960
24%
2496
11%
960
45%
960
29%
1659
February1st to 15thNight
40%
791
23%
2199
12%
787
46%
787
28%
1416
February16th to endNight
34%
503
25%
1765
15%
503
44%
503
23%
1089
March1st to 15thNight
39%
540
24%
1980
17%
540
49%
540
22%
1225
March16th to endNight
51%
576
22%
2112
20%
576
57%
576
28%
1192
April1st to 15thNight
47%
539
21%
1930
18%
539
55%
539
25%
1164
April16th to endNight
47%
540
21%
1800
19%
540
53%
540
24%
1127
May1st to 15thNight
54%
539
19%
1739
19%
539
58%
539
27%
1069
May16th to endNight
67%
562
23%
1685
25%
561
70%
561
34%
982
June1st to 15thNight
84%
540
19%
1620
23%
540
85%
540
47%
829
June16th to endNight
75%
540
16%
1620
20%
540
75%
540
31%
998
July1st to 15thNight
80%
510
17%
1530
21%
510
80%
510
35%
893
July16th to endNight
84%
564
19%
1594
23%
531
85%
531
34%
953
August1st to 15thNight
90%
539
26%
1628
30%
536
90%
536
54%
787
August16th to endNight
75%
573
15%
1910
17%
573
75%
573
26%
1198
September1st to 15thNight
75%
540
16%
1978
19%
540
76%
540
27%
1149
September16th to endNight
73%
507
26%
1870
30%
507
73%
507
28%
1063
October1st to 15thNight
77%
616
31%
1936
29%
616
78%
616
44%
995
October16th to endNight
66%
704
35%
2112
27%
704
70%
704
45%
1117
November1st to 15thNight
64%
700
28%
2100
23%
700
66%
700
35%
1235
November16th to endNight
54%
729
33%
2169
23%
729
61%
729
36%
1254
December1st to 15thNight
45%
900
23%
2340
14%
900
49%
900
26%
1622
December16th to endNight
38%
960
19%
2496
10%
960
42%
960
24%
1774

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%35%5%35%5%6%8%37%
47897
Night
11%5%2442345%8%47%
47131
TransparencyDay
41%8%12%17%14%6%
47597
Night
34%6%14%20%16%8%
46936
SeeingDay
10%213%25%29%17%
5384
Night
13%317%32%28%4
15374

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
18%5%345%2444441%
1611
16th to endDay
19%6%25%323335%43%
1728
February1st to 15thDay
19%7%35%424245%40%
1672
16th to endDay
21%6%24424435%39%
1709
March1st to 15thDay
22%6%35%324335%37%
1980
16th to endDay
13%7%35%5%24447%41%
2110
April1st to 15thDay
15%6%36%425%446%40%
2016
16th to endDay
13%6%36%6%345%5%7%38%
2160
May1st to 15thDay
11%5%37%6%35%5%6%8%35%
2208
16th to endDay
7%6%26%6%46%5%7%10%34%
2430
June1st to 15thDay
5%426%6%38%7%7%9%37%
2340
16th to endDay
6%436%8%5%10%7%8%10%27%
2340
July1st to 15thDay
9%425%6%47%8%8%13%28%
2340
16th to endDay
6%5%36%7%5%8%7%9%11%27%
2466
August1st to 15thDay
33247%47%8%10%11%36%
2322
16th to endDay
9%437%7%47%7%8%9%30%
2290
September1st to 15thDay
9%5%25%6%47%7%8%9%33%
1980
16th to endDay
10%5%36%5%445%7%6%39%
1859
October1st to 15thDay
9%33442445%7%50%
1682
16th to endDay
10%313423435%57%
1760
November1st to 15thDay
9%425%5%35%46%6%45%
1758
16th to endDay
13%6%25%434235%48%
1788
December1st to 15thDay
16%7%36%5%3435%7%35%
1620
16th to endDay
17%8%36%5%3445%5%35%
1728
January1st to 15thNight
19%6%24323345%43%
2327
16th to endNight
18%6%35%322345%44%
2496
February1st to 15thNight
17%6%24423346%44%
2189
16th to endNight
17%8%24422245%44%
1765
March1st to 15thNight
20%6%24323347%41%
1980
16th to endNight
10%5%24433347%49%
2112
April1st to 15thNight
13%5%35%42346%8%42%
1930
16th to endNight
16%6%245%2445%7%42%
1800
May1st to 15thNight
9%5%245%345%7%9%41%
1738
16th to endNight
5%414435%5%6%10%47%
1683
June1st to 15thNight
321332347%12%55%
1620
16th to endNight
6%4245%25%5%9%12%42%
1620
July1st to 15thNight
5%323325%45%12%49%
1620
16th to endNight
3324326%6%6%11%49%
1702
August1st to 15thNight
21122346%13%61%
1638
16th to endNight
7%3145%35%5%8%12%40%
1910
September1st to 15thNight
7%424425%5%6%11%45%
1978
16th to endNight
8%5%2442346%8%48%
1870
October1st to 15thNight
6%21331346%6%60%
1936
16th to endNight
9%313312235%63%
2112
November1st to 15thNight
9%42343335%6%52%
2100
16th to endNight
12%42432333455%
2169
December1st to 15thNight
16%6%26%5%34346%40%
2340
16th to endNight
18%8%35%5%23335%38%
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
45%36%13%20%10%
1612
16th to endDay
44%36%16%17%12%
1728
February1st to 15thDay
46%45%16%17%10%
1673
16th to endDay
46%5%7%13%17%9%
1709
March1st to 15thDay
48%5%8%13%18%6%
1980
16th to endDay
41%6%9%14%21%5%
2112
April1st to 15thDay
43%5%9%16%15%8%
2016
16th to endDay
42%7%10%16%15%7%
2160
May1st to 15thDay
44%9%11%14%13%7%
2208
16th to endDay
40%8%13%20%13%2
2434
June1st to 15thDay
36%11%15%19%15%1
2340
16th to endDay
44%13%17%18%6%
2340
July1st to 15thDay
38%13%22%19%5%
2201
16th to endDay
41%14%20%19%3
2311
August1st to 15thDay
32%13%21%26%6%
2308
16th to endDay
43%15%18%15%5%1
2290
September1st to 15thDay
40%13%15%16%10%3
1980
16th to endDay
41%8%11%17%16%4
1859
October1st to 15thDay
31%7%8%23%14%15%
1682
16th to endDay
29%46%13%30%15%
1760
November1st to 15thDay
36%6%12%17%18%8%
1758
16th to endDay
38%5%6%12%21%16%
1788
December1st to 15thDay
47%5%10%15%14%7%
1620
16th to endDay
49%5%8%14%15%6%
1728
January1st to 15thNight
43%35%14%21%11%
2327
16th to endNight
42%37%15%18%12%
2496
February1st to 15thNight
41%38%12%19%13%
2199
16th to endNight
43%36%15%19%12%
1765
March1st to 15thNight
42%49%16%16%9%
1980
16th to endNight
35%414%16%20%9%
2112
April1st to 15thNight
38%6%11%17%15%10%
1930
16th to endNight
41%5%11%18%14%9%
1800
May1st to 15thNight
36%7%14%19%12%9%
1739
16th to endNight
29%8%18%26%13%3
1685
June1st to 15thNight
20%6%22%29%20%
1620
16th to endNight
31%10%21%25%10%
1620
July1st to 15thNight
28%9%28%27%6%
1530
16th to endNight
25%13%27%30%2
1594
August1st to 15thNight
14%7%29%39%8%
1628
16th to endNight
33%12%24%22%5%1
1910
September1st to 15thNight
32%9%23%19%12%3
1978
16th to endNight
32%8%14%21%17%6%
1870
October1st to 15thNight
22%6%12%25%19%14%
1936
16th to endNight
24%36%16%28%19%
2112
November1st to 15thNight
33%411%22%19%8%
2100
16th to endNight
32%37%16%22%16%
2169
December1st to 15thNight
45%49%17%13%7%
2340
16th to endNight
48%47%14%14%10%
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
22%427%34%11%
90
16th to endDay
12%10%33%32%11%
96
February1st to 15thDay
10%5%40%33%10%1
90
16th to endDay
14%6%33%34%9%1
81
March1st to 15thDay
32%5%34%17%10%
90
16th to endDay
16%9%27%26%14%6%
96
April1st to 15thDay
17%7%21%31%20%2
135
16th to endDay
21%322%28%21%2
270
May1st to 15thDay
13%428%33%19%1
345
16th to endDay
11%222%35%24%4
517
June1st to 15thDay
7%7%31%39%13%
495
16th to endDay
8%16%27%32%23%
495
July1st to 15thDay
6%1424%37%26%
475
16th to endDay
6%318%37%34%
515
August1st to 15thDay
3215%40%37%
475
16th to endDay
13%5%10%34%34%
330
September1st to 15thDay
7%120%35%34%
135
16th to endDay
5%5%8%37%42%
102
October1st to 15thDay
4230%48%14%
90
16th to endDay
16%114%26%26%15%
96
November1st to 15thDay
16%218%31%22%8%
90
16th to endDay
12%6%28%33%10%8%
90
December1st to 15thDay
21%418%31%16%7%
90
16th to endDay
21%10%36%23%7%
96
January1st to 15thNight
21%5%27%33%11%
900
16th to endNight
20%7%27%34%9%
960
February1st to 15thNight
20%6%27%35%9%
791
16th to endNight
19%7%32%33%6%
503
March1st to 15thNight
21%6%27%35%8%
540
16th to endNight
11%5%25%39%15%1
576
April1st to 15thNight
14%5%26%42%11%
539
16th to endNight
18%422%37%16%
540
May1st to 15thNight
11%424%45%12%
540
16th to endNight
6%117%40%31%2
563
June1st to 15thNight
4340%47%4
540
16th to endNight
7%5%24%53%8%
540
July1st to 15thNight
5%120%58%12%
510
16th to endNight
4115%62%15%
564
August1st to 15thNight
219%70%15%
539
16th to endNight
8%215%58%14%
573
September1st to 15thNight
8%5%19%54%12%
540
16th to endNight
10%423%49%9%
507
October1st to 15thNight
7%8%33%43%6%
616
16th to endNight
9%215%34%33%4
704
November1st to 15thNight
12%115%40%27%3
700
16th to endNight
13%424%36%20%1
729
December1st to 15thNight
18%6%23%33%16%1
900
16th to endNight
21%7%25%32%11%
960
Page generated at 2017-09-21 06:18:12. Version ac04

Copyright 2017 A. Danko


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