Product: 3-Day Forecast
- Issued: 2026 Mar 15 1230 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 5 (NOAA Scale G1). The greatest expected 3 hr Kp for Mar 15-Mar 17 2026 is 4.67 (NOAA Scale G1).
| Mar 15 | Mar 16 | Mar 17 | |
|---|---|---|---|
| 00-03UT | 4.00 | 3.67 | 2.67 |
| 03-06UT | 2.00 | 3.67 | 3.00 |
| 06-09UT | 2.33 | 3.00 | 2.33 |
| 09-12UT | 3.67 | 2.33 | 2.33 |
| 12-15UT | 4.67 (G1) | 2.00 | 2.33 |
| 15-18UT | 3.33 | 2.67 | 2.33 |
| 18-21UT | 2.00 | 3.00 | 2.33 |
| 21-00UT | 2.33 | 3.00 | 2.00 |
Rationale: G1 (Minor) geomagnetic storms are likely on 15 Mar due to influence from a positive polarity coronal hole.
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.
| Mar 15 | Mar 16 | Mar 17 | |
|---|---|---|---|
| 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.
Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
| Mar 15 | Mar 16 | Mar 17 | |
|---|---|---|---|
| R1-R2 | 15% | 15% | 15% |
| R3 or greater | 1% | 1% | 1% |
Rationale: There exists a slight chance for R1-R2 (Minor-Moderate) radio blackouts over 15-17 Mar.
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.