Northern Tier: West to East or East to West?

[jamawani]

My resource is the Iowa Environmental Mesonet - as indicated on each image.
(Complete wind rose sets for multiple locations with user-friendly interface.)

I as state earlier -
"winds are variable in many parts of the country,
in the High Plains of Montana and Wyoming they do have a strong, prevailing westerly vector."
The Northern Tier has zillions of miles in central and eastern Montana. (As does the L&C)
In Montana, riding eastbound will encounter fewer headwinds - - on average.

** If I remember correctly, BikeCentennial recommended eastbound riding
when they first demarcated the Northern Tier. Could check old paper guides.

I did graduate work in Lawrence, Kansas and rode in the Flint Hills often.
I am well aware that as you get into the eastern Plains, winds vector southerly.
In Bismarck, winds alternate NW & SE - equally bad in either riding direction.
In Dickinson, winds alternate more closely to west and south,
Thus, in western ND winds advantage eastbound riders more often - - on average.

YMMV.

[fuzzyrider]

Monica, it sounds like most people are suggesting that you go west to east while some are saying that it doesn't really matter.  I would strongly agree with the former.  I did a straight version of the NT (straight through the great lakes instead of around them) west to east.  We meet many riders going east to west and most of them complained about the head winds.  We couldn't really appreciate their complaints since we were averaging close to 80 miles a day with very little head winds.  Until we hit ND.  We had one day of strong head winds and struggled ALL day just to ride 40 miles.  it was worse than going up hill.  I can now appreciate those other cyclists complaints and wouldn't want to do it again.  Since you love cycling but not heads winds I would suggest you "Go with the flow" west to east but know that there will be days with head winds so enjoy all the days that you don't have them.  Ride on!
        __o
      _`\ <,_
     (_)/   (_)

[John Nettles]

I too hate headwinds much more than climbs.  For me though I look at the intensity of the headwind when deciding.  I would favor going W>E since the strongest winds are in eastern MT and ND.  Yes you may get headwinds in other places but they are not the demoralizing 30+mph all day winds that where you out.

As a side note, as Jama indicated, in the northern plain states, the wind alternates it seem every other day between N & S at least in August.  On a 25-day 1700 mile trip from Mexico to Winnipeg, while in Nebraska to Winnipeg, I would do a 100+ mile day by 2:00pm (including lunch) and the next day was only 35 miles ending at 5pm.  All due to the strong winds.  Granted it was not literal but I did have 7 centuries on that 25-day tour and I normally only average only about 50-55 miles per RIDING day so it is not like I am some uber strong rider.

I would suggest you look at a few journals over on CrazyGuyonaBike.com and see what they say about the winds in Montana and N. Dakota.

Another non-wind thought is if you are an very early riser/depart to ride, E>W might be better so you do not have the sun in your eyes all morning. 

[jamawani]

According to the Wyoming Department of Transportation, nine vehicles blew over on Interstate 25 south of Cheyenne, while two were toppled on Interstate 80.

Vehicles began to tip over around 1 p.m. Tuesday. More than once, the falling vehicles caused crashes, WYDOT stated in a news release.

Aimee Inama, a WYDOT spokeswoman, said the agency was still working on compiling accident reports and she was thus unsure if anyone had been injured in relation to the blow overs.

Wind in southeast Wyoming topped 60 mph in several places and climbed over 80 mph at two Union Pacific locations several miles from Interstate 80, according to WYDOT.

http://trib.com/news/state-and-regional/nearly-a-dozen-vehicles-blew-over-tuesday-on-wyoming-highways/article_dc197112-905e-5e32-bf96-3a2a267503b2.html?utm_content=buffere0d6e&utm_medium=social&utm_source=facebook.com&utm_campaign=LEEDCC

They were WNW winds - NOAA.

[RussSeaton]

Another non-wind thought is if you are an very early riser/depart to ride, E>W might be better so you do not have the sun in your eyes all morning.

Tying this back to wind direction.  In the middle of the Midwest, the winds start increasing in strength late morning and in the afternoon.  Afternoon and early evening is when winds are generally strongest.  So an early start will mean riding with meager or non existent winds for the first few hours.  No matter whether they are head or tail winds.  On my Saturday 7 AM morning rides with friends, the winds are minor when we start.  But can be much stronger later in the morning when returning.