First Freeze Information for 2012, Etc……..October 6th, 2012 at 1:07 pm by Chad Evans under Chad's WLFI Weather Blog
Some of you had your first freeze of the season this morning, but many of you have still not had your first freeze. Below is information regarding where we are with the occurrence of 32 this autumn & when it normally occurs. The Purdue Agronomy Farm & Purdue Airport both nudged down to 32 this morning, but the morning low was 32.6 at the station, making it a 33-degree morning. We were 0.2 of a degree from 32.
I took freeze dates from all the COOP stations at these locations & nearby since 1970 to figure this data. I went longer than a 30-year period to account for any recent later or earlier freeze dates in the past 30 years, so it is not skewed too much. I like figuring up longer freeze dates (for example over a 50- or 40-year period, as climate is measured in half centuries, even centuries, just not decades). Some decade-long warm stretches skew data a lot. If you take 1950-1980, your freeze dates are days earlier than 1980-2000, but if you average them all up, you get a nice, average freeze date.
On NOAA sites, it is confusing. Midwest Climate Center has different freeze dates than NWS offices & the dates at the Indiana State Climate Office are different, too. For example, Midwest Climate Center has first freeze date October 11-20 for Rensselaer, but NWS Chicago has it as September 30-October 7 & Indiana State Climate Office has the date at Rensselaer right on the line of October 1.
1981-2011 average first freeze dates vary for the Purdue Agronomy Farm between NWS Indianapolis, Midwest Climate Office & State Climate Office between October 9 (NWS), October 1-10 (Midwest Climate Center) & September 27-1 (State Climate Office).
So, to just prevent all the confusion, I just re-figured up all the dates, as there is no solid consensus between any state or federal weather/climate office. Just want to keep it consistent & not confusing.
Skies are mostly sunny in the viewing area, but stratocumulus pivoting southward will tend to turn skies partly to mostly cloudy from north to south. A few isolated sprinkles or a brief light shower may even be spit out from these this evening in places.