Burris Fork Creek Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Burris Fork Creek Observatory clear sky chart from 2005-11-06 to 2024-11-05.

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 Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(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

By Month

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 Forecast	Data Points
Cloud Cover	Day	12% 8% 3 6% 4 4 4 3 5% 7% 43%	101223
	Night	12% 8% 3 6% 4 4 4 3 5% 6% 45%	97904
Transparency	Day	39% 4 12% 26% 17% 3	104865
	Night	38% 4 11% 25% 18% 3	102402
Seeing	Day	17% 8% 26% 27% 17% 5%	15639
	Night	16% 8% 29% 31% 14% 1	25444

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
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	13% 13% 4 8% 4 4 4 3 5% 6% 36%	2691
	11th to 20th	Day	12% 13% 4 8% 5% 7% 5% 3 4 4 36%	2850
	21st to end	Day	17% 15% 5% 8% 4 3 4 2 3 5% 33%	3135
February	1st to 10th	Day	15% 11% 4 9% 5% 4 4 3 5% 5% 35%	1710
	11th to 20th	Day	14% 11% 3 5% 5% 4 4 3 5% 6% 41%	1704
	21st to end	Day	16% 10% 4 7% 4 3 4 3 5% 6% 38%	1570
March	1st to 10th	Day	17% 10% 3 6% 3 3 3 2 4 5% 45%	3431
	11th to 20th	Day	12% 8% 2 4 4 3 3 3 4 6% 51%	3480
	21st to end	Day	17% 13% 3 8% 5% 4 4 3 5% 7% 32%	3840
April	1st to 10th	Day	12% 8% 3 7% 5% 4 4 3 5% 6% 43%	2280
	11th to 20th	Day	17% 7% 2 6% 4 4 4 3 4 7% 41%	2254
	21st to end	Day	20% 9% 3 7% 3 3 4 3 5% 6% 35%	2280
May	1st to 10th	Day	15% 8% 2 8% 5% 5% 4 4 6% 8% 34%	4008
	11th to 20th	Day	15% 8% 3 6% 5% 4 5% 3 5% 7% 39%	4196
	21st to end	Day	11% 7% 2 7% 4 4 5% 4 5% 8% 43%	4824
June	1st to 10th	Day	7% 4 2 5% 5% 4 5% 4 7% 9% 46%	2660
	11th to 20th	Day	8% 4 1 5% 5% 4 5% 4 6% 10% 48%	2660
	21st to end	Day	5% 3 2 5% 5% 4 4 4 7% 9% 50%	2660
July	1st to 10th	Day	13% 6% 3 6% 4 4 4 4 5% 8% 42%	4440
	11th to 20th	Day	5% 5% 2 6% 4 4 5% 4 6% 10% 49%	4185
	21st to end	Day	7% 4 2 6% 5% 5% 5% 5% 8% 12% 40%	4465
August	1st to 10th	Day	5% 4 2 5% 4 4 5% 5% 7% 11% 51%	4104
	11th to 20th	Day	11% 6% 2 6% 4 4 5% 4 5% 8% 45%	3918
	21st to end	Day	5% 4 2 5% 4 4 4 4 6% 9% 53%	4180
September	1st to 10th	Day	11% 4 2 4 4 4 4 4 5% 7% 51%	2280
	11th to 20th	Day	11% 5% 2 5% 4 3 4 4 5% 7% 51%	2280
	21st to end	Day	8% 4 2 6% 3 3 5% 3 5% 7% 53%	1981
October	1st to 10th	Day	10% 6% 2 5% 4 3 4 3 4 5% 55%	1900
	11th to 20th	Day	14% 6% 2 5% 3 3 3 2 3 5% 53%	1900
	21st to end	Day	18% 9% 2 5% 3 2 3 2 4 5% 47%	2090
November	1st to 10th	Day	13% 6% 2 4 3 3 3 3 5% 6% 53%	1844
	11th to 20th	Day	14% 7% 2 6% 3 3 3 3 5% 6% 48%	1682
	21st to end	Day	17% 8% 2 5% 4 3 3 3 4 6% 44%	1520
December	1st to 10th	Day	13% 10% 2 6% 5% 3 3 3 5% 6% 44%	1520
	11th to 20th	Day	13% 11% 4 7% 4 4 3 3 4 6% 42%	1918
	21st to end	Day	18% 15% 5% 11% 5% 4 4 3 4 5% 25%	2783
January	1st to 10th	Night	11% 11% 5% 13% 6% 5% 4 3 4 4 36%	4259
	11th to 20th	Night	13% 9% 4 11% 6% 7% 5% 4 4 5% 32%	4120
	21st to end	Night	20% 15% 6% 7% 4 3 3 2 3 4 32%	4532
February	1st to 10th	Night	14% 11% 4 8% 6% 4 4 4 6% 6% 35%	2470
	11th to 20th	Night	13% 8% 3 8% 5% 4 4 3 5% 5% 42%	2361
	21st to end	Night	14% 10% 3 8% 4 3 3 4 4 6% 41%	1884
March	1st to 10th	Night	17% 11% 2 5% 3 3 3 3 3 4 46%	3449
	11th to 20th	Night	13% 6% 2 5% 3 2 4 3 5% 6% 51%	3480
	21st to end	Night	16% 11% 4 8% 5% 5% 4 4 5% 5% 32%	3789
April	1st to 10th	Night	11% 7% 2 6% 3 3 5% 3 4 7% 49%	1900
	11th to 20th	Night	14% 8% 2 5% 4 4 3 3 5% 6% 45%	1875
	21st to end	Night	17% 8% 3 5% 5% 5% 3 4 4 6% 41%	1900
May	1st to 10th	Night	15% 8% 3 6% 4 3 4 4 6% 8% 39%	2892
	11th to 20th	Night	12% 8% 3 6% 5% 4 5% 4 5% 8% 42%	2706
	21st to end	Night	10% 5% 2 5% 4 4 4 3 6% 9% 48%	2743
June	1st to 10th	Night	7% 3 1 5% 4 3 4 5% 6% 10% 51%	1520
	11th to 20th	Night	6% 4 1 5% 4 3 4 4 7% 10% 51%	1520
	21st to end	Night	3 3 1 3 3 4 4 4 7% 10% 58%	1520
July	1st to 10th	Night	11% 5% 2 6% 4 4 4 4 5% 8% 46%	2530
	11th to 20th	Night	4 3 2 4 3 3 4 3 6% 10% 58%	2779
	21st to end	Night	5% 4 2 6% 4 3 4 4 6% 10% 50%	3098
August	1st to 10th	Night	3 3 1 3 3 3 3 3 6% 8% 63%	2836
	11th to 20th	Night	10% 6% 3 6% 3 4 3 3 5% 7% 51%	2915
	21st to end	Night	4 3 1 4 4 3 4 4 6% 8% 59%	3476
September	1st to 10th	Night	11% 4 2 4 2 2 3 3 4 7% 58%	1900
	11th to 20th	Night	9% 5% 2 4 3 3 4 3 6% 7% 53%	1900
	21st to end	Night	8% 5% 2 5% 3 3 4 3 4 6% 56%	2174
October	1st to 10th	Night	8% 4 1 4 3 3 3 3 4 6% 60%	2280
	11th to 20th	Night	12% 5% 2 5% 3 3 4 3 4 5% 53%	2280
	21st to end	Night	16% 7% 2 4 3 3 4 2 4 5% 49%	2508
November	1st to 10th	Night	11% 6% 2 4 2 2 4 2 4 5% 57%	2332
	11th to 20th	Night	12% 7% 3 6% 4 3 3 2 4 5% 50%	2493
	21st to end	Night	16% 8% 2 6% 3 3 3 2 4 5% 47%	2660
December	1st to 10th	Night	12% 12% 4 5% 5% 3 4 4 5% 6% 40%	2660
	11th to 20th	Night	14% 10% 4 7% 4 3 3 3 4 6% 41%	3279
	21st to end	Night	18% 19% 5% 10% 4 4 4 3 4 4 26%	4884

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	49% 4 9% 25% 12% 1	2692
	11th to 20th	Day	50% 7% 9% 22% 13%	2850
	21st to end	Day	54% 4 8% 17% 15% 2	3135
February	1st to 10th	Day	53% 3 10% 20% 13% 1	1710
	11th to 20th	Day	46% 3 12% 21% 14% 3	1713
	21st to end	Day	47% 3 9% 23% 15% 4	1570
March	1st to 10th	Day	44% 2 7% 22% 20% 4	3431
	11th to 20th	Day	35% 4 11% 29% 17% 4	3480
	21st to end	Day	51% 6% 17% 19% 6% 1	3840
April	1st to 10th	Day	41% 4 10% 25% 17% 2	2280
	11th to 20th	Day	44% 4 11% 24% 15% 2	2254
	21st to end	Day	50% 3 11% 21% 13% 1	2280
May	1st to 10th	Day	46% 7% 13% 21% 12% 1	4045
	11th to 20th	Day	44% 6% 12% 25% 13% 1	4200
	21st to end	Day	37% 7% 10% 28% 17% 1	4837
June	1st to 10th	Day	32% 6% 15% 29% 16% 1	2660
	11th to 20th	Day	30% 6% 13% 30% 17% 3	2660
	21st to end	Day	27% 6% 17% 30% 16% 4	2660
July	1st to 10th	Day	41% 5% 11% 25% 16% 2	4371
	11th to 20th	Day	31% 4 13% 33% 17% 2	4113
	21st to end	Day	35% 5% 20% 29% 9% 1	4325
August	1st to 10th	Day	27% 5% 19% 33% 16% 1	4090
	11th to 20th	Day	38% 4 14% 28% 15% 1	3957
	21st to end	Day	28% 4 16% 35% 14% 4	4179
September	1st to 10th	Day	33% 4 10% 28% 19% 6%	2280
	11th to 20th	Day	32% 4 9% 26% 26% 3	2280
	21st to end	Day	30% 5% 8% 28% 25% 4	1981
October	1st to 10th	Day	20% 2 5% 20% 40% 14%	3160
	11th to 20th	Day	23% 2 4 22% 39% 10%	3140
	21st to end	Day	35% 3 8% 25% 28% 2	3428
November	1st to 10th	Day	33% 3 13% 24% 22% 5%	1844
	11th to 20th	Day	38% 2 10% 23% 23% 4	1682
	21st to end	Day	42% 4 8% 30% 15% 2	1520
December	1st to 10th	Day	42% 3 10% 31% 12% 1	1520
	11th to 20th	Day	45% 2 12% 25% 14% 2	1915
	21st to end	Day	61% 5% 9% 16% 9% 1	2783
January	1st to 10th	Night	51% 4 10% 22% 12% 1	4259
	11th to 20th	Night	55% 4 9% 21% 10% 1	4120
	21st to end	Night	57% 3 9% 21% 10% 1	4532
February	1st to 10th	Night	50% 4 10% 21% 13% 2	2470
	11th to 20th	Night	43% 4 11% 21% 17% 3	2362
	21st to end	Night	45% 3 9% 21% 17% 4	1884
March	1st to 10th	Night	44% 4 9% 23% 18% 4	3449
	11th to 20th	Night	34% 5% 9% 25% 24% 4	3480
	21st to end	Night	52% 6% 12% 23% 6% 1	3789
April	1st to 10th	Night	35% 4 10% 27% 20% 4	1900
	11th to 20th	Night	40% 3 9% 24% 17% 6%	1875
	21st to end	Night	44% 4 9% 24% 16% 2	1900
May	1st to 10th	Night	41% 7% 15% 20% 15% 2	2920
	11th to 20th	Night	40% 7% 12% 28% 12% 1	2707
	21st to end	Night	33% 6% 14% 25% 21% 1	2751
June	1st to 10th	Night	28% 6% 16% 31% 16% 4	1520
	11th to 20th	Night	27% 5% 12% 28% 23% 5%	1520
	21st to end	Night	20% 5% 17% 31% 21% 7%	1520
July	1st to 10th	Night	37% 4 11% 28% 17% 3	2490
	11th to 20th	Night	23% 4 11% 40% 20% 2	2728
	21st to end	Night	27% 5% 22% 34% 12% 1	2999
August	1st to 10th	Night	19% 3 21% 31% 23% 2	2826
	11th to 20th	Night	35% 4 12% 29% 18% 3	2942
	21st to end	Night	22% 4 16% 37% 16% 4	3476
September	1st to 10th	Night	28% 3 11% 25% 26% 7%	1900
	11th to 20th	Night	30% 4 9% 25% 26% 5%	1900
	21st to end	Night	30% 3 7% 28% 28% 4	2174
October	1st to 10th	Night	16% 2 5% 21% 44% 11%	3800
	11th to 20th	Night	23% 2 7% 21% 31% 16%	3779
	21st to end	Night	35% 3 6% 29% 25% 3	4120
November	1st to 10th	Night	31% 4 11% 28% 20% 6%	2332
	11th to 20th	Night	37% 2 6% 26% 24% 5%	2493
	21st to end	Night	41% 3 10% 26% 17% 3	2660
December	1st to 10th	Night	45% 4 11% 25% 14% 1	2660
	11th to 20th	Night	45% 3 9% 28% 14% 1	3281
	21st to end	Night	62% 4 9% 15% 8% 2	4884

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
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	24% 15% 36% 19% 5%	270
	11th to 20th	Day	33% 14% 39% 14% 1	270
	21st to end	Day	21% 16% 42% 16% 4	297
February	1st to 10th	Day	26% 14% 43% 14% 3	270
	11th to 20th	Day	25% 23% 34% 13% 6%	270
	21st to end	Day	30% 18% 40% 10% 3	225
March	1st to 10th	Day	19% 17% 48% 14% 1	270
	11th to 20th	Day	29% 13% 35% 20% 3 1	270
	21st to end	Day	35% 18% 29% 14% 5%	311
April	1st to 10th	Day	21% 15% 33% 24% 6% 1	460
	11th to 20th	Day	24% 14% 33% 20% 8%	452
	21st to end	Day	28% 11% 31% 22% 7% 1	460
May	1st to 10th	Day	21% 11% 32% 24% 11% 1	604
	11th to 20th	Day	21% 7% 24% 28% 17% 3	675
	21st to end	Day	17% 4 28% 27% 16% 7%	734
June	1st to 10th	Day	9% 3 17% 35% 27% 9%	680
	11th to 20th	Day	9% 2 21% 40% 23% 5%	680
	21st to end	Day	6% 4 29% 35% 19% 6%	680
July	1st to 10th	Day	13% 2 10% 31% 30% 14%	671
	11th to 20th	Day	6% 2 18% 37% 28% 9%	668
	21st to end	Day	10% 1 13% 32% 32% 11%	739
August	1st to 10th	Day	10% 1 15% 38% 28% 9%	676
	11th to 20th	Day	12% 2 16% 36% 27% 8%	594
	21st to end	Day	9% 1 10% 31% 35% 13%	539
September	1st to 10th	Day	12% 1 12% 33% 33% 9%	490
	11th to 20th	Day	9% 1 17% 33% 29% 11%	490
	21st to end	Day	9% 8% 27% 31% 18% 7%	305
October	1st to 10th	Day	15% 4 28% 30% 18% 5%	300
	11th to 20th	Day	18% 17% 31% 25% 8% 1	300
	21st to end	Day	29% 17% 29% 22% 3 1	330
November	1st to 10th	Day	20% 7% 39% 22% 10% 3	282
	11th to 20th	Day	22% 15% 28% 26% 8% 1	270
	21st to end	Day	28% 15% 26% 27% 4 1	270
December	1st to 10th	Day	17% 16% 41% 16% 9% 1	270
	11th to 20th	Day	22% 17% 37% 20% 4	270
	21st to end	Day	26% 18% 38% 16% 2	297
January	1st to 10th	Night	16% 16% 36% 26% 5%	950
	11th to 20th	Night	22% 16% 36% 21% 5%	950
	21st to end	Night	19% 13% 38% 27% 2	1045
February	1st to 10th	Night	21% 15% 37% 24% 4	950
	11th to 20th	Night	20% 15% 37% 24% 3	887
	21st to end	Night	24% 15% 39% 19% 3	628
March	1st to 10th	Night	21% 14% 37% 23% 4	589
	11th to 20th	Night	25% 9% 31% 29% 5%	570
	21st to end	Night	27% 11% 33% 23% 5%	627
April	1st to 10th	Night	17% 12% 34% 31% 5%	570
	11th to 20th	Night	20% 11% 32% 29% 8%	563
	21st to end	Night	20% 6% 38% 27% 9%	570
May	1st to 10th	Night	17% 5% 31% 36% 10% 1	570
	11th to 20th	Night	16% 3 25% 38% 17% 1	561
	21st to end	Night	14% 3 25% 33% 23% 2	617
June	1st to 10th	Night	10% 1 17% 41% 28% 3	570
	11th to 20th	Night	8% 1 20% 45% 24% 2	570
	21st to end	Night	5% 2 21% 49% 21% 2	570
July	1st to 10th	Night	10% 9% 38% 37% 6%	555
	11th to 20th	Night	5% 1 12% 43% 35% 3	552
	21st to end	Night	8% 1 12% 41% 35% 3	624
August	1st to 10th	Night	7% 1 11% 44% 34% 3	567
	11th to 20th	Night	8% 1 12% 46% 29% 4	564
	21st to end	Night	7% 1 10% 36% 42% 4	627
September	1st to 10th	Night	13% 1 12% 38% 31% 6%	570
	11th to 20th	Night	10% 2 12% 38% 32% 6%	570
	21st to end	Night	11% 3 22% 36% 25% 3	664
October	1st to 10th	Night	9% 4 26% 34% 23% 3	760
	11th to 20th	Night	15% 9% 35% 30% 10%	760
	21st to end	Night	21% 10% 32% 28% 8%	836
November	1st to 10th	Night	15% 9% 34% 32% 11%	760
	11th to 20th	Night	18% 12% 33% 29% 8%	783
	21st to end	Night	21% 10% 37% 26% 6%	950
December	1st to 10th	Night	21% 12% 35% 25% 7% 1	950
	11th to 20th	Night	22% 9% 34% 29% 5%	950
	21st to end	Night	24% 14% 33% 26% 3	1045

Page generated at 2024-11-03 01:11:28. Version ac07

Copyright © 2024 Attilla Danko.