Predicting Tomorrow

We are entering the time of year where water, flows and forecasts are heavy on the mind. While the storage capacity of upstream dams is looking good and snow-water equivalent values are within average range- there remains much uncertainty when trying to predict what will happen tomorrow, let alone a month from now.

To highlight this complexity in forecasting, I worked with Montana Meteorologist Ryan Dennis late Thursday night/early Friday morning to run models on what Saturday's weather will look like for the Bighorn Basin. I mean, tomorrow can't be hard to predict, right?

At the weather station, Ryan worked to answer my question by running forecasts aimed for predicting conditions for Saturday, March 29th, at 6 AM. Ryan used three of the stations most trusted high-resolution forecasting models, with all models using the same input parameters and differentiating only in respect to algorithm.

Here's what we got.

MODEL 1

Results from model 1 show clear conditions for the entire Bighorn Basin for Saturday morning at 6 AM. Precipitation hitting the east side of Wyoming either already passed through or bypassed the area all together due to arriving from the south.

MODEL 2

Conditions with Model 2 are still looking clear for the Montana section of the Bighorn River on Saturday at 6 AM but does show the Wyoming portion of the basin as waking up to rainfall. Higher up in elevation we see the Bighorn Mountains receiving a broad band of snow, with a portion of that snowfall accumulating on the Bighorn basin side of the drainage.

MODEL 3

Anglers using this model would probably pack some raincoats and prepare for chances of rain if hitting the river at 6 AM on Saturday. Basin wide, we can anticipate a high probability of moisture, with snow isolated to the Bighorn Mountains in Wyoming, and not extending as broadly as in Model 2.

All models - prompted with the exact same inputs show different results, reminding us that forecasting remains a difficult and imperfect science - even when looking to predict conditions a day away. With that, I thank Meteorologist Ryan Dennis for working with us to showcase how hard it is to answer seemingly simple questions pertaining to the future. As they say in Montana, if you don't like the spring weather, just wait a few minutes and it will likely change!