April Showers Helped Snowpack, Streamflow Forecasts
April showers are supposed to bring May flowers, but the cold temperatures have even slowed down blooming of the usually abundant wildflowers in western Montana. And no matter how much rain and snow fell in April, Eastern Montana is stuck in drought conditions for another year.
Winter was not what the Natural Resources Conservation Service (NRCS) was expecting. Three months of dry, cold conditions in all but northwest Montana left snow surveyors wondering about streamflow for the summer. The month of April brought "above normal" snowfall to much of the state and snowpack increased in almost all river drainages. Additionally, cold conditions has held back significant upper elevation melting of the snow, too. So, the NRCS streamflow forecasts have improved.
Improvement probably won't be noticed in eastern Montana, where the year-after-year drought is still hanging on. The U.S. Drought Monitor lists most of the river drainages in either "severe" or "extreme" drought. And, even much of western Montana is in the "Abnormally Dry" category.
Looking at the monthly NRCS snow survey for the Western Montana mountains at the beginning of May - The Bitterroot River mountains have an average 107 percent snowpack, the Upper Clark Fork is at 98 percent, the Lower Clark Fork is at 103 percent. The Flathead snowpack is normal at 100 percent.
When you go over the Continental Divide, only the Sun-Marias snowpack is above 100 percent. Everything else is below average. For instance, the Gallatin snowpack is 89 percent and the Helena Valley is only 75 percent of average.
The cool weather put April river streamflows below average. If May and June continue cool with more rain, that will help stretch out the streamflow. But, with the continually wild swings in weather patterns, it's basically a gambler's coin-flip as to what will happen. Right now, the Bitterroot River streamflow is expected to run about 110 to 130 percent. But places in eastern Montana could be as low as 70 percent.