379
FXXX10 KWNP 011231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Oct 01 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 6 (NOAA Scale
G2).
The greatest expected 3 hr Kp for Oct 01-Oct 03 2025 is 5.67 (NOAA Scale
G2).

NOAA Kp index breakdown Oct 01-Oct 03 2025

             Oct 01       Oct 02       Oct 03
00-03UT       5.33 (G1)    3.33         3.00
03-06UT       5.33 (G1)    3.00         3.00
06-09UT       4.67 (G1)    3.00         2.67
09-12UT       3.67         3.67         3.00
12-15UT       4.67 (G1)    3.00         3.00
15-18UT       3.67         3.00         3.67
18-21UT       4.00         3.33         3.00
21-00UT       5.67 (G2)    3.67         2.00

Rationale: G2 (Moderate) geomagnetic storms are likely due to 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 01-Oct 03 2025

              Oct 01  Oct 02  Oct 03
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

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Sep 30 2025 1230 UTC.

Radio Blackout Forecast for Oct 01-Oct 03 2025

              Oct 01        Oct 02        Oct 03
R1-R2           60%           60%           60%
R3 or greater   15%           15%           15%

Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely with slight
chances for isolated R3 stronger events.