Gros Morne National Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Gros Morne National Park clear sky chart from 2005-11-05 to 2017-09-23.

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
18%
15121
5%
46876
3%
15081
20%
15081
7%
40598

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
6%
746
3%
2547
2%
746
8%
746
1%
2413
January16th to endNight
10%
800
4%
2688
3%
800
11%
800
2%
2511
February1st to 15thNight
8%
724
2%
2417
1%
723
9%
723
2%
2285
February16th to endNight
13%
631
2%
1918
0%
631
15%
631
4%
1728
March1st to 15thNight
14%
717
6%
2148
3%
716
16%
716
6%
1893
March16th to endNight
16%
615
7%
2010
4%
615
21%
615
5%
1743
April1st to 15thNight
18%
539
7%
1796
5%
539
21%
539
6%
1517
April16th to endNight
22%
540
10%
1594
6%
540
26%
540
11%
1277
May1st to 15thNight
33%
540
8%
1440
4%
540
35%
540
17%
1103
May16th to endNight
27%
561
5%
1400
2%
560
28%
560
12%
1152
June1st to 15thNight
32%
540
3%
1260
2%
540
32%
540
14%
1051
June16th to endNight
29%
540
2%
1260
1%
540
30%
540
17%
993
July1st to 15thNight
31%
510
3%
1242
2%
510
32%
510
17%
965
July16th to endNight
33%
565
5%
1419
3%
532
35%
532
15%
1139
August1st to 15thNight
32%
539
6%
1429
2%
535
34%
535
14%
1140
August16th to endNight
31%
573
8%
1776
6%
573
34%
573
14%
1360
September1st to 15thNight
23%
540
6%
1803
4%
540
26%
540
10%
1441
September16th to endNight
17%
517
7%
1901
5%
517
20%
517
7%
1510
October1st to 15thNight
16%
618
7%
1958
4%
618
18%
618
7%
1632
October16th to endNight
14%
736
5%
2288
3%
736
15%
736
5%
1998
November1st to 15thNight
13%
730
4%
2334
2%
730
14%
730
4%
2106
November16th to endNight
9%
750
4%
2668
2%
750
11%
750
2%
2413
December1st to 15thNight
6%
750
3%
2700
1%
750
9%
750
2%
2513
December16th to endNight
9%
800
2%
2880
2%
800
10%
800
1%
2715

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
24%14%6%9%7%3333418%
48027
Night
22%17%7%10%8%3333414%
47054
TransparencyDay
70%48%11%3
47710
Night
75%47%9%3
46889
SeeingDay
33%15%23%17%7%2
8076
Night
32%17%22%18%7%1
15130

By Month

Percentage Cloud Cover NE (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%18%12%21%12%5%42213
1388
16th to endDay
10%18%10%17%19%7%6%1114
1536
February1st to 15thDay
11%15%9%16%18%8%5%3234
1442
16th to endDay
11%20%10%17%12%5%322210%
1554
March1st to 15thDay
14%17%8%13%10%45%43314%
1790
16th to endDay
14%20%9%12%9%5%322314%
2213
April1st to 15thDay
19%19%8%10%7%23335%15%
2153
16th to endDay
20%12%5%10%5%23336%25%
2365
May1st to 15thDay
25%12%46%423435%27%
2512
16th to endDay
29%14%36%424445%21%
2711
June1st to 15thDay
28%11%36%6%345%46%19%
2700
16th to endDay
28%10%36%424335%26%
2700
July1st to 15thDay
27%7%25%4245%5%5%28%
2642
16th to endDay
30%8%45%5%24345%24%
2653
August1st to 15thDay
25%9%35%5%3345%7%26%
2520
16th to endDay
34%8%25%42335%6%24%
2425
September1st to 15thDay
35%9%24424335%24%
2157
16th to endDay
34%9%35%423446%20%
1896
October1st to 15thDay
32%17%3441333421%
1669
16th to endDay
35%24%5%5%41222211%
1584
November1st to 15thDay
29%27%8%6%41332310%
1523
16th to endDay
22%26%9%14%41122310%
1290
December1st to 15thDay
18%21%12%17%12%312224
1260
16th to endDay
17%21%11%16%11%6%32116%
1344
January1st to 15thNight
13%23%12%17%11%6%41225%
2547
16th to endNight
12%15%10%16%17%7%7%2225%
2688
February1st to 15thNight
13%16%9%14%20%8%6%2115%
2417
16th to endNight
10%17%8%17%14%4434410%
1918
March1st to 15thNight
14%17%8%12%11%6%5%33413%
2147
16th to endNight
14%21%9%11%8%4423413%
2010
April1st to 15thNight
21%21%7%10%6%2233415%
1796
16th to endNight
16%15%5%10%6%24445%23%
1594
May1st to 15thNight
24%12%37%32335%5%29%
1440
16th to endNight
28%12%36%6%2433423%
1398
June1st to 15thNight
23%10%48%7%35%45%5%22%
1260
16th to endNight
26%9%36%41335%6%27%
1260
July1st to 15thNight
31%7%25%424445%27%
1316
16th to endNight
31%8%36%5%34445%23%
1515
August1st to 15thNight
28%7%36%5%4346%5%24%
1440
16th to endNight
32%7%25%423346%26%
1776
September1st to 15thNight
36%8%35%433335%22%
1803
16th to endNight
37%9%25%333346%18%
1901
October1st to 15thNight
31%19%35%42434317%
1958
16th to endNight
34%24%45%41223412%
2288
November1st to 15thNight
27%28%7%6%42322310%
2334
16th to endNight
25%26%12%10%4121238%
2668
December1st to 15thNight
19%22%12%17%9%321126%
2700
16th to endNight
16%21%13%16%11%6%21125%
2880

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
90%232
1389
16th to endDay
91%2221
1536
February1st to 15thDay
86%4341
1445
16th to endDay
82%326%4
1554
March1st to 15thDay
75%46%8%5%
1800
16th to endDay
77%45%6%5%
2213
April1st to 15thDay
73%46%10%3
2153
16th to endDay
63%47%14%9%
2365
May1st to 15thDay
60%6%7%17%7%
2512
16th to endDay
66%5%9%13%4
2715
June1st to 15thDay
65%7%10%13%2
2700
16th to endDay
61%412%15%5%
2700
July1st to 15thDay
55%6%15%18%3
2488
16th to endDay
63%411%17%3
2486
August1st to 15thDay
57%6%16%16%2
2506
16th to endDay
60%5%14%15%3
2425
September1st to 15thDay
63%5%11%15%3
2157
16th to endDay
64%5%12%13%4
1896
October1st to 15thDay
67%48%12%5%1
1669
16th to endDay
81%35%7%2
1584
November1st to 15thDay
82%35%7%
1523
16th to endDay
82%446%2
1290
December1st to 15thDay
89%333
1260
16th to endDay
89%2232
1344
January1st to 15thNight
88%3331
2547
16th to endNight
87%2232
2688
February1st to 15thNight
88%334
2418
16th to endNight
79%5%45%4
1918
March1st to 15thNight
76%5%5%10%3
2160
16th to endNight
77%349%4
2010
April1st to 15thNight
73%46%12%3
1796
16th to endNight
63%5%8%11%10%
1594
May1st to 15thNight
56%5%10%17%7%1
1440
16th to endNight
65%5%8%15%5%
1400
June1st to 15thNight
63%7%8%16%3
1260
16th to endNight
57%6%15%15%4
1260
July1st to 15thNight
57%5%14%18%3
1242
16th to endNight
61%5%11%16%3
1419
August1st to 15thNight
60%7%14%14%3
1429
16th to endNight
59%5%14%16%4
1776
September1st to 15thNight
66%5%9%16%2
1803
16th to endNight
67%412%12%3
1901
October1st to 15thNight
72%38%10%4
1958
16th to endNight
77%46%9%2
2288
November1st to 15thNight
80%5%47%1
2334
16th to endNight
83%35%5%2
2668
December1st to 15thNight
88%244
2700
16th to endNight
88%3232
2880

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%38%25%7%4
240
16th to endDay
25%28%22%17%41
256
February1st to 15thDay
22%30%30%10%5%
236
16th to endDay
24%22%29%12%9%1
212
March1st to 15thDay
23%30%24%11%7%2
240
16th to endDay
29%23%24%15%5%1
280
April1st to 15thDay
32%21%24%15%5%1
270
16th to endDay
27%18%24%20%6%2
442
May1st to 15thDay
29%11%21%22%11%2
468
16th to endDay
35%9%24%18%9%2
519
June1st to 15thDay
35%8%20%22%9%3
495
16th to endDay
36%10%25%17%7%2
495
July1st to 15thDay
32%9%23%20%11%2
475
16th to endDay
35%5%21%25%10%2
514
August1st to 15thDay
29%7%27%20%11%2
493
16th to endDay
33%9%22%21%9%3
445
September1st to 15thDay
45%9%27%14%3
314
16th to endDay
43%14%23%15%21
246
October1st to 15thDay
41%17%18%11%6%4
225
16th to endDay
53%14%15%7%7%1
240
November1st to 15thDay
42%17%19%14%4
235
16th to endDay
35%21%26%12%3
240
December1st to 15thDay
31%29%23%10%5%
240
16th to endDay
28%30%23%10%5%1
256
January1st to 15thNight
28%32%23%12%2
750
16th to endNight
24%27%29%14%4
800
February1st to 15thNight
23%29%26%15%4
726
16th to endNight
22%18%32%15%9%2
631
March1st to 15thNight
22%24%28%18%5%1
720
16th to endNight
26%20%27%17%6%
615
April1st to 15thNight
33%12%24%21%6%1
539
16th to endNight
26%15%26%20%8%2
540
May1st to 15thNight
30%10%18%25%12%2
540
16th to endNight
36%9%21%22%8%1
561
June1st to 15thNight
29%9%19%29%10%
540
16th to endNight
30%7%25%24%10%1
540
July1st to 15thNight
35%5%20%21%15%
510
16th to endNight
36%6%16%27%12%
565
August1st to 15thNight
30%7%19%25%15%1
539
16th to endNight
34%6%19%20%15%2
573
September1st to 15thNight
43%9%19%21%5%
540
16th to endNight
42%12%23%17%3
517
October1st to 15thNight
45%14%17%13%6%1
618
16th to endNight
50%13%15%14%5%
736
November1st to 15thNight
40%20%17%15%5%
730
16th to endNight
40%23%19%12%21
750
December1st to 15thNight
33%24%26%13%2
750
16th to endNight
28%27%22%14%5%1
800
Page generated at 2017-09-24 10:45:51. Version ac04

Copyright 2017 A. Danko


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