Henry’s Fork, March 16th, 2024
Limited access prevails along the lower river. BWOs are out and with an extra hour of daylight more time is available to enjoy trout responding to them. Expect the river to cloud a bit as the warm weather will enhance bank side and nearby melting.
| Fun Farm Bridge | ||||
- Water-year total precipitation stayed at 106% of average, while SWE dropped a percentage point to 95% of average.
- Dry and warm weather is expected for the next six days.
- At an outflow of 416 cfs, Island Park Reservoir dropped by 92 ac-ft yesterday and is 91% full, compared with 80% full on average.
- The upper Snake River reservoir system is 88% full, compared with 68% full on average.
- Total reservoir storage plus existing snowpack across the basin is high enough that water will be spilled out of the system at Milner Dam starting on March 25.
Details
New snow water equivalent (SWE) over the past four days ranged from 0.2 inch at Pine Creek Pass to 1.7 inch at White Elephant. Current SWE is 95 of average: 92% in upper Henry’s Fork, 97% in Fall River, and 99% in Teton River. Current SWE ranks 17th out of the 36 years (54th percentile), just ahead of 1998 and just behind 2002. After the upcoming six days of dry weather in the forecast, SWE will fall to around 91% of average and drop several places in the rankings.
Dry conditions with above-average temperatures are expected for the next six days, before precipitation returns late next week. Valley snowmelt is expected, and that will increase streamflow a little. However, below-freezing nights will keep mid- and high-elevation snowpack intact before more mountain snow and valley rain is expected late next week. Long-term outlooks are leaning toward above-average precipitation, with gradually cooling temperatures 1–2 weeks out.
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420