Ladyandtramp.com: NWS Digital Forecast Cloud Cover Plot

NWS Digital Forecast Cloud Cover Plot

Amateur astronomers pay attention to the sky and how clear it is. Years ago, we all waited until the evening news to look at the 15 second glance at the satellite image to decide if we should drive out to dark skies to view the stars or not. Today, not only can you get satellite images online in 80 zillion different ways, but you can now also get forecasts for sky cover.

This uses Experimental NWS digital forecast data for sky cover for a 5x5km "grid" of space. Use at your own risk (or fun). Subject to change at any time. Generally, NWS updates the data every hour, but different forecast offices around the county update as often as every three hours or as little as twice a day.

Click on the link above each plot to see these data plotted in a different way. These data are updated 35 minutes past the hour. These CSC like displays are made with apologies to Clear Sky Clock creator Attilla Danko! You are welcome to make comments to bbunge@ladyandtramp.com.

Laurel Highland Star Cruise

Cloud Cover 32 49 84 92 96 92 87 79 64 58 83 85 90 95 100 100 100 92 90 82 82 59 59 78 100 100 95 95 86 84 97 97 76 74 76 76 75
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Tuckahoe State Park (MD)

Cloud Cover 4 21 39 53 65 70 76 77 80 77 75 80 84 92 100 100 100 97 94 93 93 72 59 61 63 87 80 69 63 69 65 60 72 71 70 70 71
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Bowie, MD

Cloud Cover 10 19 49 72 72 82 63 71 82 83 85 89 93 96 99 97 95 93 92 76 60 77 53 62 70 85 99 94 89 69 50 61 72 71 70 72 74
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
CM Crockett Park, VA

Cloud Cover 13 25 52 76 76 84 73 78 83 86 89 92 96 97 98 96 94 93 91 73 56 64 34 48 62 78 93 92 91 73 54 65 75 72 68 71 74
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Spruce Knob (Gatewood)

Cloud Cover 24 78 95 99 100 100 100 100 89 91 92 94 96 96 96 93 90 90 91 80 69 69 48 71 95 95 95 93 90 89 87 81 73 81 87 81 74
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Spruce Knob (TMI)

Cloud Cover 25 69 93 94 100 100 100 100 89 90 92 94 95 96 96 94 91 91 90 80 70 69 48 72 96 96 96 93 90 89 87 81 73 81 88 81 74
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Cherry Springs State Park (PA)

Cloud Cover 7 23 39 66 93 96 100 76 52 39 39 45 50 69 87 92 96 97 98 99 87 65 64 69 73 75 76 78 79 78 74 70 65 68 84 80 100
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Sky Meadows State Park (VA)

Cloud Cover 14 33 76 91 86 92 84 87 81 84 87 92 96 97 98 96 93 92 91 76 61 67 37 51 65 81 97 94 90 70 51 63 75 73 70 70 71
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Southern Park (MD)

Cloud Cover 9 15 43 62 62 73 59 62 81 84 88 92 96 97 98 97 95 93 91 80 68 74 51 52 53 71 89 85 80 66 51 58 64 63 62 69 75
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Oregon Star Party

Cloud Cover 66 66 58 58 36 36 25 25 14 14 14 14 8 8 8 8 15 15 15 15 0 0 18 18 22 22 23 23 29 29 47 47 63 63 53 53 71
Hour (Eastern) 05 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 23 05 11 17 23 05 11 17 23 05 11 17 23 05 11 17 18
Day Wed Thu Fri Sat Sun Mon Tue
Pasco, WA

Cloud Cover 52 52 44 44 25 25 14 14 4 4 4 4 4 4 4 4 4 4 4 4 0 0 5 5 5 5 5 5 16 16 29 29 41 41 35 35 39
Hour (Eastern) 05 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 23 05 11 17 23 05 11 17 23 05 11 17 23 05 11 17 18
Day Wed Thu Fri Sat Sun Mon Tue
Greenbank Radio Observatory (WV)

Cloud Cover 29 53 86 86 83 75 83 82 81 86 90 95 100 100 100 98 96 95 94 78 62 68 59 80 97 90 82 84 84 85 90 85 74 77 83 79 74
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue
Coinjock, NC

Cloud Cover 0 5 10 21 32 37 42 42 42 59 76 80 84 92 100 100 100 94 88 88 88 93 93 67 41 38 36 52 69 73 76 73 69 68 68 58 48
Hour (Eastern) 08 11 14 17 20 23 02 05 08 11 14 17 20 23 02 05 08 11 14 17 20 02 08 14 20 02 08 14 20 02 08 14 20 02 08 14 20 18
Day Wed Thu Fri Sat Sun Mon Tue

Clear Overcast

This data is retrieved from NWS using their National Digital Forecast Database via a XML web service

There are differences between this data and the Clear Sky Clock (CSC). Where CSC goes out about 48 hours, this forecasts out seven days, keeping in mind that forecasts are less accurate the farther out they are. The CSC data is specifically designed for astronomical purposes, the NWS data isn't. The CSC data is a computer model. These are forecasts generated by a human who might be using model, other data and experience as input. NWS forecasters are forecasting percentage of cloud cover. Thin clouds or haze can quickly add up and as a result, it's rare to see percentages less then 15. My personally experience is percentages less then 30 percent are usually good enough for most casual astronomical observing.

Back toBob's Homepage.

bbunge@ladyandtramp.com

status

Cloud Cover	32	49	84	92	96	92	87	79	64	58	83	85	90	95	100	100	100	92	90	82	82	59	59	78	100	100	95	95	86	84	97	97	76	74	76	76	75
Hour (Eastern)	08	11	14	17	20	23	02	05	08	11	14	17	20	23	02	05	08	11	14	17	20	02	08	14	20	02	08	14	20	02	08	14	20	02	08	14	20	18
Day	Wed								Thu								Fri								Sat				Sun				Mon				Tue