736
FXXX10 KWNP 091231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 May 09 1230 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 09-May 11 2025 is 4.67 (NOAA Scale
G1).

NOAA Kp index breakdown May 09-May 11 2025

             May 09       May 10       May 11
00-03UT       2.67         3.67         3.00
03-06UT       2.33         3.00         3.67
06-09UT       1.67         2.67         2.67
09-12UT       2.00         2.00         2.00
12-15UT       2.67         2.67         2.00
15-18UT       3.00         2.00         2.67
18-21UT       3.67         2.67         2.67
21-00UT       4.67 (G1)    2.67         2.67

Rationale: G1 (Minor) geomagnetic storm conditions are likely on 09 May
due to negative polarity CH HSS influences and the possible arrival of a
CME from 05 May.

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 09-May 11 2025

              May 09  May 10  May 11
S1 or greater    5%      5%      5%

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 09-May 11 2025

              May 09        May 10        May 11
R1-R2           40%           40%           40%
R3 or greater    5%            5%            5%

Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
over 09-11 May.