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| Warnings and Alerts | |
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Issue Time: 2026 Sep 16 0538 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5417 Valid From: 2026 Sep 15 1849 UTC Now Valid Until: 2026 Sep 16 1800 UTC Warning Condition: Persistence Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Space Weather Scales |
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| Current Condition and Alerts | |
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Issued: 2026 Sep 16 1205 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Geophysical Alert Message Solar-terrestrial indices for 15 September follow. Solar flux 107 and estimated planetary A-index 8. The estimated planetary K-index at 1200 UTC on 16 September was 1.67. No space weather storms were observed for the past 24 hours. Space weather for the next 24 hours is predicted to be minor. Geomagnetic storms reaching the G1 level are likely. Space Weather Scales |
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| Forecast Discussion | |
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Issued: 2026 Sep 16 1230 UTC
Prepared
by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction
Center
Solar Activity .24 hr Summary... Solar activity continued at very low levels with occasional B-class flaring from unnumbered plage regions. There are two numbered sunspot regions on the visible disk that are both stable unipolar groups. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to remain at very low levels, with a chance for isolated C-class flares through 18 Sep. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at moderate levels, with a peak flux of 427 pfu observed at 15/1710 UTC. The greater than 10 MeV proton flux remained at background levels. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels through 18 Sep. The greater than 10 MeV proton flux is anticipated to remain at background levels through 18 Sep. Solar Wind .24 hr Summary... Solar wind parameters were enhanced, likely from transient CME features followed by weak negative polarity coronal hole high-speed stream (-CH HSS) onset. Total field strength (Bt) reached a peak of 16-17 nT near 15/1700 UTC before gradually declining to 3-5 nT late in the period. The Bz component was mostly southward between 15/1830 UTC and 16/0000 UTC and reached a maximum southward deflection of -13 nT. Two brief intervals of enhanced solar wind speed, reaching near 800 km/s, were observed near 15/1145 UTC and 15/1830 UTC. Speeds subsequently subsided to between 500 and 550 km/s late in the period. The phi angle was predominantly negative (towards the Sun). .Forecast... Negative polarity CH HSS effects are anticipated to persist through 18 Sep. Additional enhancements are likely on 16 and 17 Sep due to flanking influences from CMEs that departed the Sun on 13 and 14 Sep. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels. .Forecast... Geomagnetic activity is expected to reach active to G1 (Minor) storm levels on 16 and 17 Sep due to combined CH and CME influences. Unsettled to active conditions are likely on 18 Sep as enhancements wane. Space Weather Scales |
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| Three Day Forecast | |
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Issued: 2026 Sep 16 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 4 (below NOAA Scale levels). The greatest expected 3 hr Kp for Sep 16-Sep 18 2026 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Sep 16-Sep 18 2026 Sep 16 Sep 17 Sep 18 00-03UT 3.67 4.00 3.67 03-06UT 3.00 4.67 (G1) 2.00 06-09UT 2.33 3.67 2.00 09-12UT 1.67 3.33 2.67 12-15UT 3.00 3.33 2.67 15-18UT 3.33 3.33 2.67 18-21UT 3.67 3.33 2.67 21-00UT 4.67 (G1) 3.33 3.00 Rationale: Active to G1 (Minor) geomagnetic storm conditions are expected on 16 and 17 Sep due to combined negative polarity CH HSS and CME influences. Unsettled to active levels are likely on 18 Sep as enhancements wane. 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 16-Sep 18 2026 Sep 16 Sep 17 Sep 18 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 16-Sep 18 2026 Sep 16 Sep 17 Sep 18 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. Space Weather Scales |
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| Weekly Highlights and Forecasts | |
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Issued: 2026 Sep 14 0117 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Highlights of Solar and Geomagnetic Activity 07 - 13 September 2026 Solar activity was at low levels for 07-10 Sep and 12-13 Sep, and was at very low levels on 11 Sep. The largest flare of the period was a C5.8/Sf at 12/1720 UTC from Region 4521 (N09, L=266, class/area Hsx/90 on 06 Sep). This region was responsible for the majority of the C-flaring activity, producing 6 of the observed 15. The remainder were produced by Regions 4524 (N12, L=225, class/area Cao/100 on 06 Sep) and 4528 (S11, L=187, class/area Hsx/120 on 08 Sep). There were 4 CMEs this period. 3 of these were due to filament eruptions. First was a filament eruption associated with a C3.4/1f at 09/0908 UTC from Region 4524, whose slow CME first became visible in STEREO coronagraph imagery at ~09/1623 UTC and in LASCO C3 at ~09/2106 UTC. Modeling indicated a possible glancing blow on 14 Sep. Second, a filament centered around approximately S15W30 began erupting at ~10/0330 UTC, with an associated slow CME first becoming visible in LASCO C2 at ~10/0524 UTC and GOES CCOR1 at ~10/0730 UTC. Modeling indicated the majority of the material would likely pass ahead and below of Earth orbit, however there was the potential for this eruption also produce a very minor glancing blow on 14 Sep. Third was an 8 degree long filament at roughly disk center that began erupting at ~13/1900 UTC, producing a long duration C1.4 at 13/1945 UTC and an associated CME that first became visible in LASCO C2 at ~13/1948 UTC and SOLAR1 CCOR2 at ~13/2030 UTC. Modeling indicated a possible glancing blow on 17 Sep. Lastly, a very slow CME first became visible in LASCO C2 at ~12/1612 UTC and in STEREO at ~12/1638 UTC. Despite triangulation with STEREO indicating a front-sided eruption, no clear source was found except for perhaps some faint coronal dimming in the SW quadrant in GOES/SUVI 195. Modeling indicated the material would pass below Earth orbit. The greater than 10 MeV proton flux at geosynchronous orbit was slightly elevated on 07 Sep due to the continued recovery from the 05 Sep S1 event, but was at background levels for the majority of the reporting period. The greater than 2 MeV electron flux at geosynchronous orbit was at normal-moderate levels on 07 Sep and at high levels on 08-13 Sep. Geomagnetic activity reached active levels and a few isolated periods of G1 (Minor) storming conditions on 08 Sep due to positive polarity coronal hole high speed stream (CH HSS) influences, potentially with embedded effects from CMEs that left the Sun on either 04 Sep or 06 Sep. The remainder of the reporting period, 09-13 Sep, was at quiet to unsettled levels. Forecast of Solar and Geomagnetic Activity 14 September - 10 October 2026 Solar activity is expected to be at low levels, with a slight chance for moderate to high levels throughout the forecast period. Not proton events are expected at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 14 Sep, 16-23 Sep, 27 Sep-03 Oct, and 05-10 Oct. Levels are expected to be at normal-moderate levels on 15 Sep, 24-16 Sep, and 04 Oct. Geomagnetic field activity is expected to reach active to G1 storming levels on 14-17 Sep due to negative polarity CH HSS effects with the potential for CME influence from a CME that left the Sun on 09 Sep; 24-27 Sep due to positive polarity CH HSS influences; and unsettled to active levels on 05-08 Oct due to positive polarity CH HSS influences. Largely quiet levels are anticipated for all remaining dates in the forecast period. Space Weather Scales |
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| About AIA Images | |
| The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) is designed to provide an unprecedented view of the solar corona, taking images that span at least 1.3 solar diameters in multiple wavelengths nearly simultaneously, at a resolution of ~ 1 arcsec and at a cadence of 10 s or better. The primary goal of the AIA Science Investigation is to use these data, together with data from other SDO instruments and from other observatories, to significantly improve our understanding of the physics behind the activity displayed by the Sun's atmosphere, which drives space weather in the heliosphere and in planetary environments. The AIA will produce data required for quantitative studies of the evolving coronal magnetic field, and the plasma that it holds, both in quiescent phases and during flares and eruptions; the AIA science investigation aims to utilize these data in a comprehensive research program to provide new understanding of the observed processes Left Click Image for screen size, Right Click Image and open in new tab for full size. | |
| Daily Image AIA 171 | |
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| Daily Image AIA 171 PFSS Model | |
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| Daily Image AIA 193 | |
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| Daily Image AIA 304 | |
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| Daily Video AIA 171 | |
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| Daily Video AIA 171 PFSS Model | |
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| Daily Video AIA 193 | |
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| Daily Video AIA 304 | |
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| About the HMI Images | |
| (Helioseismic and Magnetic Imager) HMI is an instrument designed to study oscillations and the magnetic field at the solar surface, or photosphere. HMI is one of three instruments on the Solar Dynamics Observatory; together, the suite of instruments observes the Sun nearly continuously and takes a terabyte of data a day. HMI observes the full solar disk at 6173 Å with a resolution of 1 arcsecond. HMI is a successor to the Michelson Doppler Imager on the Solar and Heliospheric Observatory. This is very much how the Sun looks like in the visible range of the spectrum (for example, looking at it using special 'eclipse' glasses: Remember, do not ever look directly at the Sun!). The magnetogram image shows the magnetic field in the solar photosphere, with black and white indicating opposite polarities. Left Click Image for screen size, Right Click Image and open in new tab for full size. | |
| Daily Image HMI Continuum | |
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| Daily Image HMI Magnetogram | |
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| Daily Video HMI Continuum | |
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| Daily Video HMI Magnetogram | |
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| About LASCO Images | |
| LASCO (Large Angle Spectrometric Coronagraph) is able to take images of the solar corona by blocking the light coming directly from the Sun with an occulter disk, creating an artificial eclipse within the instrument itself. The position of the solar disk is indicated in the images by the white circle. The most prominent feature of the corona are usually the coronal streamers, those nearly radial bands that can be seen both in C2 and C3. Occasionally, a coronal mass ejection can be seen being expelled away from the Sun and crossing the fields of view of both coronagraphs. The shadow crossing from the lower left corner to the center of the image is the support for the occulter disk. C2 images show the inner solar corona up to 8.4 million kilometers (5.25 million miles) away from the Sun. C3 images have a larger field of view: They encompass 32 diameters of the Sun. To put this in perspective, the diameter of the images is 45 million kilometers (about 30 million miles) at the distance of the Sun, or half of the diameter of the orbit of Mercury. Many bright stars can be seen behind the Sun. Left Click Image for screen size, Right Click Image and open in new tab for full size. | |
| Combined C2 C3 and AIA 304 | |
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| Log Polar View C2 C3 and AIA 304 | |
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| Combined C2 C3 and AIA 304 Video | |
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| Log Polar View C2 C3 and AIA 304 Video | |
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| Space Weather Videos | |
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| Space Weather Information | |
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Demystifying Space Weather An article by Scientific Frontline Informative information and glossary about “Space Weather” Space weather has become increasingly important in our modern world due to our growing reliance on technology. It can impact various aspects of our daily lives, from communication and navigation systems to power grids and even astronaut safety. In this deep dive, we'll explore the intricacies of space weather, its causes, its effects, and why understanding it is crucial in our technology-dependent society. |
