Weather Forecasts: The Unsung Hero of The Farm
It should come as no surprise that we check the weather forecast multiple times per day here on the farm. This weeks blog post is going to be a deep dive into how we use forecasts on the farm for our decision making and how that plays a critical role in our ability to grow healthy, sustainable produce for your family.
Before we get into the decision making side of weather forecasts we need to understand a few basics about how meteorologists create forecasts in the first place. I am by no means a meteorologist nor an expert on the intricacies of forecast models but I’ve spent enough time reading weather blogs (thanks Updraft from MPR News) to understand more than the average person.
All forecasts you see come from complex supercomputer models that are constantly fed observational data from weather stations across the globe. These models spit out weather forecasts based on the observational data fed to them. That’s why weather forecasts constantly change day to day and why the further into the future you try to forecast the less accurate that forecast is.
3 different snapshots of a weather forecast for this weekend. Notice how all models are in agreement that the area just southeast of Mankato - where our farm is located - is not favored for the heaviest snowfall.
You can see a list of the models, courtesy of Wikipedia, here. The two that are referenced the most in the Updraft blog are the GFS model and the European Model. What’s useful about this is that the models aren’t always in agreement on what the forecast is. When the models ARE in agreement it signifies that whatever weather they’re predicting is significantly more likely to occur.
A little sidebar about GFS; this forecasting model is owned and operated by the United States Government under the National Oceanic and Atmospheric Administration’s National Weather Service which was recently cut significantly by Elon Musk and his goons at DOGE. Obviously, we care deeply about having the best, most accurate weather forecasts available so we can make good decisions on our farm and we are wholly against the cuts to the National Weather Service among the other agencies on the chopping block.
Anyway. Now that you have a basic idea of the behind the scenes on how weather forecasts work we will dive into which weather forecasts we use the most and how we use them to make decisions on the farm.
My favorite weather forecast tools are the Updraft from MPR News, weather.gov, and Weather Underground on my phone. Of the three I find Weather Underground to be the least accurate but it’s useful for seeing forecast temperatures which are usually pretty accurate and its radar is good for day-of storm tracking. Weather.gov is great for a couple reasons. First, it has a graph view where you can see the probability of various weather events like wind speed, wind direction, temperature, precipitation potential and more on an hour by hour view. I particularly like this when I try to determine if we should set up our canopy tents at the farmers market or not. Finally, Updraft from MPR News is my favorite because they not only give you a forecast but they talk about the “behind-the-scenes” science that informs the forecast as well as talking about the differences in the GFS and European forecast models.
Knowing wind speed, timing and directions can help us avoid costly mistakes like this ripped tunnel plastic. $800 in plastic and half a day of labor for 4 people required to repair.
To put a bow on this weather forecast blog post let’s talk about the different types of decisions we make based on weather forecasts.
High Tunnel Management: Our tunnels require accurate weather forecasts for proper management. We need to know wind speed and direction to know where we should vent tunnels to minimize risk of damage. We need to know temperature and cloud cover to know if we should open our tunnels, close tunnels or apply shade cloth. We need to know when a storm is coming so we can shut our tunnels completely if a severe storm is forecast.
Planting Dates/Times: Our planting schedule is complex and long and in order to have as consistent supply of our produce as possible we need to plant on schedule. Knowing that it’s going to rain for a week allows us to plant our crops before the rain comes so that we can stick to our schedule as much as possible. We also need to know if we should set up our outdoor irrigation or not and weather forecasts allow us to do that. Knowing there’s a 80% chance for rain means we don’t need to spend the labor setting up irrigation.
Staff Safety: Knowing when and where a severe storm will hit allows us to keep ourselves and our staff safe during severe weather. Further, knowing temperature and heat advisory allow us to plan ahead and start work early to try and beat the heat.
Canopies at the Market: Knowing wind speed, direction and timing allow us to set up our canopy tents at the farmers market more safely. Often if a forecast calls for high winds it’s likely that the winds won’t pick up until the afternoon so knowing precise timing of when winds are forecast to increase to unsafe levels for our canopy tents allow us to make the best, safest decision regarding our canopies.
Rainbow over our farmers market stand after a short rainfall just before we opened for the day.