994
FXXX10 KWNP 241231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Dec 24 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 Dec 24-Dec 26 2025 is 4.67 (NOAA Scale
G1).

NOAA Kp index breakdown Dec 24-Dec 26 2025

             Dec 24       Dec 25       Dec 26
00-03UT       4.33         3.67         2.00
03-06UT       4.33         2.67         2.67
06-09UT       3.67         2.67         2.33
09-12UT       2.67         3.00         2.33
12-15UT       4.67 (G1)    2.67         2.33
15-18UT       3.33         1.67         2.33
18-21UT       3.00         1.67         2.33
21-00UT       3.67         2.67         2.67

Rationale: G1 (Minor) or greater geomagnetic storms are expected on 24
Dec due to persistent 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 Dec 24-Dec 26 2025

              Dec 24  Dec 25  Dec 26
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 Dec 24-Dec 26 2025

              Dec 24        Dec 25        Dec 26
R1-R2           30%           40%           45%
R3 or greater    5%            5%            5%

Rationale: There is an increasing chance for R1-R2 (Minor-Moderate)
radio blackouts through 26 Dec.