3-Day Forecast

Issued: 2026 Jul 20 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 1 (below NOAA Scale levels).

The greatest expected 3 hr Kp for Jul 20-Jul 22 2026 is 5 (.00NOAA scale G1).

NOAA Kp index breakdown

             Jul 20       Jul 21       Jul 22
00-03UT       0.67         1.33         4.00     
03-06UT       0.67         2.00         4.00     
06-09UT       2.00         2.00         4.00     
09-12UT       1.33         1.33         4.33     
12-15UT       1.67         1.33         5.00 (G1)
15-18UT       0.67         2.33         5.00 (G1)
18-21UT       0.67         3.00         4.67 (G1)
21-00UT       1.33         4.00         4.33     

Rationale

G1 (Minor) geomagnetic storms are expected on 22 Jul due to the anticipated arrival of a CIR ahead of a negative polarity coronal hole high speed stream.

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 Jul 20-Jul 22 2026

              Jul 20  Jul 21  Jul 22
S1 or greater    1%      1%      1%

Rationale

No S1 (Minor) or greater solar radiation storms are expected through 22 Jul.

C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Jul 20-Jul 22 2026

              Jul 20        Jul 21        Jul 22
R1-R2           25%           25%           25%
R3 or greater    1%            1%            1%

Rationale

There is a chance for R1-R2 (Minor-Moderate) radio blackouts through 22 Jul, largely due to the active regions in the northeast.