Solar Watch — May 16, 2026 | 18:00 UTC

☀ HELIOS SOLAR WATCH · 2026-05-16 16:00 UTC
Geomagnetic Activity Expected to Increase to G2 Levels Briefly
SOLAR: MODERATE
GEO: QUIET

Active Regions
2
X-Ray
A/B (quiet)

Geomagnetic conditions are currently quiet but are forecast to reach G2 (moderate) levels later today. This shift is likely due to the arrival of lingering solar wind stream effects.

HMI Continuum Intensity

HMI Continuum · Visible Light

SUVI 304 — Extreme UV

SUVI 304Å · Extreme Ultraviolet

R0
Radio Blackouts
24h max: R0

S0
Solar Radiation
24h max: S0

G0
Geomagnetic Storm
24h max: G2

Planetary Kp-Index
2.3
0–9 scale · ≥5 = geomagnetic storm

F10.7 Solar Flux
118.0
sfu · >150 = high activity

The planetary K-index is currently at 2.3, indicating quiet geomagnetic conditions following a period of higher activity. Solar activity remains moderate with an F10.7 flux of 118.0 sfu and limited C-class flare production from active regions AR4436 and AR4438. X-ray flux remains in the background A/B range, reflecting a generally stable solar environment.

Key Metric

The forecasted Kp of 5.67 is the most critical metric, as it indicates a transient G2 storm that may impact satellite drag and high-latitude radio propagation.

Conditions are expected to escalate rapidly, with Kp levels forecast to hit 5.67 (G2) by 21:00 UTC. Following this brief spike, activity will likely subside to Kp 3.0 by 00:00 UTC on May 17th.

🌌 Aurora Outlook

Aurora observers at high latitudes should be prepared for potential visibility between 18:00 and 00:00 UTC. Mid-latitude observers should remain alert for a brief, windowed opportunity for display during the G2 peak, though conditions are not expected to support widespread sightings.

Region Location Class Flares C/M/X
AR4436 N19W26 Cao/B 1/0/0
AR4438 N21W70 Dao/B 0/0/0
2026-05-16 11:56:00.190Space Weather Message Code: WARK04
2026-05-16 08:59:25.577Space Weather Message Code: ALTK05
2026-05-16 08:45:26.043Space Weather Message Code: WARK05
2026-05-16 05:56:54.433Space Weather Message Code: ALTK05
2026-05-15 23:56:11.853Space Weather Message Code: WARK05

Monitor the Kp index for a sustained rise between 18:00 and 21:00 UTC, which will confirm the arrival of the predicted geomagnetic disturbance.