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| Warnings and Alerts | |
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| Current Condition and Alerts | |
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Issued: 2026 Apr 20 1205 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Geophysical Alert Message Solar-terrestrial indices for 19 April follow. Solar flux 105 and estimated planetary A-index 23. The estimated planetary K-index at 1200 UTC on 20 April was 3.67. 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 |
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| Forecast Discussion | |
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Issued: 2026 Apr 20 1230 UTC
Prepared
by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction
Center
Solar Activity .24 hr Summary... Solar activity reached low levels with an isolated C1.0/Sf flare from Region 4419 (N15W19, Eko/beta-gamma). This region exhibited minor growth in overall area, but had slight decay in the number of spots. Aside from the aforementioned C1 flare, Region 4419 contributed mostly B-level enhancements during the period. Region 4415 (S18W80, Hsx/alpha) remained unchanged and was inactive. At approximately 19/1449 UTC, a disappearing solar filament was noted in GONG H-alpha and GOES SUVI imagery near N07E31. Subsequent analysis indicated a trajectory well behind Earths orbit with no impacts expected. No Earth directed CMEs were observed in coronagraph imagery. .Forecast... Solar activity is expected to be at very low levels, with a chance for isolated C-class activity on 20-22 Apr, primarily due to the flare potential from Region 4419 and limb activity. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit reached high levels at 19/1925 UTC with a maximum reading of 1,187 pfu. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to be at moderate to high levels on 20-22 Apr. The greater than 10 MeV proton flux is expected to continue at background levels on 20-22 Apr. Solar Wind .24 hr Summary... Solar wind parameters continued to reflect negative polarity CH HSS influence throughout most of the period. Total field ranged from 2-7 nT, the Bz component fluctuated between +/-5 nT, and solar wind speeds gradually decreased from 550 km/s to 400 km/s. At approximately 20/0600 UTC, a weak enhancement was observed in the solar wind environment. Total field increased slightly to 8 nT, the Bz component simultaneously saw a southward deflection to -8 nT, and wind speeds increased back to near 500 km/s. Phi was mostly in a negative orientation, with isolated oscillations into a positive position. .Forecast... Weakening enhanced solar wind conditions are expected on 20-21 Apr as the CH HSS continues to move from its geoeffective position. A return to mostly nominal conditions is expected by 22 Apr. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels as CH HSS influence persists. .Forecast... Mostly quiet to unsettled levels, with isolated active conditions, are expected on 20-21 Apr as HSS effects diminish. Mostly quiet levels are expected, with possible unsettled periods on 22 Apr as CH HSS influence dissipates. Space Weather Scales |
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| Three Day Forecast | |
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Issued: 2026 Apr 20 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 Apr 20-Apr 22 2026 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Apr 20-Apr 22 2026 Apr 20 Apr 21 Apr 22 00-03UT 0.67 3.33 2.67 03-06UT 2.33 4.00 2.00 06-09UT 4.00 3.00 2.33 09-12UT 3.67 2.67 2.00 12-15UT 3.67 2.33 2.00 15-18UT 3.00 3.00 2.33 18-21UT 3.00 2.67 2.00 21-00UT 2.67 2.33 2.00 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 Apr 20-Apr 22 2026 Apr 20 Apr 21 Apr 22 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 Apr 20-Apr 22 2026 Apr 20 Apr 21 Apr 22 R1-R2 5% 5% 10% 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 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 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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| 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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