521
FXXX10 KWNP 110031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Oct 11 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 Oct 11-Oct 13 2025 is 5.00 (NOAA Scale
G1).

NOAA Kp index breakdown Oct 11-Oct 13 2025

             Oct 11       Oct 12       Oct 13
00-03UT       2.33         3.00         3.67
03-06UT       2.00         3.00         3.00
06-09UT       2.33         3.67         3.00
09-12UT       2.33         4.67 (G1)    4.67 (G1)
12-15UT       3.00         3.00         3.00
15-18UT       3.33         3.67         2.00
18-21UT       3.67         5.00 (G1)    2.67
21-00UT       4.00         3.67         3.67

Rationale: Periods of G1 (Minor) geomagnetic storms are likely on 12-13
Oct in response to negative polarity CH HSS influences.

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 Oct 11-Oct 13 2025

              Oct 11  Oct 12  Oct 13
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

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Oct 11-Oct 13 2025

              Oct 11        Oct 12        Oct 13
R1-R2           15%           15%           15%
R3 or greater    1%            1%            1%

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