Solar Information
Solar images from SOHO
The Sun Now

Extreme ultraviolet Imaging Telescope image at 284 Angstrom (to 2 million degrees K)

Michelson Doppler Imager (MDI) image showing sunspots

Magnetogram image showing magnetic field, black and white show opposite polarities
Information from the Space Weather Prediction Center, Boulder, CO
National Oceanic and Atmospheric Administration (NOAA)
Aurora Activity
Solar Cycle
Solar Wind
3-day Solar-Geophysical Forecast
:Product: 3-Day Forecast
:Issued: 2026 Apr 16 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
A. NOAA Geomagnetic Activity Observation and Forecast
The greatest observed 3 hr Kp over the past 24 hours was 2 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 16-Apr 18 2026 is 6.00 (NOAA Scale
G2).
NOAA Kp index breakdown Apr 16-Apr 18 2026
Apr 16 Apr 17 Apr 18
00-03UT 0.67 2.33 6.00 (G2)
03-06UT 1.00 2.67 6.00 (G2)
06-09UT 1.00 2.67 5.00 (G1)
09-12UT 0.67 2.00 4.00
12-15UT 1.67 1.33 3.67
15-18UT 1.67 2.67 3.33
18-21UT 1.67 4.33 3.00
21-00UT 2.33 5.67 (G2) 4.33
Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 17-18
Apr due to the anticipated arrival of a negative polarity CH HSS CIR.
B. NOAA Solar Radiation Activity Observation and Forecast
Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was
below S-scale storm level thresholds.
Solar Radiation Storm Forecast for Apr 16-Apr 18 2026
Apr 16 Apr 17 Apr 18
S1 or greater 1% 1% 1%
Rationale: No S1 (Minor) or greater solar radiation storms are expected.
No significant active region activity favorable for radiation storm
production is forecast.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Apr 16-Apr 18 2026
Apr 16 Apr 17 Apr 18
R1-R2 30% 30% 30%
R3 or greater 5% 5% 5%
Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
through 18 Apr, mostly due to the flare potential of Region 4419.





