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 2019-06-02.

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
17%
17528
4%
53840
2%
17486
19%
17486
6%
46916

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
7%
897
2%
2972
1%
896
8%
896
1%
2845
January16th to endNight
9%
960
2%
3136
2%
960
10%
960
2%
2961
February1st to 15thNight
8%
867
2%
2829
1%
865
9%
865
2%
2683
February16th to endNight
14%
735
2%
2234
0%
735
15%
735
4%
2003
March1st to 15thNight
15%
837
5%
2508
2%
836
17%
836
6%
2191
March16th to endNight
15%
718
5%
2345
3%
718
19%
718
5%
2035
April1st to 15thNight
17%
629
5%
2096
4%
629
19%
629
6%
1785
April16th to endNight
21%
623
8%
1840
5%
623
25%
623
10%
1511
May1st to 15thNight
31%
630
9%
1680
4%
630
33%
630
16%
1303
May16th to endNight
25%
657
5%
1644
2%
656
27%
656
13%
1355
June1st to 15thNight
30%
589
2%
1374
2%
589
31%
589
12%
1159
June16th to endNight
28%
585
2%
1365
1%
585
29%
585
16%
1103
July1st to 15thNight
31%
555
4%
1353
2%
555
32%
555
18%
1041
July16th to endNight
31%
613
5%
1547
3%
580
33%
580
14%
1241
August1st to 15thNight
32%
574
5%
1522
2%
570
34%
570
14%
1207
August16th to endNight
30%
621
7%
1925
6%
621
33%
621
13%
1491
September1st to 15thNight
24%
585
7%
1953
5%
585
28%
585
10%
1523
September16th to endNight
17%
583
7%
2145
4%
583
21%
583
7%
1720
October1st to 15thNight
14%
734
7%
2314
3%
734
17%
734
7%
1931
October16th to endNight
14%
896
5%
2704
3%
896
15%
896
6%
2368
November1st to 15thNight
13%
880
4%
2733
2%
880
14%
880
4%
2479
November16th to endNight
10%
900
3%
3111
2%
900
11%
900
3%
2831
December1st to 15thNight
8%
900
1%
3150
0%
900
9%
900
2%
2963
December16th to endNight
9%
960
1%
3360
1%
960
9%
960
1%
3187

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%15%6%9%7%3333418%
54496
Night
22%17%7%11%8%4433414%
54018
TransparencyDay
71%49%10%3
54180
Night
75%5%7%8%3
53853
SeeingDay
30%19%25%16%6%1
10322
Night
29%20%24%18%6%
17535

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%17%12%21%13%5%42214
1624
16th to endDay
11%18%10%17%19%7%5%2114
1792
February1st to 15thDay
11%15%9%16%19%8%5%2234
1691
16th to endDay
11%19%10%16%11%6%432210%
1810
March1st to 15thDay
13%16%8%13%10%5%6%43313%
2090
16th to endDay
14%20%9%12%10%4322315%
2582
April1st to 15thDay
18%20%8%11%7%2334414%
2513
16th to endDay
22%13%5%9%5%23335%23%
2723
May1st to 15thDay
23%13%46%423435%27%
2932
16th to endDay
27%15%36%424445%21%
3174
June1st to 15thDay
27%12%36%5%24446%20%
2940
16th to endDay
28%10%36%424245%26%
2925
July1st to 15thDay
26%7%25%5%345%5%5%28%
2860
16th to endDay
30%8%35%5%34345%24%
2877
August1st to 15thDay
25%9%35%5%3345%7%26%
2680
16th to endDay
33%7%25%42335%6%25%
2627
September1st to 15thDay
34%8%24423336%24%
2337
16th to endDay
34%10%35%423445%20%
2145
October1st to 15thDay
31%17%3441333422%
1973
16th to endDay
34%26%5%5%41222311%
1872
November1st to 15thDay
28%27%8%6%41322310%
1783
16th to endDay
21%26%9%14%5%1122310%
1508
December1st to 15thDay
17%20%13%17%12%322225%
1470
16th to endDay
16%21%11%18%11%6%32115%
1568
January1st to 15thNight
13%22%11%17%12%6%42224
2972
16th to endNight
12%16%10%16%17%7%7%2224
3136
February1st to 15thNight
13%15%8%15%20%8%6%2115%
2829
16th to endNight
10%16%8%16%14%5%434411%
2234
March1st to 15thNight
12%16%7%13%12%6%5%435%13%
2507
16th to endNight
14%21%9%11%9%4423413%
2345
April1st to 15thNight
20%21%7%12%6%2233415%
2096
16th to endNight
17%15%5%9%6%2445%5%22%
1840
May1st to 15thNight
22%13%37%323345%29%
1680
16th to endNight
27%13%36%5%24335%23%
1642
June1st to 15thNight
23%10%48%7%36%45%5%21%
1374
16th to endNight
26%10%36%5%23346%26%
1365
July1st to 15thNight
30%7%25%424445%28%
1427
16th to endNight
30%8%36%5%34445%23%
1643
August1st to 15thNight
27%7%36%5%3346%5%24%
1533
16th to endNight
31%7%25%423345%26%
1925
September1st to 15thNight
35%8%35%5%33345%22%
1953
16th to endNight
37%10%25%333346%18%
2145
October1st to 15thNight
31%18%35%42334417%
2314
16th to endNight
33%24%46%41223412%
2704
November1st to 15thNight
27%29%7%6%42322310%
2733
16th to endNight
23%27%12%11%4122238%
3111
December1st to 15thNight
17%22%12%18%8%321126%
3150
16th to endNight
15%21%12%18%11%6%22125%
3360

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
89%332
1625
16th to endDay
90%4121
1792
February1st to 15thDay
86%4341
1694
16th to endDay
81%336%4
1810
March1st to 15thDay
74%47%7%4
2100
16th to endDay
77%45%6%6%
2582
April1st to 15thDay
76%36%8%3
2513
16th to endDay
65%47%12%8%
2723
May1st to 15thDay
61%5%8%16%7%
2932
16th to endDay
65%5%11%12%4
3178
June1st to 15thDay
66%6%11%12%2
2940
16th to endDay
62%5%12%14%4
2925
July1st to 15thDay
55%6%14%18%4
2707
16th to endDay
63%5%12%15%3
2710
August1st to 15thDay
60%6%15%14%2
2666
16th to endDay
61%5%14%14%4
2627
September1st to 15thDay
62%412%15%3
2337
16th to endDay
65%5%12%12%4
2145
October1st to 15thDay
67%39%13%5%
1973
16th to endDay
82%35%6%2
1872
November1st to 15thDay
82%37%6%
1783
16th to endDay
84%35%5%1
1508
December1st to 15thDay
89%5%31
1470
16th to endDay
89%3231
1568
January1st to 15thNight
88%422
2972
16th to endNight
86%5%232
3136
February1st to 15thNight
86%5%33
2830
16th to endNight
79%5%5%5%4
2234
March1st to 15thNight
74%6%7%9%3
2520
16th to endNight
76%46%7%4
2345
April1st to 15thNight
74%48%9%3
2096
16th to endNight
65%6%8%10%7%
1840
May1st to 15thNight
57%6%11%15%7%1
1680
16th to endNight
64%6%10%14%4
1644
June1st to 15thNight
64%8%8%14%3
1374
16th to endNight
58%7%14%14%4
1365
July1st to 15thNight
55%6%13%19%5%
1353
16th to endNight
60%7%12%16%3
1547
August1st to 15thNight
60%6%17%13%2
1522
16th to endNight
60%5%14%14%4
1925
September1st to 15thNight
63%5%11%16%3
1953
16th to endNight
67%5%11%11%3
2145
October1st to 15thNight
72%48%9%5%
2314
16th to endNight
77%47%8%2
2704
November1st to 15thNight
81%446%2
2733
16th to endNight
83%45%41
3111
December1st to 15thNight
88%343
3150
16th to endNight
89%3221
3360

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
20%33%30%11%3
330
16th to endDay
24%28%27%13%31
352
February1st to 15thDay
21%35%25%12%4
326
16th to endDay
22%29%27%11%7%1
290
March1st to 15thDay
22%32%23%13%5%2
330
16th to endDay
25%25%27%15%5%1
399
April1st to 15thDay
26%33%24%12%21
390
16th to endDay
30%18%24%18%6%1
576
May1st to 15thDay
26%15%27%18%9%1
618
16th to endDay
29%16%26%18%6%2
679
June1st to 15thDay
30%12%24%20%9%2
575
16th to endDay
34%14%25%16%5%2
570
July1st to 15thDay
27%12%25%21%10%2
550
16th to endDay
32%8%23%25%8%1
594
August1st to 15thDay
28%8%28%21%10%2
550
16th to endDay
31%9%24%22%9%2
517
September1st to 15thDay
40%13%27%13%4
374
16th to endDay
38%17%26%13%2
314
October1st to 15thDay
37%23%22%10%32
315
16th to endDay
48%17%16%8%7%1
336
November1st to 15thDay
38%23%20%12%41
325
16th to endDay
31%23%27%13%3
330
December1st to 15thDay
25%29%27%15%2
330
16th to endDay
25%30%27%9%5%1
352
January1st to 15thNight
23%33%25%12%3
900
16th to endNight
23%30%28%13%3
960
February1st to 15thNight
22%30%24%17%4
868
16th to endNight
18%22%32%17%7%2
735
March1st to 15thNight
20%25%28%19%4
840
16th to endNight
22%22%30%17%5%
718
April1st to 15thNight
28%20%23%20%5%
629
16th to endNight
26%17%26%20%8%1
623
May1st to 15thNight
26%12%23%24%10%1
630
16th to endNight
32%13%22%22%7%
657
June1st to 15thNight
26%11%21%28%10%
589
16th to endNight
26%11%26%26%8%1
585
July1st to 15thNight
29%8%24%22%13%
555
16th to endNight
32%7%19%29%10%
613
August1st to 15thNight
27%8%22%26%13%
574
16th to endNight
29%8%23%21%14%1
621
September1st to 15thNight
37%11%20%24%5%
585
16th to endNight
37%17%23%16%4
583
October1st to 15thNight
39%18%22%12%5%1
734
16th to endNight
43%17%18%13%5%
896
November1st to 15thNight
36%22%19%15%6%
880
16th to endNight
36%23%22%13%21
900
December1st to 15thNight
27%26%26%16%3
900
16th to endNight
25%27%25%14%41
960
Page generated at 2019-06-02 20:43:05. Version ac04

Copyright 2019 A. Danko


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