TAS-D Atoka
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the TAS-D Atoka clear sky chart from 2005-11-06 to 2024-05-13.

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 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% 6% 2 5% 4 4 4 3 5% 6% 49%	84042
	Night	12% 5% 2 4 3 3 3 3 5% 6% 54%	85524
Transparency	Day	35% 5% 11% 22% 21% 5%	83767
	Night	31% 5% 10% 23% 24% 8%	85319
Seeing	Day	13% 9% 24% 28% 20% 6%	14547
	Night	13% 9% 28% 33% 16% 1	24557

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% 8% 4 6% 3 3 2 2 4 5% 49%	2847
	11th to 20th	Day	9% 6% 1 4 2 3 3 2 3 4 64%	2850
	21st to end	Day	20% 10% 3 6% 3 2 2 2 3 4 45%	3135
February	1st to 10th	Day	18% 7% 3 6% 4 3 4 3 3 5% 44%	1728
	11th to 20th	Day	16% 7% 3 5% 4 4 3 2 4 6% 46%	1849
	21st to end	Day	22% 7% 3 5% 3 2 2 3 4 4 45%	1622
March	1st to 10th	Day	16% 7% 2 5% 4 3 3 3 4 5% 48%	3436
	11th to 20th	Day	15% 8% 2 6% 4 4 4 4 4 6% 43%	3480
	21st to end	Day	18% 9% 2 6% 5% 4 4 3 5% 5% 40%	3814
April	1st to 10th	Day	13% 7% 2 6% 4 3 4 4 4 6% 48%	2090
	11th to 20th	Day	15% 5% 2 6% 5% 3 4 3 5% 7% 45%	2225
	21st to end	Day	15% 7% 2 7% 4 4 5% 3 5% 6% 42%	2389
May	1st to 10th	Day	15% 7% 3 5% 5% 3 4 3 5% 7% 44%	2470
	11th to 20th	Day	14% 7% 2 6% 5% 4 5% 4 5% 6% 42%	2330
	21st to end	Day	11% 7% 2 6% 6% 6% 5% 4 6% 7% 39%	2531
June	1st to 10th	Day	7% 6% 2 6% 5% 4 5% 4 6% 9% 46%	2340
	11th to 20th	Day	7% 4 2 4 4 5% 5% 4 7% 10% 47%	2340
	21st to end	Day	4 4 1 4 4 4 5% 5% 7% 8% 55%	2340
July	1st to 10th	Day	6% 5% 2 6% 6% 5% 5% 6% 8% 10% 42%	2340
	11th to 20th	Day	3 2 1 3 4 4 5% 5% 6% 9% 58%	2340
	21st to end	Day	5% 3 2 5% 5% 5% 5% 4 8% 10% 49%	2546
August	1st to 10th	Day	3 3 1 4 3 5% 5% 5% 6% 9% 55%	2328
	11th to 20th	Day	8% 4 2 5% 4 4 5% 4 7% 8% 49%	2301
	21st to end	Day	3 3 1 4 5% 5% 5% 5% 8% 11% 50%	2410
September	1st to 10th	Day	10% 4 2 4 4 3 4 3 6% 6% 54%	1980
	11th to 20th	Day	10% 4 3 5% 4 4 5% 4 5% 6% 48%	1980
	21st to end	Day	7% 3 1 4 3 3 4 3 4 7% 59%	1980
October	1st to 10th	Day	7% 4 1 5% 4 4 4 4 5% 6% 57%	1885
	11th to 20th	Day	12% 5% 2 4 3 2 2 2 3 4 62%	1800
	21st to end	Day	18% 5% 1 4 3 2 2 2 3 4 54%	1980
November	1st to 10th	Day	12% 5% 2 6% 2 3 3 3 5% 5% 54%	1858
	11th to 20th	Day	10% 4 2 4 2 2 3 3 3 5% 61%	1782
	21st to end	Day	18% 5% 2 3 3 2 4 2 3 5% 53%	1710
December	1st to 10th	Day	14% 6% 2 5% 2 2 2 3 5% 6% 52%	1710
	11th to 20th	Day	17% 8% 2 4 3 4 4 3 4 4 46%	2161
	21st to end	Day	21% 7% 2 4 3 3 3 3 4 6% 45%	3135
January	1st to 10th	Night	13% 8% 2 5% 3 3 3 3 4 5% 52%	4108
	11th to 20th	Night	9% 5% 2 4 3 3 2 2 4 5% 62%	4120
	21st to end	Night	22% 7% 2 4 3 2 3 2 3 4 47%	4532
February	1st to 10th	Night	15% 7% 2 6% 3 3 3 3 5% 4 48%	2469
	11th to 20th	Night	15% 8% 2 5% 3 3 3 2 4 6% 48%	2218
	21st to end	Night	16% 7% 2 5% 3 3 3 2 4 4 51%	1831
March	1st to 10th	Night	17% 8% 2 6% 3 3 3 3 5% 5% 44%	3419
	11th to 20th	Night	12% 6% 2 5% 3 3 3 3 4 5% 54%	3480
	21st to end	Night	15% 7% 2 5% 3 3 4 4 5% 6% 46%	3817
April	1st to 10th	Night	11% 5% 2 6% 4 4 3 2 4 6% 52%	2090
	11th to 20th	Night	13% 5% 2 5% 3 3 3 3 5% 7% 51%	1903
	21st to end	Night	15% 5% 1 4 4 3 3 3 5% 7% 50%	1786
May	1st to 10th	Night	12% 5% 2 5% 4 3 4 4 5% 7% 48%	1710
	11th to 20th	Night	12% 5% 2 4 4 4 5% 3 5% 8% 49%	1620
	21st to end	Night	7% 5% 2 6% 3 4 4 5% 6% 9% 49%	1745
June	1st to 10th	Night	4 4 1 4 3 4 4 4 6% 8% 59%	1620
	11th to 20th	Night	4 4 1 4 2 3 3 3 6% 9% 60%	1620
	21st to end	Night	2 3 1 3 2 3 4 3 5% 8% 65%	1620
July	1st to 10th	Night	4 4 1 3 5% 4 4 5% 7% 11% 52%	1620
	11th to 20th	Night	3 1 1 2 2 2 2 4 6% 11% 66%	1620
	21st to end	Night	2 2 1 3 3 3 3 5% 8% 10% 60%	1772
August	1st to 10th	Night	2 2 1 2 3 3 4 5% 6% 8% 62%	1611
	11th to 20th	Night	4 3 1 4 3 3 4 4 6% 11% 57%	1600
	21st to end	Night	3 3 1 4 4 4 4 4 6% 9% 58%	1939
September	1st to 10th	Night	7% 4 1 4 2 3 3 3 5% 7% 61%	1980
	11th to 20th	Night	9% 4 2 5% 4 4 4 3 6% 6% 52%	1980
	21st to end	Night	7% 3 2 3 2 3 3 2 4 7% 64%	1980
October	1st to 10th	Night	8% 4 2 4 3 3 3 3 4 5% 61%	2056
	11th to 20th	Night	12% 5% 1 3 2 2 2 2 3 5% 61%	2160
	21st to end	Night	17% 4 1 4 2 2 2 2 3 4 58%	2376
November	1st to 10th	Night	11% 4 1 4 3 3 3 2 4 5% 59%	2220
	11th to 20th	Night	9% 5% 2 5% 3 3 3 3 4 6% 59%	2394
	21st to end	Night	16% 6% 2 3 3 2 3 3 4 6% 53%	2470
December	1st to 10th	Night	14% 5% 2 4 2 2 3 3 5% 6% 54%	2470
	11th to 20th	Night	14% 6% 3 5% 4 3 3 2 4 5% 50%	3036
	21st to end	Night	18% 8% 2 5% 3 2 3 2 3 5% 51%	4532

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	38% 3 8% 22% 24% 4	2848
	11th to 20th	Day	27% 3 12% 23% 31% 5%	2850
	21st to end	Day	45% 3 4 19% 23% 7%	3135
February	1st to 10th	Day	44% 4 9% 17% 21% 5%	1728
	11th to 20th	Day	42% 4 7% 22% 19% 6%	1859
	21st to end	Day	44% 3 5% 14% 25% 9%	1622
March	1st to 10th	Day	39% 4 8% 14% 23% 11%	3436
	11th to 20th	Day	42% 6% 10% 22% 17% 4	3480
	21st to end	Day	46% 6% 8% 21% 17% 3	3814
April	1st to 10th	Day	39% 4 10% 21% 18% 9%	2090
	11th to 20th	Day	39% 6% 10% 20% 19% 6%	2225
	21st to end	Day	42% 5% 9% 20% 19% 4	2389
May	1st to 10th	Day	40% 6% 11% 22% 18% 4	2470
	11th to 20th	Day	41% 8% 12% 23% 16% 1	2334
	21st to end	Day	43% 8% 13% 20% 15% 1	2531
June	1st to 10th	Day	33% 7% 15% 27% 15% 2	2340
	11th to 20th	Day	32% 8% 13% 27% 18% 2	2340
	21st to end	Day	25% 8% 13% 27% 24% 3	2340
July	1st to 10th	Day	34% 11% 19% 23% 13% 1	2276
	11th to 20th	Day	20% 7% 16% 31% 22% 4	2271
	21st to end	Day	25% 9% 18% 33% 16%	2405
August	1st to 10th	Day	21% 9% 16% 29% 23% 2	2314
	11th to 20th	Day	30% 8% 14% 26% 20% 3	2301
	21st to end	Day	26% 9% 17% 27% 16% 4	2410
September	1st to 10th	Day	29% 5% 12% 24% 20% 10%	1980
	11th to 20th	Day	34% 8% 11% 20% 20% 7%	1980
	21st to end	Day	26% 5% 9% 21% 29% 9%	1980
October	1st to 10th	Day	28% 5% 12% 20% 22% 13%	1885
	11th to 20th	Day	29% 3 6% 16% 30% 15%	1800
	21st to end	Day	36% 3 7% 18% 25% 11%	1980
November	1st to 10th	Day	33% 3 9% 23% 25% 7%	1858
	11th to 20th	Day	27% 3 9% 23% 29% 10%	1782
	21st to end	Day	35% 3 6% 19% 27% 9%	1710
December	1st to 10th	Day	34% 4 9% 28% 21% 5%	1710
	11th to 20th	Day	42% 4 5% 19% 23% 7%	2159
	21st to end	Day	41% 3 7% 22% 23% 5%	3135
January	1st to 10th	Night	35% 3 7% 20% 30% 6%	4108
	11th to 20th	Night	25% 4 12% 24% 28% 7%	4120
	21st to end	Night	42% 3 7% 17% 24% 7%	4532
February	1st to 10th	Night	40% 4 9% 19% 21% 7%	2469
	11th to 20th	Night	38% 4 7% 20% 23% 7%	2218
	21st to end	Night	38% 4 6% 17% 22% 13%	1831
March	1st to 10th	Night	42% 4 7% 16% 18% 13%	3419
	11th to 20th	Night	35% 4 8% 28% 16% 9%	3480
	21st to end	Night	39% 5% 10% 19% 25% 3	3817
April	1st to 10th	Night	34% 4 10% 19% 20% 13%	2090
	11th to 20th	Night	34% 5% 9% 21% 19% 12%	1903
	21st to end	Night	34% 5% 10% 24% 22% 4	1786
May	1st to 10th	Night	36% 6% 10% 21% 18% 8%	1710
	11th to 20th	Night	34% 6% 14% 26% 17% 2	1621
	21st to end	Night	30% 8% 16% 26% 16% 3	1746
June	1st to 10th	Night	22% 7% 15% 31% 21% 3	1620
	11th to 20th	Night	20% 6% 13% 33% 23% 5%	1620
	21st to end	Night	17% 6% 13% 28% 30% 6%	1620
July	1st to 10th	Night	24% 8% 17% 29% 19% 3	1575
	11th to 20th	Night	12% 5% 16% 36% 27% 5%	1566
	21st to end	Night	18% 7% 15% 34% 26% 1	1673
August	1st to 10th	Night	16% 6% 13% 34% 25% 5%	1601
	11th to 20th	Night	22% 5% 13% 29% 25% 5%	1600
	21st to end	Night	22% 7% 16% 30% 20% 5%	1939
September	1st to 10th	Night	23% 6% 11% 23% 27% 9%	1980
	11th to 20th	Night	31% 6% 10% 20% 21% 11%	1980
	21st to end	Night	21% 4 8% 25% 29% 13%	1980
October	1st to 10th	Night	25% 5% 10% 22% 23% 16%	2056
	11th to 20th	Night	27% 3 7% 14% 29% 19%	2160
	21st to end	Night	32% 3 5% 20% 26% 14%	2376
November	1st to 10th	Night	29% 3 8% 23% 26% 12%	2220
	11th to 20th	Night	27% 4 7% 22% 27% 12%	2394
	21st to end	Night	34% 3 7% 19% 28% 8%	2470
December	1st to 10th	Night	32% 4 10% 23% 22% 9%	2470
	11th to 20th	Night	38% 3 6% 16% 28% 9%	3037
	21st to end	Night	38% 3 7% 22% 23% 8%	4532

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	21% 17% 33% 24% 5%	270
	11th to 20th	Day	20% 20% 35% 20% 4 1	270
	21st to end	Day	19% 19% 33% 20% 9% 1	297
February	1st to 10th	Day	25% 17% 34% 19% 4	270
	11th to 20th	Day	24% 20% 36% 17% 3	270
	21st to end	Day	30% 17% 40% 10% 3	225
March	1st to 10th	Day	22% 19% 35% 19% 6%	270
	11th to 20th	Day	24% 24% 32% 13% 4 2	270
	21st to end	Day	22% 16% 41% 16% 4	297
April	1st to 10th	Day	20% 21% 34% 20% 5%	270
	11th to 20th	Day	22% 18% 32% 23% 5%	423
	21st to end	Day	18% 17% 36% 23% 5% 2	569
May	1st to 10th	Day	15% 11% 38% 28% 7%	653
	11th to 20th	Day	16% 8% 32% 28% 14% 3	637
	21st to end	Day	12% 8% 31% 28% 16% 5%	679
June	1st to 10th	Day	8% 3 18% 37% 26% 9%	630
	11th to 20th	Day	8% 3 20% 38% 26% 6%	630
	21st to end	Day	4 2 17% 36% 30% 11%	630
July	1st to 10th	Day	5% 1 11% 34% 34% 15%	621
	11th to 20th	Day	2 1 7% 33% 43% 12%	618
	21st to end	Day	3 1 6% 33% 40% 17%	684
August	1st to 10th	Day	4 1 10% 33% 42% 10%	626
	11th to 20th	Day	8% 3 10% 36% 36% 7%	615
	21st to end	Day	5% 1 5% 30% 42% 17%	529
September	1st to 10th	Day	6% 1 7% 28% 37% 21%	270
	11th to 20th	Day	6% 3 7% 32% 36% 16%	270
	21st to end	Day	13% 4 13% 34% 26% 11%	270
October	1st to 10th	Day	4 4 27% 30% 27% 9%	270
	11th to 20th	Day	16% 10% 27% 28% 18% 1	270
	21st to end	Day	28% 11% 25% 20% 15% 1	297
November	1st to 10th	Day	16% 9% 37% 23% 12% 2	270
	11th to 20th	Day	14% 14% 34% 24% 10% 3	270
	21st to end	Day	24% 13% 30% 22% 9% 1	270
December	1st to 10th	Day	15% 15% 35% 25% 9%	270
	11th to 20th	Day	26% 10% 36% 23% 6%	270
	21st to end	Day	21% 19% 33% 22% 4	297
January	1st to 10th	Night	15% 15% 34% 29% 8%	950
	11th to 20th	Night	18% 17% 33% 27% 6%	950
	21st to end	Night	16% 11% 36% 30% 6%	1045
February	1st to 10th	Night	18% 18% 34% 27% 3	949
	11th to 20th	Night	21% 14% 38% 25% 3	744
	21st to end	Night	22% 16% 40% 19% 3	575
March	1st to 10th	Night	19% 13% 36% 28% 5%	570
	11th to 20th	Night	18% 12% 37% 27% 5%	570
	21st to end	Night	18% 12% 39% 25% 5% 1	627
April	1st to 10th	Night	13% 15% 40% 27% 4	570
	11th to 20th	Night	16% 14% 38% 26% 7%	563
	21st to end	Night	16% 11% 37% 27% 8% 1	570
May	1st to 10th	Night	13% 7% 37% 35% 8%	570
	11th to 20th	Night	13% 6% 33% 33% 14% 1	540
	21st to end	Night	7% 3 32% 37% 19% 2	584
June	1st to 10th	Night	5% 3 17% 41% 29% 4	540
	11th to 20th	Night	5% 1 20% 54% 18% 1	540
	21st to end	Night	2 1 14% 49% 30% 5%	540
July	1st to 10th	Night	5% 1 8% 41% 40% 5%	525
	11th to 20th	Night	3 1 9% 44% 40% 4	522
	21st to end	Night	2 1 6% 45% 41% 5%	591
August	1st to 10th	Night	2 7% 50% 39% 3	537
	11th to 20th	Night	6% 9% 42% 38% 4	534
	21st to end	Night	4 1 5% 43% 42% 5%	594
September	1st to 10th	Night	7% 1 10% 38% 39% 4	540
	11th to 20th	Night	10% 2 13% 36% 35% 3	540
	21st to end	Night	7% 1 18% 38% 33% 2	540
October	1st to 10th	Night	10% 3 20% 41% 23% 3	616
	11th to 20th	Night	15% 6% 29% 34% 15% 1	720
	21st to end	Night	19% 9% 29% 30% 13% 1	792
November	1st to 10th	Night	13% 6% 33% 36% 11% 1	740
	11th to 20th	Night	12% 12% 31% 34% 11%	874
	21st to end	Night	19% 11% 32% 27% 10%	950
December	1st to 10th	Night	17% 12% 33% 31% 7%	950
	11th to 20th	Night	21% 9% 35% 29% 6%	950
	21st to end	Night	20% 12% 36% 27% 6%	1045

Page generated at 2024-05-10 11:39:00. Version ac07

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