make an arc to Arcturus, and speak to Spica

By: superfalke , 6:17 AM GMT on February 21, 2010

Share this Blog
0
+

Beautiful winter sky around midnight, with the moon low in the sky.

Using "Yesterday's Official Weather and Almanac", and looking at the data below, i have to wonder:
What sort of math takes (-5), adds (2), and averages the result to arrive at (0)? That is, to get 26 heating degree days for both Actual and Average.

Roanoke data for 2/19/10:

...........Actual.....Avg.....Record
Max Temp.....45.....50.....77 (1939)
Min Temp.....32.....30......7 (1979)

Heating Degree Days:
.............26.....26

Since 7/1/09 heating degree days:
...........3112.....3086 (how about that, 26 hdd above normal)

Here's the explanation.
When rounding off, if you're exactly in the middle, then round off to the even number. Also, in this case, compute the contributions from MIN and MAX temps separately. For example, the actual MIN was 32, so its contribution to total heating degree days = (65 - 32)/2 = 16.5 which rounds down to 16.

Actual MIN (20/2) = 10
Actual MAX (33/2) = 16.5 ==> 16
HDD = 10 + 16 = 26

Average MIN (15/2) = 7.5 ==> 8
Average MAX (35/2) = 17.5 ==> 18
HDD = 8 + 18 = 26

=====================================================

Looks like we've got a horse race this year anyway. Could be the first time in a long time to have a colder than normal heating season. Need to break 4284 hdd to make it happen here in Roanoke VA.





Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1 - 1

Page: 1 — Blog Index

1. unclemush
7:02 AM GMT on February 21, 2010
Nice pictures! :)
Member Since: July 7, 2001 Posts: 59 Comments: 13166

Viewing: 1 - 1

Page: 1 — Blog Index

Top of Page

About superfalke

Superfalke was a Scheibe motorglider that flew from San Diego to New Castle VA in 1983.

Local Weather

Overcast
39 °F
Overcast

superfalke's Recent Photos

Fog in the valley-1
Fog in the valley-2
Fog in the valley-3
Fog in the valley-4

Personal Weather Stations

Coopers Cove at Lakeshore Terrace
Hardy, VA
Elevation: 912 ft
Temperature: 39.5 °F
Dew Point: 32.6 °F
Humidity: 76%
Wind: 2.0 mph from the NNE
Wind Gust: 4.0 mph
Updated: 12:44 AM EST on December 22, 2014

About Personal Weather Stations