Wind Direction Tendencies

[X-farmerdan]

We talk a lot of scent control and wind. We are well versed in how to play the wind - Upwind and downwind consequences and rewards. We've all hunted the properties we hunt to know the tendencies of wind direction, right? I don't know for sure.

I had an acquaintance ask me how to hunt a 12 acre parcel he had just been given permission to hunt. I had a couple suggestions after looking at the aerial images and topos of the property, but I had only assumptions about how to approach a stand location not knowing general wind direction. I guess I could assume west? Or south?

I'm a numbers believer - a data nerd. Given all the information we now have I started looking for something that would reveal speed and direction tendencies for a given area.

It's out there! And, after looking at a few wind roses, a graph that plots speed and direction for a given date(s) and time periods (sometime hour by hour), I'm a little surprised.

Most of you will look at this and throw it away. Some of you will immediately pronounce it gold! And the rest will stick it somewhere. Hopefully in the back of your mind for later reference.

Like with most all research of this kind, the test is an area not specific to you. For example, lots of whitetail research is conducted on deer in pens. Then we make inferences, correctly or not, to the wild population.

How this applies to you is based on your judgement and experience. Of course there's a lot to more to it. Other thing is this stuff's hard to find. For you guys in the midwest there's this thing called the mesonet.

http://mesonet.agron.iastate.edu/sites/dyn_windrose.phtml?station=MSN&network=WI_ASOS

So, I'll keep looking. I think it's cool!

 

[X-farmerdan]

Sorry. It got away from me. See how direction changes in the afternoon

 

[j-bird]

So - if I read these properly in the month of October the majority of the winds in the morning hunting hours where from the west, while the majority of the evening hunting hours the wind was from the south. I can see where this would help you generalize or maybe prioritize a particular stand set-up but you are still going to have to remain flexible. Say you have a square property - this info tells you that you need a real good morning stand to hunt a wind form the west AND you need a different but again very good stand to hunt evenings with a wind from the south. This will help you prioritize investments in stands and time and the like for a property. However you are still going to need stands for the other wind directions.....but those may not be worth putting near the effort into. I can also see this being put to use in developing "sneak trails" for bucks around food plots and bedding areas.....this info tells us to make them North and east of the plot or bedding areas. I also see how this becomes maybe less important in more hilly to mountainous areas as the wind doesn't blow in a straight line any way in those areas. But it can tell you which ways again to focus on in your wind mapping efforts to try to gain an edge.

With information, nothing is black and white and you always have to adapt it to the rest of your information. local conditions are always going to have to be considered.

Interesting info thought Dan.

 

[j-bird]

For grins I used the link and looked up my general area. per the data below you can gain some general knowledge and make some generalizations....


This says I need to not worry about hunting a wind from the East n most cases. It also says I should REALLY FOCUS on hunting when the winds are form the South.....because it's going to happen.....A LOT! Obviously you can dig a lot deeper if you so choose.....I have not....yet.

 

[X-farmerdan]

J, I'm not sure, yet, how to get to the data. I wanted to go back and look for your particular situation and fell short. I need to go hunt now! I think what you got was the general wind direction tendencies for every day / month / year for the period 10/1/1987 to whatever current end date you chose. So, your graphs include summer and winter and spring. I know it was just a test, but I would think direction might be different in October, November, and December. Maybe different each month.

 

[Turkey Creek]

A few years back I found a weather history site. You could plug in your location and it would give you the number of days per month that the wind was from any given direction in the past.

 

[Tap]

I've been quite serious about watching the wind religiously for at leat a dozen years now.
It's been a big challenge trying to figure it out, especially in hilly terrain.
It always seemed like the weather radio and Web sites were wrong, to the tune of 180 degrees wrong.
But that website Windy.com has convinced me that my hunches the last few years are correct.
I firmly believe that the complex wind patterns in hills and valleys are do to eddies. Both macro and micro eddies. Winds aloft are often what drives surface direction. Just because a upper level wind is from the North, it may or may not be doing that at ground level. The angle and speed that winds aloft pass over terrain and structure are what dictates where low pressure causes winds to eddy and swirl and the high pressure areas produce more stable winds.
Those winds aloft change directions with weather systems and fronts, but it's how those upper level wind directions are in relation to terrain that actually effect what's happening on the ground.
What used to seem like confusing, haphazard winds are finally starting to make sense.
It's still pretty complicated when wind speed and thermal influence is involved, but Im beginning to see that paying attention to the direction of winds aloft is the key. Now, figuring out how they effect surface direction because of terrain could take quite a while to figure out...maybe years for a given property.

 

[j-bird]

J, I'm not sure, yet, how to get to the data. I wanted to go back and look for your particular situation and fell short. I need to go hunt now! I think what you got was the general wind direction tendencies for every day / month / year for the period 10/1/1987 to whatever current end date you chose. So, your graphs include summer and winter and spring. I know it was just a test, but I would think direction might be different in October, November, and December. Maybe different each month.

Those I posted are for months of October, November and December, but from 1987 to 2015 as I understand it. So it's almost 30 years worth of winds for all hours of the day for the month of October, November and December as I understood it.

 

[Mennoniteman]

Someone had posted about the site windy.com, it's becoming my number one wind app.

https://www.windy.com/?40.175,-76.308,5,m:eMpad2P

 

[Tap]

So I had some time to look at the site farmerdan shared. 1st, I can't seem to find any windrow data for my area with is pretty typical...there isn't much support for ag resources around here.

But I'm wondering for those areas that do show the charts (like J-bird's), what exactly is the criteria or method of reading the wind direction?
Are these true surface readings, or are they based on readings of winds aloft?
If it's of true surface readings then the charts are only good for that exact location because, for hunting applications, we need to understand what the wind is doing (or will be doing) relatively near our stands and those very localized types of wind conditions are highly dictated by terrain.

My point in my earlier post was that if we pay attention to what angles the winds aloft are to the terrain, we can make fairly accurate assumptions on how those winds "morph" as they meet the terrain in our woods.
If you use wundermap for instance, you can see hundreds (many hundreds) of personal weather stations (PWS) scattered all over the country. There are dozens in my area alone and at each location, they each show their specific location's wind direction, speed and temp. They are in all sorts of locations...on hills, in deep valleys, and all compass exposures.
At any given time, those PWS will all show wind directions, and sometimes each are coming from a different compass direction all at the same time. But the winds aloft are still coming from only one direction. Why the discrepancy between the winds aloft and the PWS each showing a different surface direction?
Simple...terrain effects wind just like rocks and structure effect water flow in streams. We need to study upper level wind and how it's direction angles across our specific terrain.

I sat in a stand located part way into an E-W valley all day on Tuesday. (I was on the north exposure side of that valley) The winds aloft were from the North. It seems logical that at my stand the wind should have been blowing South, right? It didn't. All day long the wind at my stand blew to the North with an up draft as shown by milkweed. I know what was happening. As the wind blew over that E-W ridge to my North, it was creating a low pressure area in my valley. The air was being sucked back to the N and up. I'm sure that when "my" wind gained altitude, it blended in with the wind aloft and blew to the south...just like the weather system dictated.
Had that wind aloft been blowing at a 90 degree angle the wind conditions and consistency would have been completely different. And the exact contours of the terrain and windspeed would also play a big part in how those winds may or may not eddy.

The main driving force on stable or erratic winds is high and low pressure. The high pressure on the windward side of structure or hills creates stable or uplifting air current.
The low pressure area on the leeward wind side of structure or hills creates swirling and eddies. Wind patterns are so freekin complicated in hilly terrain, but understanding the principles and physics of pressure helps make what the wind does on any given day more explainable and somewhat easier to predict.

 

[X-farmerdan]

There's absolutely no doubt having years of experience with a specific plot of land and being observant stands well above any generalized data provided by a single observation station some distance away.

After having looked at a couple of these wind direction compilations it causes me to start thinking in different directions. I don't have the opportunity to be at a site long enough to really grasp what's going on with wind generally. I go. I consider what's happening on that day and make a plan. Different day different plan. maybe that's good enough.

There's a wonderful 25 acre tract our hunt club leases that seemed virtually unhuntable given the limited access to the property and my assumptions about typical wind direction. Having looked at the graphs I'm going to have to re-think my premise.

Yes, I have to make assumptions. I'm going to assume the observations at a station 8 miles away do apply to this tract of land. Time will tell if I'm right or wrong. I'm going to think about opportunities and what can go right and what can go wrong. Previously the window was closed. Now its open and reconsideration is on the table.

The graphic for October, 2017 is below. It's a start. I'm going to over analyze the data by looking at hourly trends over more than one year. I know not everybody wants to do this. I like it and its just another part of my joyful hunting experience.

I would have never believed the tendencies shown. Winds from the south (perfect for my situation) 20% of the time. Virtually no wind 30%. What does that do to the hunt? No wind?. Maybe 15% from the northwest back around to the northeast. That doesn't work. I guess this just exposes my ignorance, but I would have guessed the tendencies to be nearly opposite.

My new plan might be a total farce, but I see some hope where, before, there was none. I just love getting to the "ah ha" moment.

 

[Doe Shooter]

Someone had posted about the site windy.com, it's becoming my number one wind app.

https://www.windy.com/?40.175,-76.308,5,m:eMpad2P

Me too. Thanks