| Warnings | |
|
Issue Time: 2025 Sep 17 0459 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3525 Begin Time: 2025 Sep 16 1100 UTC Yesterday Maximum 2MeV Flux: 3347 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. Space Weather Scales |
|
| Current Condition and Alerts | |
|
Issued: 2025 Sep 17 1205 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Geophysical Alert Message Solar-terrestrial indices for 16 September follow. Solar flux 135 and estimated planetary A-index 21. The estimated planetary K-index at 1200 UTC on 17 September was 3.33. No space weather storms were observed for the past 24 hours. No space weather storms are predicted for the next 24 hours. Space Weather Scales |
|
| Forecast Discussion | |
|
Issued: 2025 Sep 17 1230 UTC
Prepared
by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction
Center
Solar Activity .24 hr Summary... Solar activity was low. Low level C-class flares were observed from Regions 4217 (S16E40, Eao/beta), 4220 (S18E08, Cro/beta), and 4223 (S17E56, Cro/beta). Slight growth was observed in Regions 4220, 4221 (N04E37, Cso/beta), and new Region 4224 (S09E37, Bxo/beta). New Regions 4223 and 4225 (N10E74, Hsx/alpha) rotated onto the E limb and were numbered. The rest of the spot groups were either stable or in decay. No Earth-directed CMEs were observed. .Forecast... Solar activity is expected to be low, with a chance for an isolated M-flare (R1-R2/Minor-Moderate), through 19 Sep. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 3,350 pfu observed at 16/1525 UTC. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to continue at moderate to high levels through 19 Sep. The greater than 10 MeV proton flux is expected to persist at background levels. Solar Wind .24 hr Summary... Solar wind parameters continued to be enhanced under a negative polarity CH HSS. Solar wind speed ranged from approximately 635-815 km/s. Total field was steady between 4-6 nT while the Bz component ranged from +/-5 nT. Phi angle was mostly negative. .Forecast... Solar wind parameters are expected to continue under the influence of a negative polarity CH HSS. Solar wind speed is likely to gradually diminish on 17-18 Sep. A return to nominal solar wind conditions is expected by 19 Sep. Geospace .24 hr Summary... The geomagnetic field reached quiet to active levels due to CH HSS effects. .Forecast... Unsettled to active conditions, with a chance for G1 (Minor) storming, is expected on 17 Sep. Quiet to unsettled levels are expected on 18 Sep as HSS conditions gradually diminish. A return to mostly quiet levels is expected by 19 Sep. Space Weather Scales |
|
| Three Day Forecast | |
|
Issued: 2025 Sep 17 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 17-Sep 19 2025 is 3.33 (below NOAA Scale levels). NOAA Kp index breakdown Sep 17-Sep 19 2025 Sep 17 Sep 18 Sep 19 00-03UT 2.33 2.33 1.67 03-06UT 2.67 3.00 1.33 06-09UT 3.33 3.00 1.33 09-12UT 3.33 2.33 1.33 12-15UT 1.67 1.67 1.33 15-18UT 1.67 1.67 1.33 18-21UT 2.33 2.00 1.67 21-00UT 2.67 2.33 1.67 Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No significant transient or recurrent solar wind features are forecast. 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 17-Sep 19 2025 Sep 17 Sep 18 Sep 19 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 17-Sep 19 2025 Sep 17 Sep 18 Sep 19 R1-R2 30% 30% 30% R3 or greater 1% 1% 1% Rationale: There is a chance for isolated R1-R2 (Minor-Moderate) radio blackouts through 19 Sep. Space Weather Scales |
|
| Weekly Highlights and Forecasts | |
|
Issued: 2025 Sep 15 0137 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Highlights of Solar and Geomagnetic Activity 08 - 14 September 2025 Solar activity was at low levels with only C-Class flares observed. The largest flare of the period was a C7.6 from Region 4207 (N28, L=48, class/area=Cso/80 on 11 Sep) at 11/1521 UTC. No significant CME activity was observed. No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 09, 13, and 14 Sep due to influences from multiple coronal hole high speed streams (CH HSS). Normal to moderate levels were observed on 08, 10, 11, and 12 Sep. Geomagnetic field activity reached G2 (Moderate) storm levels on 09 Sep due to sustained period of southward Bz. G1 (Minor) storm levels were observed on 14 Sep due to influences from a negative polarity CH HSS. Quiet to active levels were observed on the remaining days of the highlight period. Forecast of Solar and Geomagnetic Activity 15 September - 11 October 2025 Solar activity is expected to be at low levels with a chance for isolated M-class flares throughout the outlook period. No proton events are expected at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 18-21 Sep and 06-11 Oct due to recurrent CH HSS influences. Normal to moderate levels are expected for the remainder of the outlook period. Geomagnetic field activity is expected to be at G2 (Moderate) storm levels on 15 Sep due to influences from negative polarity CH HSS. Active to G1 (Minor) storm levels are expected on 16 Sep, 28-29 Sep, 03-07 Oct, and 11 Oct all due to recurrent CH HSS influences. Quiet to unsettled levels are expected for the remaining days in the outlook period. Space Weather Scales |
|
| 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 | |
 |
|
| Daily Image AIA 171 PFSS Model | |
| Currently No Data AIA 171 PFSS Channel | Region of atmosphere | Primary ion(s) 171Å | quiet corona, upper transition region | Fe IX | |
| Daily Image AIA 193 | |
 |
|
| Daily Image AIA 304 | |
 |
|
| Daily Video AIA 171 | |
 |
|
| Daily Video AIA 171 PFSS Model | |
| Currently No Data PFSS Video | |
| Daily Video AIA 193 | |
 |
|
| Daily Video AIA 304 | |
 |
|
| 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 | |
 |
|
| Daily Image HMI Magnetogram | |
 |
|
| 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 | |
 |
|
| Log Polar View C2 C3 and AIA 304 | |
 |
|
| Combined C2 C3 and AIA 304 Video | |
 |
|
| Log Polar View C2 C3 and AIA 304 Video | |
 |
|
| Space Weather Videos | |
|
|
|
| Space Weather Information | |
|
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. |
.jpg)