Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
923
FXXX10 KWNP 040031
DAYTDF
:Product: 3-Day Forecast
:Issued: 2025 Dec 04 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 7 (NOAA Scale
G3).
The greatest expected 3 hr Kp for Dec 04-Dec 06 2025 is 5.67 (NOAA Scale
G2).
NOAA Kp index breakdown Dec 04-Dec 06 2025
Dec 04 Dec 05 Dec 06
00-03UT 4.67 (G1) 4.33 3.67
03-06UT 4.67 (G1) 4.33 2.00
06-09UT 5.67 (G2) 4.33 2.00
09-12UT 4.33 4.00 2.67
12-15UT 3.67 3.67 2.67
15-18UT 3.67 3.33 2.67
18-21UT 4.00 3.00 2.67
21-00UT 4.33 3.33 3.00
Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 04
Dec due to combined CH HSS and embedded CME 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 04-Dec 06 2025
Dec 04 Dec 05 Dec 06
S1 or greater 15% 15% 15%
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 04-Dec 06 2025
Dec 04 Dec 05 Dec 06
R1-R2 75% 75% 75%
R3 or greater 30% 30% 30%
Rationale: Isolated to occasional R1-R2 (Minor-Moderate) radio blackouts
are expected (75%) through 06 Dec, with a chance for a R3 (Strong) event
(30%), given past flare history and the potential of current active
regions on the disk.