Karval Reservoir SWA
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Karval Reservoir SWA clear sky chart from 2005-11-05 to 2018-02-13.

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
54%
16560
27%
48759
18%
16515
62%
16515
40%
26822

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
55%
975
28%
2716
21%
970
62%
970
47%
1442
January16th to endNight
53%
918
35%
2790
23%
918
64%
918
47%
1405
February1st to 15thNight
46%
752
23%
2305
14%
748
56%
748
35%
1317
February16th to endNight
43%
632
33%
1894
17%
632
58%
632
42%
995
March1st to 15thNight
49%
720
27%
2160
17%
720
58%
720
41%
1175
March16th to endNight
42%
631
26%
2002
15%
631
54%
631
37%
1081
April1st to 15thNight
33%
539
23%
1798
11%
539
50%
539
35%
956
April16th to endNight
37%
540
21%
1800
16%
540
48%
540
28%
1045
May1st to 15thNight
43%
540
22%
1620
15%
540
53%
540
31%
984
May16th to endNight
42%
561
17%
1554
9%
561
51%
561
30%
985
June1st to 15thNight
49%
540
20%
1440
11%
540
56%
540
42%
821
June16th to endNight
62%
540
23%
1440
15%
540
67%
540
45%
817
July1st to 15thNight
68%
510
17%
1360
13%
510
69%
510
34%
866
July16th to endNight
73%
564
22%
1416
20%
531
73%
531
37%
888
August1st to 15thNight
67%
539
14%
1734
15%
536
69%
536
26%
1105
August16th to endNight
73%
573
24%
1910
28%
573
75%
573
38%
1017
September1st to 15thNight
62%
540
27%
1803
26%
540
69%
540
37%
973
September16th to endNight
63%
537
35%
1980
32%
537
72%
537
44%
902
October1st to 15thNight
51%
624
30%
2064
21%
624
59%
624
36%
1078
October16th to endNight
62%
845
37%
2381
23%
845
69%
845
54%
1175
November1st to 15thNight
60%
950
34%
2470
19%
950
67%
950
55%
1295
November16th to endNight
59%
975
37%
2535
22%
975
66%
975
55%
1319
December1st to 15thNight
52%
975
26%
2675
16%
975
59%
975
41%
1524
December16th to endNight
49%
1040
30%
2912
18%
1040
58%
1040
39%
1657

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
5%31332345%8%57%
49300
Night
5%42332445%7%56%
48931
Cloud CoverDay
5%41332345%7%57%
49298
Night
5%42332445%7%56%
48931
TransparencyDay
24%5%12%25%23%9%
48974
Night
26%5%12%24%22%8%
48759
SeeingDay
8%6%24%31%22%6%
6281
Night
7%5%28%39%17%1
16562

By Month

Percentage Cloud Cover SW (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
35%13323236%63%
1552
16th to endDay
3423322346%64%
1797
February1st to 15thDay
35%35%5%2445%6%54%
1820
16th to endDay
26%25%424345%58%
1580
March1st to 15thDay
331342346%7%59%
1800
16th to endDay
7%5%1342435%8%52%
2218
April1st to 15thDay
7%42432445%7%54%
2150
16th to endDay
9%4245%235%5%7%48%
2160
May1st to 15thDay
9%5%1442446%7%48%
2330
16th to endDay
7%31332445%9%54%
2559
June1st to 15thDay
5%21332345%11%56%
2520
16th to endDay
2123135%6%9%62%
2520
July1st to 15thDay
33134346%8%10%50%
2520
16th to endDay
42133245%6%12%51%
2656
August1st to 15thDay
5%3144345%7%10%49%
2215
16th to endDay
5%3123235%6%9%55%
2292
September1st to 15thDay
6%323324447%56%
2157
16th to endDay
5%212212345%66%
1980
October1st to 15thDay
7%412212335%64%
1895
16th to endDay
4212212345%68%
1830
November1st to 15thDay
3322313345%65%
1718
16th to endDay
3312212337%68%
1755
December1st to 15thDay
36%23423235%59%
1612
16th to endDay
47%34322347%56%
1664
January1st to 15thNight
25%2332335%6%60%
2716
16th to endNight
25%24322345%64%
2790
February1st to 15thNight
45%24435%446%53%
2295
16th to endNight
3313423347%59%
1894
March1st to 15thNight
5%423424346%58%
2160
16th to endNight
6%42432335%6%57%
2002
April1st to 15thNight
7%4233145%6%7%54%
1798
16th to endNight
10%6%25%423447%48%
1800
May1st to 15thNight
10%5%23324446%50%
1619
16th to endNight
10%424425%46%8%47%
1553
June1st to 15thNight
42133245%6%10%54%
1440
16th to endNight
4212425%46%10%54%
1440
July1st to 15thNight
5%325%5%35%5%9%10%43%
1440
16th to endNight
5%323436%5%7%8%48%
1512
August1st to 15thNight
6%5%25%5%46%6%7%8%41%
1742
16th to endNight
5%3133345%8%11%50%
1910
September1st to 15thNight
9%2143245%6%7%51%
1803
16th to endNight
4312313346%64%
1980
October1st to 15thNight
8%413322346%59%
2064
16th to endNight
423213245%69%
2381
November1st to 15thNight
3312223347%65%
2470
16th to endNight
3313212336%67%
2535
December1st to 15thNight
25%245%24346%57%
2675
16th to endNight
45%24424447%55%
2912

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
3423323235%64%
1552
16th to endDay
3413313336%65%
1797
February1st to 15thDay
35%345%2445%6%54%
1820
16th to endDay
25%25%425%345%58%
1580
March1st to 15thDay
331342345%6%60%
1800
16th to endDay
6%6%23425%348%53%
2216
April1st to 15thDay
6%41442445%7%53%
2150
16th to endDay
9%4245%245%5%7%48%
2160
May1st to 15thDay
9%5%2342446%7%48%
2330
16th to endDay
7%313325%5%6%8%53%
2559
June1st to 15thDay
5%3123145%5%10%56%
2520
16th to endDay
211132346%9%62%
2520
July1st to 15thDay
3313335%6%8%10%50%
2520
16th to endDay
42134246%6%12%51%
2656
August1st to 15thDay
5%3134245%8%10%48%
2215
16th to endDay
5%31332345%10%55%
2292
September1st to 15thDay
6%323324447%57%
2157
16th to endDay
5%312222345%66%
1980
October1st to 15thDay
7%412212336%64%
1895
16th to endDay
43321235%5%68%
1830
November1st to 15thDay
3313313346%64%
1718
16th to endDay
3311212336%69%
1755
December1st to 15thDay
46%14323246%59%
1612
16th to endDay
47%2432235%7%56%
1664
January1st to 15thNight
25%2332335%6%60%
2716
16th to endNight
25%24322345%64%
2790
February1st to 15thNight
45%24434446%53%
2295
16th to endNight
3414324446%59%
1894
March1st to 15thNight
5%5%23423445%58%
2160
16th to endNight
7%413323447%57%
2002
April1st to 15thNight
7%4233235%5%8%53%
1798
16th to endNight
10%6%2433435%7%48%
1800
May1st to 15thNight
11%5%2342445%7%49%
1619
16th to endNight
9%43443446%7%47%
1553
June1st to 15thNight
42133245%7%10%54%
1440
16th to endNight
42135%25%47%10%53%
1440
July1st to 15thNight
5%325%435%5%9%11%43%
1440
16th to endNight
5%413435%5%8%8%48%
1512
August1st to 15thNight
6%5%25%5%47%5%8%8%41%
1742
16th to endNight
5%3133245%7%11%50%
1910
September1st to 15thNight
8%3134146%6%7%52%
1803
16th to endNight
431321335%6%64%
1980
October1st to 15thNight
8%413322346%58%
2064
16th to endNight
4213213235%69%
2381
November1st to 15thNight
3312222437%65%
2470
16th to endNight
3314312336%67%
2535
December1st to 15thNight
25%245%24346%57%
2675
16th to endNight
45%24324346%55%
2912

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
24%210%28%27%5%
1553
16th to endDay
21%310%29%27%8%
1797
February1st to 15thDay
30%411%29%17%6%
1821
16th to endDay
27%39%24%25%9%
1580
March1st to 15thDay
20%412%26%26%9%
1800
16th to endDay
30%313%23%22%6%
2218
April1st to 15thDay
28%5%11%24%21%8%
2150
16th to endDay
32%5%14%22%17%7%
2160
May1st to 15thDay
32%6%12%25%18%4
2330
16th to endDay
26%6%17%24%17%8%
2563
June1st to 15thDay
21%6%15%24%19%12%
2520
16th to endDay
15%6%12%24%26%15%
2520
July1st to 15thDay
24%6%13%23%22%9%
2371
16th to endDay
23%7%14%27%22%5%
2489
August1st to 15thDay
26%7%16%24%15%10%
2199
16th to endDay
22%412%27%24%7%
2292
September1st to 15thDay
25%5%11%22%22%11%
2157
16th to endDay
19%47%23%33%12%
1980
October1st to 15thDay
23%39%21%31%11%
1895
16th to endDay
17%28%26%31%13%
1830
November1st to 15thDay
20%410%24%26%14%
1718
16th to endDay
16%37%24%31%15%
1755
December1st to 15thDay
26%311%28%24%5%
1612
16th to endDay
27%414%27%20%6%
1664
January1st to 15thNight
23%411%28%26%6%
2716
16th to endNight
22%39%28%29%7%
2790
February1st to 15thNight
30%5%13%28%17%4
2305
16th to endNight
24%49%25%26%9%
1894
March1st to 15thNight
26%410%21%28%8%
2160
16th to endNight
27%414%21%21%9%
2002
April1st to 15thNight
26%6%11%26%20%8%
1798
16th to endNight
34%5%14%21%18%5%
1800
May1st to 15thNight
32%7%13%22%17%5%
1620
16th to endNight
33%8%17%17%12%9%
1554
June1st to 15thNight
23%8%20%22%16%8%
1440
16th to endNight
23%7%13%23%18%13%
1440
July1st to 15thNight
32%9%15%22%13%7%
1360
16th to endNight
30%8%16%21%18%4
1416
August1st to 15thNight
36%9%15%19%11%7%
1734
16th to endNight
25%7%14%26%19%6%
1910
September1st to 15thNight
27%5%14%22%18%10%
1803
16th to endNight
20%49%22%32%9%
1980
October1st to 15thNight
26%5%10%18%27%11%
2064
16th to endNight
18%39%23%28%16%
2381
November1st to 15thNight
18%39%24%28%15%
2470
16th to endNight
19%28%25%28%15%
2535
December1st to 15thNight
27%5%10%28%22%6%
2675
16th to endNight
28%412%26%24%4
2912

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%324%34%21%2
135
16th to endDay
11%5%24%38%18%1
144
February1st to 15thDay
6%7%38%35%12%
126
16th to endDay
27%44%28%12%4
81
March1st to 15thDay
310%25%37%21%2
90
16th to endDay
14%17%31%23%11%1
258
April1st to 15thDay
10%15%39%22%9%2
269
16th to endDay
16%16%34%25%6%
270
May1st to 15thDay
12%10%29%25%17%3
467
16th to endDay
12%8%27%28%18%4
517
June1st to 15thDay
7%5%26%28%22%9%
495
16th to endDay
2421%36%30%4
495
July1st to 15thDay
6%116%29%34%11%
475
16th to endDay
6%8%34%38%11%
515
August1st to 15thDay
9%219%37%25%6%
337
16th to endDay
5%115%44%25%6%
332
September1st to 15thDay
4323%35%22%10%
312
16th to endDay
15%218%24%25%14%
135
October1st to 15thDay
8%5%20%31%22%11%
135
16th to endDay
5%428%22%27%12%
144
November1st to 15thDay
7%220%37%25%5%
135
16th to endDay
9%11%24%34%20%
135
December1st to 15thDay
6%9%31%38%11%2
135
16th to endDay
5%432%40%15%
144
January1st to 15thNight
5%429%42%16%2
975
16th to endNight
5%430%44%13%1
918
February1st to 15thNight
7%5%35%42%8%
752
16th to endNight
5%7%38%37%9%
632
March1st to 15thNight
7%5%34%37%13%1
720
16th to endNight
8%8%38%34%9%
631
April1st to 15thNight
11%9%43%29%5%
539
16th to endNight
12%13%32%31%9%
540
May1st to 15thNight
13%5%33%32%12%1
540
16th to endNight
10%5%36%33%12%
563
June1st to 15thNight
5%435%41%12%1
540
16th to endNight
5%325%48%16%
540
July1st to 15thNight
6%114%45%30%1
510
16th to endNight
7%10%43%35%2
564
August1st to 15thNight
7%14%48%27%
539
16th to endNight
6%113%45%31%2
573
September1st to 15thNight
10%219%40%25%2
540
16th to endNight
5%323%40%26%1
537
October1st to 15thNight
11%6%27%33%17%3
624
16th to endNight
5%6%23%36%25%3
845
November1st to 15thNight
4427%40%20%2
950
16th to endNight
5%6%25%40%18%3
975
December1st to 15thNight
5%5%31%42%13%1
975
16th to endNight
7%8%29%39%14%1
1040
Page generated at 2018-02-13 18:45:57. Version ac04

Copyright 2018 A. Danko


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