 roduct: 3-Day Forecast
:Issued: 2026 Aug 13 0030 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Aug 13-Aug 15 2026 is 4.00 (below NOAA
Scale levels).
NOAA Kp index breakdown Aug 13-Aug 15 2026
Aug 13 Aug 14 Aug 15
00-03UT 2.00 3.67 3.67
03-06UT 1.67 3.33 3.33
06-09UT 1.33 3.00 3.00
09-12UT 1.00 2.67 3.00
12-15UT 1.33 3.00 2.33
15-18UT 1.67 3.33 2.67
18-21UT 1.67 3.33 3.00
21-00UT 3.00 4.00 3.00
Rationale: No G1 (Minor) or greater geomagnetic storms are expected.
Unsettled to active levels are expected on 14-15 Aug due to CH HSS
effects.
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 Aug 13-Aug 15 2026
Aug 13 Aug 14 Aug 15
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 Aug 13-Aug 15 2026
Aug 13 Aug 14 Aug 15
R1-R2 10% 15% 15%
R3 or greater 1% 1% 1%
Rationale: Solar activity is expected to be low to very low 13-15 Aug,
though there is an increasing but slight chance for M-class
(R1-R2/Minor-Moderate) flares, primarily driven by the development
observed in Regions 4503 and 4507.
--- MBSE BBS v1.1.7.2 (Linux-x86_64)
* Origin: Outpost BBS * Johnson City, TN (618:618/1)
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