1:50 p.m. Friday update: The geomagnetic storms that generated northern lights above Colorado Thursday night are on the wane, but there’s at least a chance that the colorful atmospheric phenomena will return in “bursts” Friday night.
Bryan Brasher, a project manager with the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center, said Friday afternoon that the agency has downgraded its geomagnetic storm watch from a G4, the second-strongest storm level, to a less severe G1.
“Brief bursts are possible, but expectations should be tempered,” Brasher wrote in an email.
“While solar wind speeds remain slightly elevated, the embedded magnetic field is much weaker and not in a favorable orientation for intensifying activity. So, while we may experience unsettled conditions, the chances for aurora sightings at low latitudes — like Colorado — tonight are low.”
The National Weather Service predicts mostly clear skies above Denver Friday night, with an overnight low of 50.
Previous reporting: The northern lights will color Colorado skies once again Thursday night, according to the National Oceanic and Atmospheric Administration.
Last week’s burst of geomagnetic storms was just a sampling of the ones expected to reach Earth Thursday, meaning the lights will be more vibrant and easier to see — especially if you know where to look.
The NOAA’s Space Weather Prediction Center a severe, G4 geomagnetic storm watch for Thursday — the second strongest storm level on the scale.
Space weather officials said a G4-level coronal mass ejection “erupted from the Sun” Tuesday evening and is expected to arrive at Earth on Thursday.
G4 storms are rare, according to space weather officials. When abnormally strong geomagnetic storms occur, bright northern lights will be visible at unusually low latitudes. The aurora borealis has been seen as low as Alabama and northern California during severe, G4 storms in the past.
The fastest coronal mass ejections can reach Earth from the Sun in 15 to 18 hours, and slower ejections can take several days to arrive, NOAA officials said.
When the ejections hit the earth, they create geomagnetic storms that threaten power grids and voltage control, disrupt satellite services and low-frequency radio navigation systems and cause issues for spacecraft operations, weather officials said. They also create the aurora borealis.
Maps released by the NOAA’s Space Weather Prediction Center show the northern lights’ projected reach Thursday night, with northern Colorado making the cut for at least weak visibility.
Coloradans who want a better chance at seeing tonight’s light show will want to drive to the Wyoming border and find a spot with minimal light pollution. The drive from Denver usually takes less than two hours.
While the lights will be more visible and vibrant in the northern part of the state, Coloradans to the south can use their phones to boost the view. A phone’s camera can pick up the light’s wavelengths better than the human eye.
Thursday night will be partly cloudy in Denver, according to National Weather Service forecasters. Up north, near the Colorado-Wyoming border, smoke and clouds are expected to move out in the evening as winds pick up, leaving mostly clear skies to see the northern lights.
Single-day, next-day and hour-by-hour forecasts for the northern lights are available online via the NOAA.
Post courtesy of DenverPost.com.