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| Warnings and Alerts | |
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Issue Time: 2026 Apr 25 0137 UTC
WARNING: Geomagnetic K-index of 4 expected Valid From: 2026 Apr 25 0137 UTC Valid To: 2026 Apr 25 2359 UTC Warning Condition: Onset 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 Apr 25 1205 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Geophysical Alert Message Solar-terrestrial indices for 24 April follow. Solar flux 146 and estimated planetary A-index 9. The estimated planetary K-index at 1200 UTC on 25 April was 0.67. Space weather for the past 24 hours has been moderate. Radio blackouts reaching the R2 level occurred. Space weather for the next 24 hours is predicted to be moderate. Geomagnetic storms reaching the G1 level are likely. Radio blackouts reaching the R2 level are likely. Space Weather Scales |
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| Forecast Discussion | |
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Issued: 2026 Apr 25 1230 UTC
Prepared
by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction
Center
Solar Activity .24 hr Summary... Solar activity was at high levels. Regions 4419 (N17W86, Dso/beta-gamma) and 4423 (S07E22, Dai/beta-delta) were the main contributors to the flare activity. Region 4419 produced the largest flare of the period, an M6.4/1f flare at 24/1815 UTC. Region 4423 added the majority of the flares, including an M1.7/1f flare at 24/1301 UTC, an M1.3/Sf flare at 25/0759 UTC, as well as several C-class flares. Newly numbered Region 4425 (N06E69, Dac/beta-gamma) contributed a couple of C-class flares as well. Initial analysis of the CME associated with the M6.4 flare, mentioned above, indicated most of the ejecta will likely be ahead of and above Earth. Additional modeling is currently underway. There was no indication in available coronagraph imagery of a CME associated with the M1.3 flare that peaked at 25/0759 UTC. There are seven numbered regions on the visible disk. Analysis of Region 4419 is increasingly difficult due to its proximity to the western limb. Region 4420 (N17E03, Fki/beta-gamma-delta) exhibited continued growth, especially in its intermediary spots, and added to its overall length. Region 4423 (S05E22, Dai/beta-delta) continued to evolve, displaying continued shearing and rotation in its trailing spots. Region 4424 (N17E37, Dao/beta) noted initial growth early in the period, but has since stabilized. Region 4425 was also difficult to analyze due to foreshortening near the east limb. Region 4426 (N12W32, Dso/beta) developed during the period and was numbered, but was inactive. Region 4421 (S12E02, Hsx/alpha) remained stable and inactive. .Forecast... Solar activity is expected to be at low levels, with M-class flares (R1-R2-Moderate) likely, and a chance for X-class (R3/Strong or greater) flares through 27 Apr, primarily driven by the complexity of Regions 4419, 4420, 4423, and 4425. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit reached high levels with a peak of 5,740 pfu at 24/1820 UTC. The greater than 10 MeV proton flux at geosynchronous orbit was slightly elevated, but remained near background levels. .Forecast... The greater than 2 MeV electron flux is expected to be at moderate to high levels through 27 Apr. The greater than 10 MeV proton flux is expected to remain at background levels, though there is a chance for levels to exceed S1 (Minor) solar radiation storm thresholds due to the flare activity of Region 4419 as it rotates toward the western limb, and Region 4420 as it approaches central solar meridian. Chances diminish to a slight chance on 26-27 Apr. Solar Wind .24 hr Summary... Solar wind parameters reflected near-background conditions. Total field strength averaged between 3-9 nT for most of the period, the Bz component varied between +/- 5 nT, and solar wind speeds remained between 350 and 450 km/s. Phi angle was predominantly negative until just after 25/0000 UTC when it shifted into a positive orientation. .Forecast... Mild enhancements are possible in the solar wind environment on 25 Apr due to the likely onset of a +CH HSS. Further enhancements are anticipated on 25-26 Apr with the arrival of the glancing influence from the 23 Apr CME. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... The geomagnetic field is expected to be mostly quiet to unsettled for most of 25 Apr, with isolated active periods possible, as the +CH HSS moves into a geoeffective position. Isolated G1-G2 (Minor-Moderate) geomagnetic storming conditions are possible late on 25 Apr into early 26 Apr in response to the arrival of the glancing CMEs. Quiet to unsettled conditions are then anticipated on 27 Apr as CME and +CH HSS influences subside. Space Weather Scales |
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| Three Day Forecast | |
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Issued: 2026 Apr 25 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 3 (below NOAA Scale levels). The greatest expected 3 hr Kp for Apr 25-Apr 27 2026 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Apr 25-Apr 27 2026 Apr 25 Apr 26 Apr 27 00-03UT 3.33 4.67 (G1) 2.67 03-06UT 1.33 4.33 2.67 06-09UT 1.33 3.67 2.33 09-12UT 0.67 3.00 2.33 12-15UT 2.00 3.00 2.33 15-18UT 2.67 2.33 2.33 18-21UT 4.33 2.67 2.33 21-00UT 4.67 (G1) 3.00 2.00 Rationale: Isolated G1-G2 (Minor-Moderate) geomagnetic storming conditions are possible (G1 likely with a chance for G2) late on 25 Apr into early 26 Apr in response to the arrival of the glancing CMEs. 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 Apr 25-Apr 27 2026 Apr 25 Apr 26 Apr 27 S1 or greater 25% 20% 10% Rationale: There is a chance for levels to exceed S1 (Minor) solar radiation storm thresholds due to the flare activity of Region 4419 as it rotates toward the western limb, and Region 4420 as it approaches central solar meridian. Chances diminish to a slight chance on 26-27 Apr. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R2 levels were observed over the past 24 hours. The largest was at Apr 24 2026 1815 UTC. Radio Blackout Forecast for Apr 25-Apr 27 2026 Apr 25 Apr 26 Apr 27 R1-R2 65% 60% 55% R3 or greater 35% 25% 20% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a chance for R3 (Strong or greater) events through 27 Apr, primarily driven by the complexity of Regions 4419, 4420, 4423, and 4425. Space Weather Scales |
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| Weekly Highlights and Forecasts | |
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Issued: 2026 Apr 20 0331 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Highlights of Solar and Geomagnetic Activity 13 - 19 April 2026 Solar activity was at very low to low levels during the period. Very low levels occurred on 14, 15 and 19 Apr, while low levels were observed on 13, 16, 17 and 18 April. Region 4419 (N14, L=314, class/area=Eki/360 on 17 Apr) was the most active region of the period, responsible for 5 out of the 7 C-class flares observed during the week, including the largest one: a C4.1/Sf at 17/0442 UTC. The remainder 2 C-class flares of the period were: a C1.1/Sf at 13/1137 UTC from Region 4414 (N15, L=026, class/area=Dro/030 on 08 Apr) and a C1.6 at 18/0704 UTC from Region 4416 (N19, L=047, class/area=Dai/140 on 12 Apr). Coronal activity was observed during the week with some filament eruptions and few CMEs without Earth-directed components. No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels on 13-17 Apr, followed by a day at moderate levels on 18 Apr and returning to high levels on 19 Apr, with a maximum flux of 3,250 pfu observed at 15/1800 UTC. Geomagnetic field activity was quiet to Moderate storm levels during the period. From 13 to 17 Apr, the geomagnetic activity remained at quiet levels. On 18 Apr, the arrival of a negative polarity CH HSS influence disturbed the Geospace, elevating the activity from unsettled to Moderate storm levels. On 19 Apr, Moderate storm levels were observed during an isolated synoptic period (0600-0900 UTC) and the geomagnetic activity returned to quiet level by the end of the day as the CH HSS effects waned. Forecast of Solar and Geomagnetic Activity 20 April - 16 May 2026 Solar activity is expected to be at low levels, with a varying chance for M-class (R1-R2/Minor-Moderate) flares and a slight chance for X-class (R3/Strong or greater) flares through 16 May. No proton events are expected at geosynchronous orbit, barring any significant, non-recurrent solar activity. The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 20-22 Apr, 27-28 Apr, 30 Apr-05 May and 08-14 May. Normal to moderate electron flux levels are expected on 23-26 Apr, 29 Apr, 06-07 May and 15-16 May. Geomagnetic field activity is expected to remain at quiet to active levels during most of the outlook period, with the exception of 5 days when G1 (Minor) storm levels are anticipated due to the recurrent influence of CH HSS: 29-30 Apr (-CH HSS), 07 May (+CH HSS) and 15-16 May (-CH HSS). 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. |
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