Transcript DataStreme Atmos -- Virtual tour of AOS

What’s Normal?
26-29 June 2011
Edward J. Hopkins,
Assistant Wisconsin State Climatologist
Dept. of Atmospheric & Oceanic Sciences
University of Wisconsin-Madison
2011 Summer AERA Training
1
Background

“Normals”
– Way of depicting an expected climate state based upon
statistics over a long-time span.

What normals include:
– Averages
– Frequencies
– Percentiles

Standardized International Agreement
– National Weather Service and National Climatic Data
Center following international agreement to update the
30-year “normals” every ten years.
2011 Summer AERA Training
2
Background (con’t.)

Why 30-year time length?
–
–
–
–

Climate is always changing!
Three-decade time-span deemed appropriate
Not too long to cover-up long-term changes in climate
Not too short for an uneven set of statistics due to yearto-year or decadal changes in weather & climate.
Current climate normal interval covers
1971-2000 averaging period, but wait…
2011 Summer AERA Training
3
Long-term temperature record
2011 Summer AERA Training
4
Modifying the normals
2011 Summer AERA Training
5
Modifying the normals
2011 Summer AERA Training
6
Modifying the normals
2011 Summer AERA Training
7
Modifying the normals
2011 Summer AERA Training
8
Modifying the normals
2011 Summer AERA Training
9
Modifying the normals
2011 Summer AERA Training
10
Modifying the normals
2011 Summer AERA Training
11
New Normals

National Climatic Data Center is computing
new normals of station
–
–
–
–


temperature (maximum, minimum and average),
precipitation,
snowfall and snow cover
heating and cooling degree day information.
Normals for all these variables will be for daily,
monthly, seasonal and annual time scales.
For 250 Local Climatological Data stations:
– Hourly averages will include humidity & wind
information.
2011 Summer AERA Training
12
Climate Stations





2011 Summer AERA Training
Temperature
~7500 stations
Precipitation
~8700 stations
Snow
~ 6400 stations
Snow depth
~5300 stations
Hourly
~260 stations
13
New Normals Schedule



1 July 2011 -New 1981-2010 normals of temperature,
precipitation & degree days made available to
public.
1 Aug 2011 -NWS begins use on workstations.
31 Dec 2011 -All other normals (the “ag normals”).
2011 Summer AERA Training
14
Preliminary Results



Changes between 1971/2000 & 1981/2010 due to:
– Changes in climate
– Changes in stations, instruments & observing procedures
New normal temperatures
– Slightly higher than previous normals for many areas of nation.
– Due to inclusion of warm 2000-2009 interval.
Increases in temperature are not uniform across nation and from
season to season.
2011 Summer AERA Training
15
How do new normals differ?
Source: A. Arguez, NCDC (Jun 2011)
Summer – Jul Max Temps
2011 Summer AERA Training
16
How do new normals differ?
Source: A. Arguez, NCDC (Jun 2011)
Winter – Jan Min Temps
2011 Summer AERA Training
17
Changes for Wisconsin
2011 Summer AERA Training
18
Changes for Wisconsin
2011 Summer AERA Training
19
For more information
 NCDC
http://www.ncdc.noaa.gov/oa/climate/
normals/newnormals.html
 Or email
[email protected] from
http://www.aos.wisc.edu/~sco
2011 Summer AERA Training
20
The Wisconsin State Climatology Office Web Page
http://www.aos.wisc.edu/~sco
2011 Summer AERA Training
21
Views of State Climatology Office
2011 Summer AERA Training
22
19th Century Weather Data
2011 Summer AERA Training
23