884
FXXX10 KWNP 210031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Jan 21 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 8 (NOAA Scale
G4).
The greatest expected 3 hr Kp for Jan 21-Jan 23 2026 is 6.67 (NOAA Scale
G3).

NOAA Kp index breakdown Jan 21-Jan 23 2026

             Jan 21       Jan 22       Jan 23
00-03UT       6.67 (G3)    4.00         2.67
03-06UT       6.67 (G3)    3.33         2.67
06-09UT       5.67 (G2)    3.00         2.33
09-12UT       5.67 (G2)    2.67         2.33
12-15UT       4.67 (G1)    3.00         2.33
15-18UT       4.67 (G1)    3.00         2.33
18-21UT       3.67         3.33         2.33
21-00UT       3.67         3.67         2.00

Rationale: G1-G3 (Minor-Strong) geomagnetic storms are anticipated on
20-21 Jan due to continuing CH HSS influence and the passage of a halo
CME that arrived late on 19 Jan.

B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was
above S-scale storm level thresholds.

Solar Radiation Storm Forecast for Jan 21-Jan 23 2026

              Jan 21  Jan 22  Jan 23
S1 or greater   99%     45%     15%

Rationale: S1 (Minor) or greater solar radiation storms are expected to
continue through 21 Jan, with the possibility of another crossing or
slow decay keeping 22-23 Jan probabilities elevated.

C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Jan 21-Jan 23 2026

              Jan 21        Jan 22        Jan 23
R1-R2           60%           60%           60%
R3 or greater   15%           15%           15%

Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a
slight chance for R3 (Strong) events, on 21-23 Jan.