3-Day Forecast

Issued: 2024 May 19 0030 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 4 (below NOAA Scale levels).

The greatest expected 3 hr Kp for May 19-May 21 2024 is 4 (.67NOAA scale G1).

NOAA Kp index breakdown

             May 19       May 20       May 21
00-03UT       2.00         3.67         4.00     
03-06UT       2.33         3.33         3.67     
06-09UT       2.67         2.33         3.00     
09-12UT       4.00         2.33         2.67     
12-15UT       4.00         4.67 (G1)    3.00     
15-18UT       3.67         4.67 (G1)    2.67     
18-21UT       3.67         4.00         2.67     
21-00UT       3.33         4.00         2.67     

Rationale

G1 (Minor) geomagnetic storms are likely on 20 May due to weak CME arrival glancing blow potential.

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 May 19-May 21 2024

              May 19  May 20  May 21
S1 or greater   10%     10%     10%

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 May 19-May 21 2024

              May 19        May 20        May 21
R1-R2           55%           55%           55%
R3 or greater   25%           25%           25%

Rationale

R1-R2 (Minor-Moderate) radio blackouts are likely 19-21 May due to the number of active regions present on the visible solar disk and total flare probability contributions.