Brooks Camp Developed Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Brooks Camp Developed Area clear sky chart from 2005-11-05 to 2017-09-19.

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
34%
13421
5%
46601
4%
13394
35%
13394
9%
37456

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
39%
776
9%
3044
6%
776
42%
776
12%
2237
January16th to endNight
33%
807
8%
2929
6%
807
34%
807
10%
2315
February1st to 15thNight
37%
671
9%
2573
8%
669
39%
669
11%
1913
February16th to endNight
29%
501
10%
2054
7%
501
35%
501
9%
1563
March1st to 15thNight
37%
570
12%
2154
11%
570
39%
570
13%
1566
March16th to endNight
46%
603
10%
2087
10%
603
46%
603
14%
1558
April1st to 15thNight
31%
539
4%
1631
4%
539
31%
539
10%
1326
April16th to endNight
41%
508
3%
1465
2%
508
42%
508
14%
1128
May1st to 15thNight
47%
359
0%
1254
0%
359
47%
359
13%
934
May16th to endNight
41%
375
0%
1059
0%
374
41%
374
15%
829
June1st to 15thNight
33%
360
0%
900
0%
360
33%
360
11%
771
June16th to endNight
44%
360
0%
900
0%
360
44%
360
11%
777
July1st to 15thNight
43%
340
0%
850
0%
340
43%
340
11%
734
July16th to endNight
27%
376
0%
1084
0%
354
27%
354
6%
959
August1st to 15thNight
28%
358
0%
1253
0%
356
28%
356
6%
1085
August16th to endNight
25%
551
2%
1647
2%
551
26%
551
5%
1461
September1st to 15thNight
28%
540
1%
1710
1%
540
28%
540
6%
1479
September16th to endNight
28%
534
4%
1861
3%
534
29%
534
6%
1570
October1st to 15thNight
33%
525
4%
2007
5%
525
34%
525
8%
1600
October16th to endNight
32%
684
5%
2412
5%
684
33%
684
8%
1963
November1st to 15thNight
25%
730
4%
2571
3%
730
26%
730
6%
2215
November16th to endNight
33%
750
6%
2880
4%
750
35%
750
7%
2361
December1st to 15thNight
33%
772
5%
3012
4%
772
34%
772
8%
2448
December16th to endNight
31%
832
6%
3264
4%
832
32%
832
7%
2664

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
21%13%48%6%45%445%19%
48281
Night
17%13%48%7%46%5%5%5%20%
46722
TransparencyDay
66%10%11%8%2
47903
Night
62%9%12%9%4
46606
SeeingDay
26%11%23%21%13%3
9289
Night
22%9%20%25%17%4
13429

By Month

Percentage Cloud Cover NW (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
11%11%5%8%5%6%7%10%7%7%17%
895
16th to endDay
11%13%48%7%5%7%8%7%420%
1294
February1st to 15thDay
7%13%5%8%7%5%8%6%8%7%19%
1289
16th to endDay
14%15%5%9%9%47%5%5%418%
1419
March1st to 15thDay
9%9%38%6%5%7%5%45%31%
1806
16th to endDay
9%13%49%7%5%7%44428%
2131
April1st to 15thDay
13%16%6%10%7%35%34422%
2316
16th to endDay
9%13%5%9%7%35%5%5%6%26%
2493
May1st to 15thDay
16%15%5%7%6%34345%27%
2696
16th to endDay
16%12%47%7%3446%7%25%
3054
June1st to 15thDay
22%14%49%6%35%445%19%
3060
16th to endDay
25%11%46%6%36%5%5%6%18%
3060
July1st to 15thDay
28%11%47%6%34446%16%
3060
16th to endDay
39%11%46%5%3433412%
3007
August1st to 15thDay
36%12%39%5%3344411%
2700
16th to endDay
33%14%48%7%3443410%
2554
September1st to 15thDay
34%13%48%5%2443413%
2250
16th to endDay
28%13%38%6%3444417%
1841
October1st to 15thDay
23%16%47%6%3434420%
1623
16th to endDay
15%13%9%10%5%44345%21%
1460
November1st to 15thDay
16%18%6%10%8%5%5%335%15%
1285
16th to endDay
15%9%5%9%10%8%11%6%45%15%
1080
December1st to 15thDay
15%12%47%7%8%8%5%46%18%
948
16th to endDay
11%14%47%7%410%6%5%8%17%
960
January1st to 15thNight
8%12%48%8%5%7%9%6%6%20%
3044
16th to endNight
12%15%5%8%8%5%7%6%5%6%17%
2929
February1st to 15thNight
9%15%47%6%47%7%5%6%25%
2562
16th to endNight
11%14%5%8%8%45%5%5%5%25%
2054
March1st to 15thNight
10%12%49%5%46%5%45%31%
2154
16th to endNight
7%13%6%10%7%46%445%28%
2087
April1st to 15thNight
15%17%410%7%3434421%
1631
16th to endNight
9%11%5%8%8%45%6%47%27%
1465
May1st to 15thNight
19%13%26%435%437%29%
1253
16th to endNight
16%11%36%7%35%5%6%6%26%
1058
June1st to 15thNight
24%10%49%7%35%445%20%
900
16th to endNight
24%9%5%7%445%5%6%7%20%
900
July1st to 15thNight
25%9%36%6%16%6%7%7%18%
900
16th to endNight
37%12%46%423345%14%
1161
August1st to 15thNight
36%10%47%5%2435%5%14%
1260
16th to endNight
37%10%37%6%2433414%
1647
September1st to 15thNight
31%12%49%6%3433315%
1710
16th to endNight
29%12%46%6%33335%19%
1861
October1st to 15thNight
24%13%46%5%3445%5%23%
2007
16th to endNight
18%13%5%7%6%3445%6%22%
2412
November1st to 15thNight
18%17%410%9%35%43417%
2571
16th to endNight
13%11%5%8%8%7%10%5%5%5%17%
2880
December1st to 15thNight
14%14%5%9%8%6%7%6%5%5%17%
3012
16th to endNight
11%15%5%8%8%5%8%6%5%7%16%
3264

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
53%10%13%11%8%2
895
16th to endDay
56%13%10%11%6%
1294
February1st to 15thDay
56%10%12%10%6%3
1289
16th to endDay
66%10%9%9%4
1419
March1st to 15thDay
54%7%9%16%10%1
1806
16th to endDay
57%10%8%13%7%2
2131
April1st to 15thDay
66%7%12%9%4
2316
16th to endDay
57%10%14%14%2
2493
May1st to 15thDay
61%8%12%14%3
2696
16th to endDay
59%12%16%10%1
3058
June1st to 15thDay
67%10%13%7%
3060
16th to endDay
68%11%14%41
3060
July1st to 15thDay
69%11%14%4
2881
16th to endDay
78%8%7%5%
2822
August1st to 15thDay
76%9%10%3
2682
16th to endDay
80%8%7%3
2554
September1st to 15thDay
75%9%8%6%
2250
16th to endDay
72%8%9%8%1
1841
October1st to 15thDay
68%8%10%9%2
1623
16th to endDay
64%10%13%7%3
1460
November1st to 15thDay
72%10%9%7%
1285
16th to endDay
67%10%10%7%3
1080
December1st to 15thDay
62%10%13%10%2
948
16th to endDay
58%13%13%9%3
960
January1st to 15thNight
53%10%12%12%9%1
3044
16th to endNight
60%9%11%9%7%
2929
February1st to 15thNight
55%9%11%12%8%2
2573
16th to endNight
57%9%12%12%7%
2054
March1st to 15thNight
55%6%10%15%10%1
2154
16th to endNight
56%7%11%13%9%2
2092
April1st to 15thNight
64%7%12%10%4
1631
16th to endNight
54%10%15%15%4
1465
May1st to 15thNight
55%8%16%15%2
1254
16th to endNight
52%12%20%10%3
1059
June1st to 15thNight
64%11%14%9%
900
16th to endNight
64%12%16%5%1
900
July1st to 15thNight
60%16%15%7%
850
16th to endNight
71%10%12%4
1084
August1st to 15thNight
72%8%13%4
1253
16th to endNight
75%7%10%5%
1647
September1st to 15thNight
71%8%13%5%
1710
16th to endNight
69%9%10%8%2
1861
October1st to 15thNight
62%9%13%11%2
2007
16th to endNight
63%10%13%7%4
2412
November1st to 15thNight
70%9%9%8%1
2571
16th to endNight
65%9%9%9%5%1
2880
December1st to 15thNight
64%10%14%7%3
3012
16th to endNight
64%10%10%9%4
3264

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
16%11%16%21%21%12%
210
16th to endDay
15%14%26%26%11%6%
224
February1st to 15thDay
13%11%30%22%14%7%
207
16th to endDay
23%16%26%22%9%1
211
March1st to 15thDay
13%14%30%25%12%2
348
16th to endDay
12%10%27%29%18%2
448
April1st to 15thDay
21%13%26%23%12%3
419
16th to endDay
11%12%29%25%15%4
441
May1st to 15thDay
19%9%21%26%20%2
468
16th to endDay
21%13%28%22%10%3
581
June1st to 15thDay
26%10%24%22%13%3
675
16th to endDay
26%6%21%28%13%3
675
July1st to 15thDay
31%7%20%23%14%2
645
16th to endDay
38%10%22%17%9%2
593
August1st to 15thDay
39%8%22%16%10%2
494
16th to endDay
40%13%22%15%6%1
487
September1st to 15thDay
39%11%21%16%8%2
450
16th to endDay
40%9%20%17%7%5%
386
October1st to 15thDay
34%12%20%16%14%2
225
16th to endDay
22%14%22%20%17%3
240
November1st to 15thDay
20%17%27%16%12%4
218
16th to endDay
21%13%19%21%16%8%
210
December1st to 15thDay
18%10%24%18%18%10%
210
16th to endDay
19%16%23%21%13%5%
224
January1st to 15thNight
13%10%20%30%20%5%
780
16th to endNight
16%11%22%30%14%3
807
February1st to 15thNight
14%14%21%28%15%5%
673
16th to endNight
16%13%26%26%14%2
501
March1st to 15thNight
11%9%27%31%17%2
570
16th to endNight
11%218%37%22%6%
604
April1st to 15thNight
21%8%22%24%18%3
539
16th to endNight
12%9%23%27%20%6%
508
May1st to 15thNight
21%315%27%29%3
360
16th to endNight
19%5%22%24%24%2
375
June1st to 15thNight
28%418%25%20%3
360
16th to endNight
28%314%20%29%4
360
July1st to 15thNight
29%411%25%22%5%
340
16th to endNight
41%5%17%17%13%4
376
August1st to 15thNight
37%6%16%18%17%3
358
16th to endNight
41%8%14%20%14%1
551
September1st to 15thNight
37%8%15%20%15%2
540
16th to endNight
38%6%17%16%15%5%
534
October1st to 15thNight
30%11%18%17%17%4
525
16th to endNight
25%10%20%23%15%4
684
November1st to 15thNight
26%11%22%19%16%3
730
16th to endNight
19%10%23%26%16%3
750
December1st to 15thNight
17%12%23%23%15%7%
772
16th to endNight
18%13%24%25%14%3
832
Page generated at 2017-09-20 00:49:46. Version ac04

Copyright 2017 A. Danko


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