3-Day Forecast

Issued: 2024 May 19 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 May 19-May 21 2024 is 4 (.67NOAA scale G1).

NOAA Kp index breakdown

             May 19       May 20       May 21
00-03UT       1.33         3.67         4.00     
03-06UT       2.67         3.33         3.67     
06-09UT       1.67         2.33         3.00     
09-12UT       2.33         2.33         2.67     
12-15UT       2.67         4.67 (G1)    3.00     
15-18UT       3.00         4.67 (G1)    2.67     
18-21UT       3.00         4.00         2.67     
21-00UT       3.67         4.00         2.67     

Rationale

G1 (Minor) geomagnetic storms are likely on 20 May due to the arrival of the 17 May CME.

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

There is a slight chance for an S1 (Minor) solar radiation storm on 19-21 May.

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           50%           50%           50%
R3 or greater   10%           10%           10%

Rationale

There is a chance for R1-R2 (Minor-Moderate) radio blackouts on 19-21 May, with a slight chance for R3 (Strong), due primarily to the flare potential of Region 3685.