396
FXXX10 KWNP 070031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Sep 07 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 2 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Sep 07-Sep 09 2026 is 4.67 (NOAA Scale
G1).

NOAA Kp index breakdown Sep 07-Sep 09 2026

             Sep 07       Sep 08       Sep 09
00-03UT       3.33         4.00         3.00
03-06UT       2.00         4.00         2.67
06-09UT       2.00         4.67 (G1)    2.33
09-12UT       3.00         4.67 (G1)    2.33
12-15UT       3.00         4.67 (G1)    2.00
15-18UT       3.33         4.00         2.00
18-21UT       3.67         3.67         2.00
21-00UT       4.00         3.33         2.33

Rationale: G1 (Minor) geomagnetic storming conditions are expected on 08
Sep with the anticipated arrival of several CMEs from 02 and 05 Sep
embedded in a high speed stream.

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 Sep 07-Sep 09 2026

              Sep 07  Sep 08  Sep 09
S1 or greater   10%     10%     10%

Rationale: There is a slight chance for S1 (Minor) or greater solar
radiation storms through 09 Sep.

C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Sep 07-Sep 09 2026

              Sep 07        Sep 08        Sep 09
R1-R2           20%           20%           20%
R3 or greater    1%            1%            1%

Rationale: There is a slight chance for R1-R2 (Minor-Moderate) radio
blackouts through 09 Sep.