Tempêtes magnétiques aujourd'hui

NOAA SWPC 3-Day Forecast

:Product: 3-Day Forecast
:Issued: 2026 Sep 14 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
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 14-Sep 16 2026 is 4.67 (NOAA Scale
G1).

NOAA Kp index breakdown Sep 14-Sep 16 2026

             Sep 14       Sep 15       Sep 16
00-03UT       1.00         3.33         3.67     
03-06UT       2.33         3.67         3.33     
06-09UT       1.33         3.33         3.00     
09-12UT       2.00         3.33         2.67     
12-15UT       3.67         3.00         3.00     
15-18UT       3.33         2.00         3.33     
18-21UT       3.67         3.00         3.67     
21-00UT       3.33         3.00         4.67 (G1)

Rationale: The likelihood of G1 storming increases on 16 Sep as a
subsequent -CH HSS moves into a geoeffective position.

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 14-Sep 16 2026

              Sep 14  Sep 15  Sep 16
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 Sep 14-Sep 16 2026

              Sep 14        Sep 15        Sep 16
R1-R2            5%            5%            5%
R3 or greater    1%            1%            1%

Rationale: No R1 (Minor) or greater radio blackouts are expected.  No
significant active region flare activity is forecast.