06 January 2007

Is it warm outside or is it me?

This
Afternoon

Partly
Cloudy
Hi 21°C

It is warm outside. The National Weather Service (NWS) had predicted that today the temperature would go up to 21ºC (70ºF) and the last time I checked about an hour ago, it was reported as 21ºC.

According to the NWS summary for December 2006, the average monthly temperature in the Washington D.C. area of 44.2ºF ties it with 1994 as the 10th warmest December on record. The chart below is from the NWS.


You will notice that the 4th column gives the "normal" values. Back in November of last year, Duane at Abnormal Interests had an abnormal criticism of the use of the term "normal" to mean "average" by a local weatherperson. I agreed with Duane back then. But, it turns out that the NWS is also using the term normal in addition to average (and also mean). If I understand it correctly, they use average and mean to denote monthly values and "normal" to denote the average over a longer period (1971-2000).

So far we have had none of that white fluffy stuff that is supposed to fall down from the sky in the winter either.

2 comments:

Duane said...

Interesting. I need to think about this. I'd like to see a precise "weather" definition of both normal and average. The average maximum (or minimum) normal value is interesting as is the mean normal value. They kind of put pressure on the brain. As a minimum abnormal observation, I'd say that one of our local weather reporters uses different terminology than all the others and that is at best confusing. But now I'm a little confused about which who is correct, if anyone.

Roger B. said...

There's no sign of snow on this side of the Atlantic either!