3.5 Long Range
Long-range forecasts provide important hydrologic information for many commercial industries, and you are the forefront of the production of these forecast.
What are Long-Range Forecasts?
Long-range forecasts are deterministic forecasts of stage or flow for longer than the typical five-day forecast period.
Example: MBRFC issues a 28-day forecast for the Missouri River.
Users
The navigation industry is the primary user of long-range forecasts. Other users include recreation and agriculture.
Differences from Daily Forecasts
You must set the relative view period of the time series to 30 days and ensure reservoir outflows are reasonable for the entire forecast period.
The time window of the displayed data.
Many users prefer the worst-case scenario for river flows, so the model does not use additional days of QPF. The 28-day run does include projected snowmelt runoff.
CHPS Configuration Focal Points have the workflows configured to pull in data for the right amount of time. You do not need to worry about setting the dates. Instead, focus on making sure the reservoir outflows are correct.