SALT LAKE CITY (ABC4) – iPhone owners and astute observers of weather apps may have seen a new warning appear reading “hydrologic outlook.” But what does that mean?
According to the National Oceanic and Atmospheric Administration, a hydrologic outlook is put into effect to provide information on conditions that could cause flooding within the next seven days.
On April 27 just before 1:30 p.m., a hydrologic outlook was issued in Utah and it was set to expire at 1:30 p.m. on April 28.
“Streams, creeks and rivers will experience significant rises moving forward into early next week, especially low and mid-elevation watersheds across the forecast area,” the hydrologic outlook said. “Waterways will be running high, fast, cold and extremely dangerous increasing the risk of hypothermia and growing with even brief periods of time in the water.”
The outlook warned of water rises due to increased snowmelt and that the public should stay away from waterways because of the dangers.
So how does an outlook differ from a weather watch, warning, or advisory? The National Weather Service said it has to do with the level of confidence.
“Flood and Flash Flood Warnings and Advisories convey a high degree of confidence, Flood Watches a medium degree of confidence and Hydrologic Outlooks a lower level of confidence,” said the National Weather Service in a 2014 directive. “The level of confidence typically decreases the further in time a forecast is projected.”
A hydrologic outlook is typically issued for a 30-50% chance of flooding within the next week. As the days with the greatest flooding potential nears, the outlook could be upgraded to a Flood Watch or even a Flood Advisory. It all depends on how likely and how severely it will happen.
The purpose of a hydrologic outlook is to make the public aware of flooding potential on the horizon. The late April hydrologic outlook came with an urgency warning that said “Take action in the near future,” calling on Salt Lake area residents to start getting ready for flooding potential.
Flooding concerns continue to rise across Utah as warmer springtime weather approaches. Localized flooding has already happened in areas such as Kaysville and Salt Lake. The Sugar House Park pond, which serves as a temporary detention basin for Parley’s Creek, is overflowing onto the roadway around the park – a sign that is working as intended, according to Salt Lake City officials.
Weather forecasts for the Salt Lake area show temperatures rising to above 80 degrees, which is about 20 degrees higher than seasonal averages. The rise in temperatures threatens Utah’s historic snowpack, which sits just below the 1983 record at 25.4″ of snow water equivalent as of April 28.