NOAA's Space Weather Prediction Center has issued a G2 (Moderate) geomagnetic storm watch for tonight, May 15–16, after a high-speed solar wind stream from a large coronal hole — a gap in the Sun's magnetic atmosphere — struck Earth's magnetosphere. The storm gives millions of Americans from New York and Wisconsin to Maine and Montana a narrow window to see the aurora borealis without travelling to Arctic latitudes, while simultaneously stressing satellites and long-distance power lines in ways that affect services most people rely on every day.
Peak Activity Tonight: 11 PM to 2 AM EDT, With a New Moon Overhead
The storm is driven by a corotating interaction region (CIR) — a compressed wall of plasma that forms where fast solar wind overtakes slower wind shed earlier in the Sun's rotation cycle. Unlike a coronal mass ejection, which can arrive with little warning, CIRs build predictably, giving NOAA's forecasters several days' lead time. The agency flagged the incoming stream as early as May 13, allowing satellite operators and grid managers to prepare.
Storm intensity is forecast to peak between 03:00 and 06:00 UTC on May 16 — roughly 11 PM to 2 AM EDT tonight. G1 (Minor) conditions are then expected to linger through May 16–17 as the solar wind stream gradually subsides. A new moon this weekend means unusually dark skies, removing one of the main obstacles to seeing the aurora at mid-latitudes.
Aurora visibility is forecast as far south as New York, Wisconsin, Minnesota, Michigan, and Maine. NOAA's Aurora Dashboard and the Planetary K-index page, which updates every three minutes, are the most reliable real-time guides. A Kp reading of 6 or higher signals G2 conditions and confirms aurora is active.
To maximise your chances: drive at least 30–40 minutes from city lights, face north, and use a smartphone camera on a three-to-five-second exposure — modern sensors detect faint green and red auroral wavelengths the naked eye misses. Cloud cover across the Midwest and Great Lakes may obscure the display tonight; the clearest skies are forecast over parts of the northern Great Plains and New England.
What a G2 Storm Does to Satellites and the Power Grid
A G2 storm sits at the midpoint of NOAA's five-tier scale, and while it is not catastrophic, its consequences for infrastructure are real and immediate. High-frequency (HF) radio communications at high latitudes face disruption — a direct concern for transpolar aviation routes linking North America to Asia. Airlines that rely on HF radio over Arctic airspace may need to divert to lower-latitude flight paths to maintain communications.
For satellite operators, a G2 storm raises two specific hazards. Magnetometer interference can cause temporary orientation errors in spacecraft attitude-control systems. And geomagnetic heating expands the upper atmosphere slightly, increasing drag on objects in low Earth orbit — forcing operators of constellations such as SpaceX's Starlink and OneWeb to fire thrusters more frequently to maintain orbital altitude, burning finite propellant and reducing satellite service lifespans.
The drag risk is not theoretical. In February 2022, a G1-to-G2 storm struck the day after SpaceX launched 49 new Starlink satellites into a low staging orbit. Up to 40 of those satellites were lost when increased atmospheric drag — which SpaceX said ran up to 50 percent above normal levels — prevented them from raising to their operational altitude. Tonight's storm is considerably milder, and operational Starlink satellites at higher altitudes are far less vulnerable than that freshly launched batch was. But the episode illustrates how even moderate space weather translates into hundreds of millions of dollars in lost hardware.
On the ground, geomagnetically induced currents (GICs) — slow, quasi-DC currents that geomagnetic activity overlays onto long power-transmission lines — can drive transformer saturation at higher latitudes during G2 conditions. Transformer saturation causes core overheating, harmonic distortion, and accelerated insulation degradation. Widespread outages from a single G2 are uncommon, but repeated moderate storms cumulatively stress transformers in ways that shorten operational lifespans. NERC standard TPL-007-1 now requires U.S. transmission operators to evaluate their GIC vulnerability, and utilities in northern states have installed GIC-blocking devices as a precaution.
A NASA Instrument Launches Into the Storm It Was Built to Study
By coincidence, tonight's storm overlaps with the third launch attempt for SpaceX's CRS-34 resupply mission to the International Space Station, scheduled for 6:05 PM EDT from Cape Canaveral Space Force Station. Two earlier attempts on May 12 and May 13 were each scrubbed due to poor weather at the launch site.
Among CRS-34's payloads is STORIE (Storm Time O+ Ring Current Imaging Evolution), a joint NASA and U.S. Space Force instrument designed to image the ring current — the doughnut-shaped belt of energetic particles encircling Earth that swells during geomagnetic storms. When the ring current intensifies, it drives the surface magnetic disturbances that produce GICs in power lines and navigation errors in compasses and GPS receivers.
Once robotically mounted on the exterior of the ISS's Columbus module a few days after docking, STORIE will scan outward and build a full image of the ring current roughly every 90 minutes as the station orbits. Its six-month mission targets a fundamental question: are the energetic particles feeding the ring current sourced mainly from the solar wind or from Earth's own atmosphere? Oxygen ions (O+) are the diagnostic key — oxygen in the ring current originates in the atmosphere, not the Sun. Clearer answers will directly improve the precision of space weather forecasts, giving grid operators and satellite controllers better information when the next storm approaches.
Solar Cycle 25 Exceeded Its Forecast — and the Active Period Continues
Nights like tonight are likely to become more frequent, not less. Solar Cycle 25 — the roughly 11-year rhythm of solar activity currently underway — has consistently outpaced its original forecast. In 2019, an international panel convened by NOAA, NASA, and the International Space Environment Services predicted the cycle would peak at a smoothed sunspot number of 115 in July 2025. The actual smoothed peak, recorded in October 2024, reached 161 — 40 percent above the original projection.
Solar activity has remained elevated well into the cycle's descending phase. Early 2026 saw sustained X-class flare activity and the frequency of CIR events is expected to remain elevated through at least mid-2027. That extended period of heightened activity is why space weather researchers treat the next 18 months as a window of elevated systemic risk for satellite infrastructure and high-latitude power grids — not a one-off.
For aurora chasers, the same conditions mean tonight will not be the last opportunity this year. Signing up for free alerts from NOAA's Space Weather Prediction Center puts real-time storm warnings directly in your inbox before the next G2 — or stronger — event arrives.
ⓒ 2026 TECHTIMES.com All rights reserved. Do not reproduce without permission.
