Kansas City
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kansas City clear sky chart from 2005-11-05 to 2009-12-29.

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	14% 6% 5% 5% 5% 7% 39%	16435
	Night	12% 6% 7% 45%	16524
Transparency	Day	18% 29% 15%	13113
	Night	17% 30% 18%	13611
Seeing	Day	6% 26% 32% 18%	1018
	Night	12% 34% 30% 9%	5227

By Month

Percentage Cloud Cover
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month		Occurrence of each Forecast	Data Points
January	Day	12% 6% 5% 5% 6% 44%	1102
	Night	9% 5% 8% 48%	1596
February	Day	10% 10% 6% 6% 6% 6% 36%	1022
	Night	11% 7% 5% 6% 42%	1376
March	Day	18% 8% 5% 7% 5% 6% 8% 28%	1363
	Night	16% 6% 5% 5% 7% 39%	1362
April	Day	21% 9% 5% 5% 36%	1427
	Night	17% 6% 5% 47%	1175
May	Day	16% 6% 5% 5% 6% 6% 34%	1615
	Night	11% 5% 5% 6% 5% 5% 5% 8% 41%	1082
June	Day	10% 7% 5% 8% 9% 40%	1671
	Night	8% 5% 6% 11% 49%	959
July	Day	8% 5% 6% 5% 6% 5% 10% 41%	1600
	Night	6% 5% 5% 7% 10% 46%	1090
August	Day	10% 5% 6% 10% 45%	1566
	Night	6% 5% 5% 5% 9% 50%	1148
September	Day	12% 5% 5% 5% 5% 6% 6% 40%	1346
	Night	10% 5% 7% 47%	1254
October	Day	21% 6% 5% 5% 43%	1222
	Night	18% 5% 48%	1471
November	Day	15% 6% 6% 48%	1271
	Night	13% 6% 6% 51%	1896
December	Day	14% 10% 6% 5% 5% 7% 34%	1230
	Night	16% 9% 5% 6% 35%	2115

Transparency (when cloud cover <= 30%)
Color Meanings: Poor Below Average Average Above average Transparent
Month		Occurrence of each Forecast	Data Points
January	Day	21% 31% 15%	848
	Night	17% 34% 21%	1301
February	Day	26% 29% 7%	805
	Night	20% 32% 14%	1079
March	Day	23% 25% 8%	957
	Night	20% 28% 15%	1059
April	Day	13% 28% 17%	1121
	Night	10% 30% 25%	972
May	Day	6% 17% 25% 16%	1190
	Night	5% 20% 23% 21%	855
June	Day	5% 21% 34% 14%	1334
	Night	25% 30% 18%	832
July	Day	19% 31% 13%	1131
	Night	16% 34% 17%	788
August	Day	15% 29% 20%	1369
	Night	14% 31% 26%	995
September	Day	11% 26% 18%	1209
	Night	12% 28% 22%	1131
October	Day	12% 25% 20%	1086
	Night	10% 24% 23% 6%	1307
November	Day	17% 34% 17%	1070
	Night	17% 35% 17%	1580
December	Day	21% 28% 6%	993
	Night	20% 29% 8%	1712

Seeing (when cloud cover <= 80%)
Color Meanings: Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month		Occurrence of each Forecast	Data Points
January	Night	20% 49% 21%	589
February	Night	17% 45% 24%	468
March	Night	16% 37% 26% 5%	345
April	Day	10% 37% 28% 5%	114
	Night	14% 35% 32%	332
May	Day	10% 35% 27% 11%	229
	Night	6% 34% 36% 10%	355
June	Day	7% 32% 30% 18%	220
	Night	23% 47% 16%	331
July	Day	22% 40% 23%	210
	Night	17% 48% 23%	320
August	Day	14% 35% 28% 7%	203
	Night	18% 42% 28%	352
September	Day	7% 30% 21% 19%	42
	Night	15% 32% 26% 7%	339
October	Night	14% 34% 24% 8%	459
November	Night	12% 41% 26% 6%	632
December	Night	16% 38% 24%	705

Page generated at 2009-12-30 04:20:36. Version ab11