By Indecision on Wednesday, November 28, 2007 - 12:24 pm: Edit Post
I was reading your forecast text today and came across the "Bayfield Bomber". I had to chuckle a little at first as I'd never heard of that growing up there but I suppose that's because it doesnt actually affect our area....so to everyone reaping the benefit's - you're welcome.lol
Could you explain the "bomber" a little better?
I thought for LES in both peninsulas you need a NW wind but if I read correctly, that would seem to be a SW wind.
By Average Joe on Wednesday, November 28, 2007 - 01:21 pm: Edit Post
Indecision, While you are waiting for John's response, you can read about the "Bayfield Bomber" near the end of his January 11, 2005 journal entry. It's a nickname.
By John Dee on Wednesday, November 28, 2007 - 08:11 pm: Edit Post
That is actually a term I coined back in 1998 which is the first ever saw it occur. I was actually still living in the Chicago area and would monitor the weather very closely via satellite, radar and surface observations from the airport.
I named it not because it impacts the Bayfield Peninsula, but because it forms there.
Lake effect snow will occur best when the air is allowed to travel over the most water. That way it is able to be heated and moistened the most. A westerly wind allows the air to be over the water for the longest distance before hitting the Keweenaw- about 3 times furthern than with a NW wind.
With a west, southwest wind, the air will travel in a line from the Bayfield Peninsula and travel over the Keweenaw. Because the air is rising over the lake, a land breeze can form near the shorelines of Gogebic and Ontonagon Counties. This causes the low level winds to converge. That convergence enhances the lift, which in turn enhances the Lake Effect Snowfall formation. It is also possible for the Bayfield Peninsula to start the converging winds.
So you end up with what is a 25-40 mile wide band of very heavy snow that stretches from near the northern tip of the Bayfield Peninsula across the Keweenaw. Snowfall rates usually run at least 1-3" per hour, although can reach 4-6"/hr. With snowfall rates like that, it does not take long for the snow to pile up and I have seen accumulations in the 1-3 foot range occur in less than 24 hours.
Since living up here I have been in 2 of the bombers and seen other areas of the Keweenaw impacted several times. If you read the journal entries after that January 11, 2005 entry, you can see some of the effects. I don't think we had a full fledged bomber develop, but the west wind did bring about 20" of snow in a few days. You can also check out the December 20th, 2005 journal entry for some pics of a brief and very narrow bomber that hit the northern 1/2 of the Traprock Valley and our property for about 5 hours. About 18" fell in that event in that 5 hours. Some nice powder riding that next day!
By Indecision on Thursday, November 29, 2007 - 10:58 am: Edit Post
That makes sense. I wish the Bayfield peninsula received heavier LES but I suppose that's due to the limited distance to the MN shoreline-similar to what you explained in one of the above paragraphs. Isnt the term for that "fetch"?? Please correct me if I'm wrong.
Thank you for your response. The ask John topics are great - very informative.
By John Dee on Thursday, November 29, 2007 - 11:49 am: Edit Post
Yes, fetch is the term used for the distance the air travels over the water.