Weather Journal

Autumn's First Hint

I have always experienced one instance during early August when a weather change brings me the first reminder that Autumn is on its way. The sign is often subtle, not the frigid blast such as hit western Canada this past week with measurable snowfall. No, it manifests less as a sledge hammer blow and more a transient moment through a smell in the air, or the touch of a cool, dry breeze.

The autumnal hint always arrives following passage of a cold front when the warm, humid air of summer is replaced by cool and dry. In the post-frontal air something special, an embryonic precursor of the arctic air, reminds me of the approaching change of season. These vapours have a freshness that, were it a wine, would bring a smile to the taster's face.

Its impact is subtle yet so recognizable that when I encounter the situation each year, I know immediately. "Mmm, Fall is in the air....Summer is ending." The bittersweet realization pops into my head spontaneously. I know, no need to analyze.

What properties or combinations elicit the trigger, I do not know. Cool is definitely in the mix...and dry. Is it therefore a crossing of a cool-dry threshold combination for the first time? Does sky colour or angle of the sun have a role?

I once thought that some minute concentration of chemical in the air, a seasonal pheromone, might be involved. The compound perhaps arose from some biological process unique to this time of year and was carried to me on the breeze. I have had the same reactions here on Vancouver Island, however, that arose in me during my years in the Great Lakes basin. If it is a smell on the wind, it is fairly common across the continent.

I have no ready answer to my quandary even today. The feeling comes each year and comes but once. Perhaps, it is a uniqueness to the entity that is Me, a mix of biology and experience. I often do wonder if it is a deep-seeded trigger tied to some dormant gene that once alerted an evolutionary ancestor to migrate or begin preparing for hibernation or winter scarcity.

I guess I will never know why. I do, however, know that one day in the next few weeks, I will step outdoors, breathe in the air and from within, a little voice will say: "Summer's drawing to an end. Here is the seed of Autumn."

Learn More From These Relevant Books
Chosen by The Weather Doctor

• Williams, Jack: The Weather Book, 1997, Vintage Books, ISBN 0-679-77665-6.
• Burt, Christopher C.: Extreme Weather: A Guide and Record Book, 2004 (pb), W. W. Norton & Company, ISBN 039333015X.

Written by
Keith C. Heidorn, PhD, THE WEATHER DOCTOR,
August 14, 2002

The Weather Doctor's Journal Autumn's First Hint
©2002, Keith C. Heidorn, PhD. All Rights Reserved.
Correspondence may be sent via email to: see@islandnet.com.

For More Weather Doctor articles, go to our Site Map.

I have recently added many of my lifetime collection of photographs and art works to an on-line shop where you can purchase notecards, posters, and greeting cards, etc. of my best images.

To Purchase Notecard, Greeting Cards and Posters featuring my images, visit The Weather Doctor's Nature Gallery

Now Available! Order Today!
NEW! Now Available in the US! And Now...The Weather by Keith C. Heidorn To Order in Canada: And Now...The Weather by Keith C. Heidorn	The BC Weather Book: From the Sunshine Coast to Storm Mountain by Keith C. Heidorn