Changing the Climate Normals

AWXVTEC FEED | July 18, 2011 @ 8:29 am | 4 Replies

Today’s “normal” high in Birmingham is 91 degrees; in Huntsville, the “normal” is 89 degrees. The “normal” or sometimes called “average” high temperature for a given place is based on a thirty-year average. Every ten years, the average is recalculated using the most recent 30-year period. Huntsville’s National Weather Service will make that change on August 1st moving from the 1971-2000 period to the 1981-2010 period.

This is somewhat significant because, according the the NWS Huntsville (click here for the charts), the average daily highs and lows will be warmer than the previous data set. That is because we have replaced a cooler period in the 1970s with a warmer period from 2000 to 2010.

There is no intention to make a case for or against anthropogenic global warming here; if anything, it shows that the climate does change, but this simple set of data in no way gives an indication of the processes (be they natural or not) behind the changes. If we see that temperatures are consistently below the averages over the next ten years, then it would give credence to the idea that the warming in the 90s and 2000s was part of a cycle; if we are consistently “normal” or above through 2021, it would give support to the theory that the planet is warming. Even that still cannot prove it is either man-made or natural, though. In other words, good temperature measurements and honest scientific comparison will reveal the truth in due time.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
657 AM CDT MON JUL 18 2011

…CHANGE TO NEW 1981-2010 CLIMATE NORMALS EFFECTIVE AUGUST 1ST…

THE NATIONAL WEATHER SERVICE WILL INCORPORATE THE NEW 1981-2010
CLIMATE NORMALS INTO OUR CLIMATE TEXT PRODUCTS ON AUGUST 1ST. THE
PRODUCTS ISSUED LOCALLY BY THE NATIONAL WEATHER SERVICE OFFICE IN
HUNTSVILLE AND AFFECTED BY THIS CHANGE WILL BE:

DAILY CLIMATOLOGICAL REPORT (CLI)
MONTHLY CLIMATOLOGICAL REPORT (CLM)
ANNUAL CLIMATOLOGICAL REPORT (CLA)
PRELIMINARY LOCAL CLIMATOLOGICAL DATA REPORT (CF6)

ANY PRODUCT CONTAINING DATA THAT CROSSES THE AUGUST 1ST
IMPLEMENTATION DATE…SUCH AS THE DAILY CLIMATOLOGICAL REPORT OR THE
ANNUAL CLIMATOLOGICAL REPORT…WILL USE THE NEW 1981-2010 CLIMATE
NORMALS FOR REQUIRED CALCULATIONS FOR THE ENTIRE PERIOD. FOR
EXAMPLE…THE NORMAL PRECIPITATION SINCE JANUARY 1ST THAT APPEARS IN
THE DAILY CLIMATOLOGICAL REPORT WILL REFLECT THE TOTAL FROM THE NEW
1981-2010 NORMALS BEGINNING ON AUGUST 1ST.

PRODUCTS ISSUED PRIOR TO THE CHANGE DATE WILL NOT BE REISSUED USING
THE NEW CLIMATE NORMALS.

THE NEW MONTHLY CLIMATE NORMALS FOR HUNTSVILLE AND MUSCLE SHOALS ARE
NOW AVAILABLE FROM AN INFORMATIONAL WEB PAGE AT:
HTTP://WWW.SRH.NOAA.GOV/HUN/?N=CLIMATE_NORMALS_1981-2010_OVERVIEW
(ALL LOWER CASE)

THE NEW DAILY TEMPERATURE AND PRECIPITATION NORMALS FOR HUNTSVILLE
AND MUSCLE SHOALS WILL BE MADE AVAILABLE FROM THIS PAGE IN THE COMING
DAYS.

CLIMATE NORMALS ARE CALCULATED EVERY 10 YEARS AND ARE BASED ON AN
AVERAGE OF 30 YEARS OF CLIMATE DATA. THE CALCULATIONS ARE DONE BY THE
NATIONAL CLIMATE DATA CENTER. MORE INFORMATION ABOUT THE CLIMATE
NORMALS CAN BE FOUND AT:

HTTP://WWW.NCDC.NOAA.GOV/OA/CLIMATE/NORMALS/USNORMALS.HTML
(ALL LOWER CASE)