Catahoula Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Catahoula 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
49%
15487
24%
47055
17%
15441
56%
15441
31%
28223

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
30%
900
25%
2327
9%
895
41%
895
29%
1501
January16th to endNight
27%
960
25%
2496
8%
960
37%
960
29%
1646
February1st to 15thNight
32%
778
24%
2186
10%
775
42%
775
28%
1382
February16th to endNight
24%
588
25%
1850
9%
588
36%
588
24%
1179
March1st to 15thNight
29%
540
24%
1980
14%
540
42%
540
21%
1207
March16th to endNight
39%
576
23%
2112
16%
576
50%
576
29%
1178
April1st to 15thNight
36%
539
24%
1800
15%
539
49%
539
31%
1023
April16th to endNight
41%
540
25%
1800
19%
540
54%
540
30%
1051
May1st to 15thNight
40%
539
20%
1800
14%
539
52%
539
32%
1024
May16th to endNight
57%
563
23%
1777
22%
561
63%
561
34%
1027
June1st to 15thNight
76%
540
18%
1620
19%
540
78%
540
39%
907
June16th to endNight
72%
540
19%
1620
21%
540
73%
540
31%
997
July1st to 15thNight
77%
510
17%
1530
19%
510
79%
510
36%
889
July16th to endNight
78%
564
17%
1594
20%
531
78%
531
33%
972
August1st to 15thNight
82%
539
17%
1751
21%
536
83%
536
36%
959
August16th to endNight
71%
573
16%
1910
19%
573
72%
573
23%
1255
September1st to 15thNight
72%
540
22%
1800
25%
540
73%
540
30%
1077
September16th to endNight
69%
607
31%
1959
29%
607
71%
607
35%
1101
October1st to 15thNight
63%
684
30%
2052
24%
684
67%
684
41%
1103
October16th to endNight
57%
704
35%
2112
27%
704
63%
704
42%
1125
November1st to 15thNight
50%
700
32%
2100
22%
700
59%
700
37%
1168
November16th to endNight
42%
720
32%
2160
21%
720
52%
720
35%
1240
December1st to 15thNight
34%
783
25%
2223
14%
783
44%
783
25%
1465
December16th to endNight
30%
960
20%
2496
9%
960
36%
960
24%
1747

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%5%35%5%5%7%40%
48135
Night
11%42442445%7%48%
47252
TransparencyDay
42%5%10%18%17%5%
47836
Night
34%5%11%19%19%8%
47056
SeeingDay
12%5%15%24%28%13%
5557
Night
14%6%24%29%21%4
15488

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%24422345%45%
1611
16th to endDay
20%7%34423335%41%
1728
February1st to 15thDay
17%7%35%5%2334344%
1675
16th to endDay
17%8%27%423345%40%
1634
March1st to 15thDay
19%7%35%424345%38%
1980
16th to endDay
11%6%36%5%34347%42%
2110
April1st to 15thDay
12%6%35%5%24447%43%
2148
16th to endDay
13%6%26%5%45%5%6%7%37%
2160
May1st to 15thDay
12%7%36%7%345%5%8%36%
2151
16th to endDay
8%5%26%6%47%6%7%8%36%
2334
June1st to 15thDay
6%426%7%5%7%7%7%9%33%
2340
16th to endDay
7%435%6%5%8%8%8%10%31%
2340
July1st to 15thDay
8%425%7%47%7%8%10%31%
2340
16th to endDay
8%5%37%7%48%8%8%8%28%
2466
August1st to 15thDay
7%425%6%47%7%7%9%38%
2196
16th to endDay
13%6%26%6%46%6%6%8%31%
2292
September1st to 15thDay
11%5%25%6%45%6%6%7%39%
2160
16th to endDay
10%4245%45%447%46%
1984
October1st to 15thDay
8%4135%33245%56%
1706
16th to endDay
12%414222335%58%
1760
November1st to 15thDay
10%425%324446%51%
1758
16th to endDay
14%6%24433245%48%
1800
December1st to 15thDay
17%9%25%423335%40%
1734
16th to endDay
21%7%25%5%13345%37%
1728
January1st to 15thNight
16%5%25%423336%47%
2327
16th to endNight
19%6%24323435%45%
2496
February1st to 15thNight
15%6%24423446%46%
2177
16th to endNight
18%6%25%323245%44%
1850
March1st to 15thNight
17%6%24423336%44%
1980
16th to endNight
11%5%24323346%50%
2112
April1st to 15thNight
9%41442446%7%50%
1800
16th to endNight
10%3245%2435%8%47%
1800
May1st to 15thNight
8%5%24425%46%9%46%
1799
16th to endNight
8%32443435%8%49%
1776
June1st to 15thNight
3314425%5%7%10%50%
1620
16th to endNight
6%3345%25%7%8%10%43%
1620
July1st to 15thNight
6%3233245%8%11%48%
1620
16th to endNight
5%325%5%35%5%7%12%44%
1702
August1st to 15thNight
3213435%5%7%14%47%
1761
16th to endNight
8%325%6%46%6%8%11%36%
1910
September1st to 15thNight
8%4245%345%6%8%46%
1800
16th to endNight
8%5%1343445%5%53%
1959
October1st to 15thNight
6%313334346%57%
2052
16th to endNight
11%31221233461%
2112
November1st to 15thNight
10%323324346%55%
2100
16th to endNight
13%424322335%54%
2160
December1st to 15thNight
17%6%35%423346%42%
2223
16th to endNight
19%9%35%423345%39%
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
41%25%19%22%8%
1612
16th to endDay
46%25%14%22%9%
1728
February1st to 15thDay
45%26%15%21%9%
1677
16th to endDay
46%36%16%19%8%
1634
March1st to 15thDay
48%38%15%17%5%
1980
16th to endDay
43%38%16%24%4
2112
April1st to 15thDay
41%38%21%18%7%
2148
16th to endDay
43%5%8%18%18%5%
2160
May1st to 15thDay
45%5%12%15%15%6%
2151
16th to endDay
41%6%12%24%13%1
2338
June1st to 15thDay
42%8%13%20%13%1
2340
16th to endDay
42%10%14%19%11%
2340
July1st to 15thDay
41%10%19%18%8%1
2201
16th to endDay
45%10%17%19%6%
2311
August1st to 15thDay
37%9%19%22%9%1
2182
16th to endDay
47%10%15%14%9%2
2292
September1st to 15thDay
40%7%14%19%12%5%
2160
16th to endDay
37%5%10%20%19%6%
1984
October1st to 15thDay
30%48%18%22%16%
1706
16th to endDay
30%2415%33%14%
1760
November1st to 15thDay
33%37%18%28%8%
1758
16th to endDay
39%25%13%27%12%
1800
December1st to 15thDay
47%28%18%16%6%
1734
16th to endDay
49%26%18%16%5%
1728
January1st to 15thNight
39%35%16%23%11%
2327
16th to endNight
41%36%16%22%9%
2496
February1st to 15thNight
39%36%17%22%10%
2186
16th to endNight
43%25%16%18%12%
1850
March1st to 15thNight
42%37%14%22%8%
1980
16th to endNight
34%312%19%22%6%
2112
April1st to 15thNight
31%5%11%22%18%10%
1800
16th to endNight
34%5%9%22%20%8%
1800
May1st to 15thNight
33%5%15%19%16%10%
1800
16th to endNight
32%5%13%26%20%1
1778
June1st to 15thNight
26%7%18%28%16%1
1620
16th to endNight
31%10%17%24%15%
1620
July1st to 15thNight
25%11%28%22%10%1
1530
16th to endNight
30%10%25%22%10%
1594
August1st to 15thNight
24%9%26%25%12%1
1751
16th to endNight
38%12%19%15%11%2
1910
September1st to 15thNight
33%7%15%21%14%6%
1800
16th to endNight
30%5%10%19%22%11%
1959
October1st to 15thNight
27%38%18%25%15%
2052
16th to endNight
27%25%14%28%21%
2112
November1st to 15thNight
30%38%18%27%11%
2100
16th to endNight
33%27%13%26%16%
2160
December1st to 15thNight
43%38%18%19%6%
2223
16th to endNight
48%26%17%18%6%
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
24%13%28%24%7%1
90
16th to endDay
16%21%44%11%5%
96
February1st to 15thDay
13%22%36%23%4
90
16th to endDay
16%17%49%14%2
81
March1st to 15thDay
25%24%32%16%1
90
16th to endDay
18%11%25%30%12%2
96
April1st to 15thDay
17%14%28%24%13%2
267
16th to endDay
18%7%25%25%21%1
270
May1st to 15thDay
15%5%25%32%14%5%
288
16th to endDay
14%420%30%23%6%
421
June1st to 15thDay
9%210%34%35%9%
495
16th to endDay
8%29%27%35%17%
495
July1st to 15thDay
6%15%25%40%22%
475
16th to endDay
6%5%17%44%25%
515
August1st to 15thDay
10%1218%41%25%
349
16th to endDay
17%1412%37%26%
332
September1st to 15thDay
8%26%21%35%25%
315
16th to endDay
7%8%24%33%26%
223
October1st to 15thDay
3117%39%28%8%
107
16th to endDay
16%419%16%30%12%
96
November1st to 15thDay
18%7%33%28%11%
90
16th to endDay
20%11%32%21%12%3
90
December1st to 15thDay
23%7%34%18%12%3
90
16th to endDay
21%25%29%21%2
96
January1st to 15thNight
19%13%32%25%9%
900
16th to endNight
21%10%37%24%5%
960
February1st to 15thNight
18%13%33%28%6%
778
16th to endNight
22%14%36%22%3
588
March1st to 15thNight
18%11%36%27%5%
540
16th to endNight
13%8%35%30%11%
576
April1st to 15thNight
11%10%39%27%10%
539
16th to endNight
12%7%35%30%13%
540
May1st to 15thNight
10%5%37%30%14%
540
16th to endNight
8%323%37%23%3
563
June1st to 15thNight
410%45%34%4
540
16th to endNight
7%18%35%35%12%
540
July1st to 15thNight
5%5%34%42%10%
510
16th to endNight
5%329%44%15%
564
August1st to 15thNight
5%327%46%16%
539
16th to endNight
10%1429%40%14%
573
September1st to 15thNight
10%17%32%38%10%
540
16th to endNight
11%19%27%42%7%
607
October1st to 15thNight
8%218%31%33%4
684
16th to endNight
14%420%32%24%4
704
November1st to 15thNight
12%5%26%32%21%1
700
16th to endNight
15%7%30%29%15%1
720
December1st to 15thNight
21%12%27%28%10%
783
16th to endNight
24%11%30%25%8%
960
Page generated at 2017-10-07 13:07:45. Version ac04

Copyright 2017 A. Danko


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