Product: 3-Day Forecast
- Issued: 2026 Aug 27 0030 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center.
Geomagnetic Activity Observation and Forecast
The greatest observed 3 hr Kp over the past 24 hours was 1 (below NOAA Scale levels). The greatest expected 3 hr Kp for Aug 27-Aug 29 2026 is 5.67 (NOAA Scale G2).
| Aug 27 | Aug 28 | Aug 29 | |
|---|---|---|---|
| 00-03UT | 1.33 | 5.67 (G2) | 5.67 (G2) |
| 03-06UT | 2.33 | 4.67 (G1) | 4.67 (G1) |
| 06-09UT | 3.33 | 4.00 | 4.00 |
| 09-12UT | 3.00 | 4.00 | 3.00 |
| 12-15UT | 3.33 | 3.67 | 3.33 |
| 15-18UT | 3.67 | 4.00 | 2.67 |
| 18-21UT | 4.33 | 4.00 | 2.67 |
| 21-00UT | 4.67 (G1) | 4.67 (G1) | 2.67 |
Rationale: Isolated G1-G2 (Minor-Moderate) geomagnetic storms are likely through 29 Aug due to both CH HSS and CME arrival influences.
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.
| Aug 27 | Aug 28 | Aug 29 | |
|---|---|---|---|
| S1 or greater | 10% | 10% | 10% |
Rationale: There is a slight chance for S1 (Minor) or greater solar radiation storms all three days.
Radio Blackout Activity and Forecast
Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Aug 26 2026 0634 UTC.
| Aug 27 | Aug 28 | Aug 29 | |
|---|---|---|---|
| R1-R2 | 55% | 55% | 55% |
| R3 or greater | 15% | 15% | 15% |
Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts and a slight chance for R3 (Strong) or greater blackouts all three days.
Space Weather Overview
Credits
Space Weather Images and Information (excluded from copyright) courtesy of:
NOAA / NWS Space Weather Prediction Center
Mauna Loa Solar Observatory (HAO/NCAR)
SOHO (ESA & NASA)
Powered by Space Weather PHP script by Mike Challis of Long Beach Weather.
Additions by Ken True of Saratoga Weather and Jerry Wilkins of Southeast Lincoln Weather.