990
FXXX10 KWNP 190031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2024 May 19 0030 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/wwire.html
#
#             3-Day Forecast
#
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 4.67 (NOAA Scale
G1).

NOAA Kp index breakdown May 19-May 21 2024

             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.