3-Day Forecast

Issued: 2026 Jun 05 1230 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center and processed by SpaceWeatherLive.com

A. NOAA Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 3 (below NOAA Scale levels).

The greatest expected 3 hr Kp for Jun 05-Jun 07 2026 is 6 (.67NOAA scale G3).

NOAA Kp index breakdown

             Jun 05       Jun 06       Jun 07
00-03UT       1.33         4.33         3.00     
03-06UT       3.33         4.00         3.00     
06-09UT       2.00         4.00         2.00     
09-12UT       2.33         3.00         2.67     
12-15UT       6.67 (G3)    2.33         2.67     
15-18UT       5.67 (G2)    2.67         2.67     
18-21UT       4.67 (G1)    3.33         2.00     
21-00UT       3.67         3.67         2.67     

Rationale

Periods of G1-G3 (Minor-Strong) geomagnetic storming are likely on 05 Jun, with a chance for G4 (Severe) storm periods, due to the anticipated arrival of multiple CMEs that left the Sun on 03 Jun.

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 Jun 05-Jun 07 2026

              Jun 05  Jun 06  Jun 07
S1 or greater    5%      5%      5%

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 Jun 05-Jun 07 2026

              Jun 05        Jun 06        Jun 07
R1-R2           50%           50%           50%
R3 or greater   10%           10%           10%

Rationale

There is a chance for R1-R2 (Minor-Moderate) radio blackouts, with a slight chance for R3 (Strong) or greater events, over 05-07 Jun.