####018002400####
FXXX10 KWNP 111841

DAYTDF



:Product: 3-Day Forecast

:Issued: 2025 Nov 11 1840 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 Nov 11-Nov 13 2025 is 7.33 (NOAA Scale

G3).



NOAA Kp index breakdown Nov 11-Nov 13 2025



             Nov 11       Nov 12       Nov 13

00-03UT       2.33         5.00 (G1)    6.67 (G3)     

03-06UT       2.67         7.33 (G3)    6.33 (G2)

06-09UT       1.67         6.00 (G2)    6.00 (G2)    

09-12UT       2.33         4.67 (G1)    4.67 (G1)     

12-15UT       0.33         4.33         4.00     

15-18UT       0.67         8.00 (G4)    3.33     

18-21UT       1.33         7.67 (G4)    4.33     

21-00UT       5.67 (G2)    7.00 (G3)    4.67 (G1)     



Rationale: (UPDATE) CME activity from 09-11 Nov is likely to cause G2

(Moderate) levels late on 11 Nov, G1-G4 (Minor-Severe) levels on 12 Nov,

and G1-G3 (Minor-Strong) storm levels on 13 Nov.



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 Nov 11-Nov 13 2025



              Nov 11  Nov 12  Nov 13

S1 or greater   99%     75%     65%



Rationale: The greater than 10 MeV proton flux is expected to continue

above the S1 (Minor) threshold through 12 Nov, with S2 levels possible

through 12 Nov. Further enhancements are possible with the arrival of

the 09-11 Nov CMEs on 11 and 12 Nov.



C. NOAA Radio Blackout Activity and Forecast



Radio blackouts reaching the R3 levels were observed over the past 24

hours. The largest was at Nov 11 2025 1004 UTC.



Radio Blackout Forecast for Nov 11-Nov 13 2025



              Nov 11        Nov 12        Nov 13

R1-R2           85%           85%           85%

R3 or greater   55%           55%           55%



Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected, with

further R3 (Strong) activity likely on 11-13 Nov due to the flare

potential of Region 4274.