Product: 3-Day Forecast - Issued: 2026 Jul 05 1230 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center.

Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 6 (NOAA Scale G2). The greatest expected 3 hr Kp for Jul 05-Jul 07 2026 is 4.67 (NOAA Scale G1).

Rationale: Influence from the 01-02 Jul CME arrival is anticipated on 05-06 Jul, coupled with possible influence from +CH72. G1 (Minor) levels are likely, on 05-06 Jul, with an isolated period of G2 (Moderate) possible.

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.

Rationale: There is a slight chance for a greater than 10 MeV proton event (S1-Minor) on 05-06 Jul due to the recent and potential flare activity of Regions 4478 and 4479.

Radio Blackout Activity and Forecast

Radio blackouts reaching the R3 levels were observed over the past 24 hours. The largest was at Jul 04 2026 2041 UTC.

Rationale: Solar activity is expected to remain at R1-R2 (Minor-Moderate) levels, with a slight chance for R3 (Strong) events through 05 Jul. As Regions 4479 and 4480 rotate around the west limb by 06 Jul, activity is expected to begin decreasing, but moderate levels are likely to persist until these regions rotate another day beyond the limb. Activity should decrease to a slight chance for R1-R2 (Minor-Moderate) levels on 07 Jul as these regions complete their transit of the limb.