Mqt Season Snowfall Maps

[Bullitt69]

Hi John,

First of all, wanted to again thank you for all your hard work, you have a great site here with invaluable info for us snow geeks.

I have a question about the accuracy of the Season Snowfall Maps, in particular the ones that span over a ten year time-frame starting in 2002

http://www.weather.gov/mqt/seasonsnowfallmaps

I understand how typically lake snows tend to fall inland a mile or so due to the slowing of the winds (the land surface creating friction), and how an increase in elevation creates orographic effects, and typically lake effect peaks between about 15-20 miles or so from the shoreline, BUT

There tends to be a pattern in each of the maps from 2002 thru present that would lead you to believe that in areas (especially) north of the Portage Lift Bridge - there's a drastic difference of snow depth from the eastern side of the peninsula and western, e.g. places like Big Traverse, Gay and/or Betsy will get 100 inches a season, but Delaware and/or Phoenix (just 8 miles away) are getting 300 or more! I mean, the distance from shore to shore is only 15 miles in most cases or less.

(case in point, in the 2014-15 map it would suggest 100 inches at the Bete Gris Preserve and 272 in Delaware)

Is this a fault in these maps, or is there that much of a difference in snowfall from shore to shore?

I would greatly appreciate any thoughts on this. (I know it's geeky and irrelevant, but believe me, I ponder these things maybe too often)

Thanks,
Bullitt

 

[snoluver1]

I'm sure John will have a much more indepth answer, but I think you answered your own question. "and how an increase in elevation creates orographic effects"

There is a ridgeline that runs right up the middle of the peninsula. Delaware resides in some of the highest territory on the peninsula.

 

[jd]

Yep, that is the answer ^^^

Because the terrain drops off as you head past the spine (highway 41 almost follows it up the whole Keweenaw), the terrain drops off, so that boost you got by lift goes the opposite direction.

-John

 

[Bullitt69]

Thanks guys, I meant "Fault" in terms of Faulty, or an inaccuracy - not the ridges of Northern Keweenaw County. LOL!

So, the amount of snow really does drop off at Gratiot Lake then? There's a steep change in elevation right there - about 400-500 feet in fact.

At that point, the lake effect is about pooped out - that sound about right?

I imagine you would notice a similar difference between totals in Lake Linden and Calumet.

Cheers,