154
FXXX10 KWNP 120031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 May 12 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 5 (NOAA Scale
G1).
The greatest expected 3 hr Kp for May 12-May 14 2025 is 4.67 (NOAA Scale
G1).

NOAA Kp index breakdown May 12-May 14 2025

             May 12       May 13       May 14
00-03UT       4.00         2.67         2.33
03-06UT       4.67 (G1)    3.67         2.67
06-09UT       3.33         2.67         2.33
09-12UT       3.00         2.67         2.33
12-15UT       2.67         1.67         2.67
15-18UT       3.67         1.67         2.33
18-21UT       2.67         3.00         2.33
21-00UT       2.67         2.67         2.00

Rationale: An isolated period of G1 (Minor) conditions are expected on
12 May as negative polarity CH HSS influences linger yet diminish.

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 12-May 14 2025

              May 12  May 13  May 14
S1 or greater    1%      1%      1%

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

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at May 12 2025 0001 UTC.

Radio Blackout Forecast for May 12-May 14 2025

              May 12        May 13        May 14
R1-R2            1%            1%            1%
R3 or greater    1%            1%            1%

Rationale: No R1 (Minor) or greater radio blackouts are expected.  No
significant active region flare activity is forecast.