Space Weather

Warnings and Alerts

Issue Time: 2026 Mar 17 1836 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: Mar 18: None (Below G1) Mar 19: G2 (Moderate) Mar 20: G1 (Minor) THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT Comment: CME influences are likely on 19 Mar with any effects continuing, but weakening, into 20 Mar. Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms. Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible. Radio - HF (high frequency) radio propagation can fade at higher latitudes. Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state. Space Weather Scales

Current Condition and Alerts

Issued: 2026 Mar 18 1205 UTC Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center Geophysical Alert Message Solar-terrestrial indices for 17 March follow. Solar flux 111 and estimated planetary A-index 4. The estimated planetary K-index at 1200 UTC on 18 March was 1.67. Space weather for the past 24 hours has been minor. Radio blackouts reaching the R1 level occurred. Space weather for the next 24 hours is predicted to be moderate. Geomagnetic storms reaching the G2 level . Space Weather Scales

Forecast Discussion

Issued: 2026 Mar 18 1230 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center Solar Activity .24 hr Summary... Solar activity reached to moderate levels, with an M2.7 at 18/0842 UTC from Region 4392 (S16W13, Cai/beta-gamma). The region had been variable with periods of growth and decay the past two days; however, today it has primarily undergone decay while it retained a mildly mixed magnetic configuration. Region 4391 (N07W61, Bxo/beta) reemerged, but is exhibiting signs of decay. The remaining regions were mainly stable and changed little. New Region 4397 (N19E67, Bxo/beta) came around the E limb and was numbered, though its classification is tentative to due foreshortening effects. The M2.7 was accompanied by a tenflare and Type II radio burst with an estimated velocity of 740-860 km/s. An EUV wave is visible in GOES SUVI, along with faint field line movement in the NW quadrant. The associated CME became visible in STEREO A COR2 at 18/0923 UTC, during a SOHO LASCO data gap. Modeling is currently ongoing. An EUV wave also accompanied a C3.9 flare at 18/0123 UTC, also from Region 4392, visible in various GOES SUVI channels. However, no CME signatures were observed in available imagery, potentially due to data gaps, earthshine interference, and the disk center source location. .Forecast... Solar activity is expected to be low, with a chance for M-class (R1-R2; Minor-Moderate) level events 18-20 Mar due primarily to the minor instability and variability of Region 4392. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels again, with a peak of 2,230 pfu at 17/1715 UTC. The greater than 10 MeV proton flux continued at background levels. .Forecast... The greater than 2 MeV electron flux is likely to reach high levels yet again on 18 Mar. A brief return to normal-moderate levels on 19-20 Mar is expected due to a likely coronal mass ejection (CME) arrival. The greater than 10 MeV proton flux is expected to continue at background values, with a slight chance for an S1 (Minor) level event 19-20 Mar due to possible CME shock enhancement influences. Solar Wind .24 hr Summary... Solar wind parameters were indicative of a gradual return to a slow regime. Total IMF strength was at normal levels of mainly 4-5 nT, and the Bz component was predominantly northward. Solar wind speed decreased from peaks around 500 km/s to around 400 km/s. The phi angle was predominantly positive. .Forecast... The solar wind environment is anticipated to transition to a near normal regime through 18 Mar. An anticipated CME arrival near midday on 19 Mar is expected to enhance solar wind speed and total IMF strength. CME passage is likely to continue into 20 Mar with the additional factors of two other nearby CMEs passing by close to Earth, as well as a possible solar sector boundary crossing (SSBC). All this is likely to lead to a complicated and amplified solar wind regime 19-20 Mar and beyond. Geospace .24 hr Summary... The geomagnetic field was quiet. .Forecast... Quiet to unsettled conditions are expected on 18 Mar as positive polarity CH HSS influences end. The geomagnetic field is likely to become disturbed on 19 Mar, with G2 (Moderate) storm levels likely upon and after the anticipated CME arrival. Active to G1 (Minor) storm conditions are likely on 20 Mar due to continuing but weakening CME passage influences. Space Weather Scales

Three Day Forecast

Issued: 2026 Mar 18 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 2 (below NOAA Scale levels). The greatest expected 3 hr Kp for Mar 18-Mar 20 2026 is 6.33 (NOAA Scale G2). NOAA Kp index breakdown Mar 18-Mar 20 2026 Mar 18 Mar 19 Mar 20 00-03UT 1.00 1.67 5.00 (G1) 03-06UT 1.00 5.33 (G1) 4.33 06-09UT 1.67 6.33 (G2) 3.67 09-12UT 1.33 5.67 (G2) 3.00 12-15UT 1.67 4.33 2.67 15-18UT 2.00 3.33 3.67 18-21UT 2.33 3.67 4.33 21-00UT 2.67 4.00 4.67 (G1) Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are expected over 19-20 Mar due to a CME arrival from 16 Mar with a potential solar sector boundary crossing. 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 Mar 18-Mar 20 2026 Mar 18 Mar 19 Mar 20 S1 or greater 5% 10% 10% Rationale: There is a slight chance for S1 (Minor) or greater solar radiation storms on 19-20 Mar due to the potential for accelerated particles ahead of the CME shock. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Mar 18 2026 0839 UTC. Radio Blackout Forecast for Mar 18-Mar 20 2026 Mar 18 Mar 19 Mar 20 R1-R2 35% 35% 35% R3 or greater 5% 5% 5% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts, with a slight chance for R3 (Strong) events, through 20 Mar, due predominantly to the flaring potential of Region 4392. Space Weather Scales

Weekly Highlights and Forecasts

Issued: 2026 Mar 16 0302 UTC Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center Highlights of Solar and Geomagnetic Activity 09 - 15 March 2026 Solar activity was at low to moderate levels with a total of 37 C-class flares and 2 M-class flares observed. The largest flares of the period were an M1.2 flare on 13/0955 UTC from Region 4384 (N10, L=150, class/area Eho/300 on 03 Mar), a C8.9/1n flare on 13/2023 from Region 4392 (S15, L=017, class/area Cso/170 on 15 Mar), and an M1.0/Sf flare on 15/0939 UTC from Region 4392. The most active region of the period was Region 4381 (N08, L=173, class/area Eao/220 on 03 Mar) which produced a long duration C8.0 flare on 13/1518 UTC in addition to 11 other weak C-class events. No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 09 - 13 Mar and 15 Mar with a peak flux of 2,940 pfu observed at 12/1545 UTC. Normal to moderate levels were observed on 14 Mar. Geomagnetic field activity ranged from quiet to G2 (Moderate) storm levels throughout the 09-15 Mar period. The week began at quiet to unsettled levels on 09 Mar, with active conditions observed on 10-11 Mar due to the influence of a negative polarity coronal hole high speed stream (CH HSS). Conditions returned to mostly quiet to unsettled levels by 12 Mar. Activity intensified midday on 13 Mar, reaching G1 (Minor) to G2 (Moderate) storm levels following the onset of a positive polarity CH HSS. These storming levels continued through the first half of 14 Mar before waning to unsettled and active levels later in the day. On 15 Mar, the field reached active levels early in the period, followed by a return to quiet and unsettled conditions as positive polarity CH HSS effects gradually diminished. Solar wind parameters reflected the influence of two distinct CH HSS regimes during the period. The week began under the influence of a negative polarity CH HSS, with solar wind speeds initially ranging between 450-500 km/s before gradually declining to ambient levels near 400 km/s by 12 Mar. Total magnetic field (Bt) remained mostly around 6 nT during this interval, while the North-South (Bz) component saw periodic southward deflections to -7 nT. A solar sector boundary crossing (SSBC) occurred early on 13 Mar, indicated by a shift in the phi angle from the towards to away sector. This was immediately followed by the onset of a more powerful positive polarity CH HSS. Solar wind speeds rose sharply from 400 km/s to a peak of 725 km/s on 14 Mar. During this period, Bt reached 13 nT and the Bz component reached a maximum southward deflection of -10 nT. By 15 Mar, solar wind speeds began a slow decline but remained elevated near 600 km/s through the end of the period. Forecast of Solar and Geomagnetic Activity 16 March - 11 April 2026 Solar activity is expected to be at low levels, with a slight chance for M-class (R1-R2/Minor-Moderate) flares throughout the outlook period. Elevated probabilities are related to the flare potential of both currently observed spot groups as well as the potential from returning regions. No 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 16-20, 22-30 Mar, 04-09, and 11 Apr due to the influence from multiple, recurrent, CH HSSs. The remainder of the outlook period is likely to be at normal to moderate levels. Geomagnetic field activity levels are likely to reach G1 (Minor) geomagnetic storm levels on 22 Mar, 04 Apr, 09 Apr, and 11 Apr due to CH HSS influences. G2 (Moderate) geomagnetic storm levels are likely on 11 Mar and 10 Apr due to CH HSS influences. Unsettled to active levels are likely on 16-18, 20, 23-27, 30-31 Mar and 03 and 05-07 Apr. All elevated levels of geomagnetic activity are associated with the anticipated influence of multiple, recurrent, CH HSSs. The remainder of the outlook period is likely to be at mostly quiet levels. 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

Channel | Region of atmosphere | Primary ion(s) 171Å | quiet corona, upper transition region | Fe IX

Daily Image AIA 171 PFSS Model

Channel | Region of atmosphere | Primary ion(s) 171Å | quiet corona, upper transition region | Fe IX

Daily Image AIA 193

Channel | Region of atmosphere | Primary ion(s) 193Å | corona and hot flare plasma | Fe XII, XXIV

Daily Image AIA 304

Channel | Region of atmosphere | Primary ion(s) 304Å | chromosphere, transition region | He II

Daily Video AIA 171

Daily Video AIA 171 PFSS Model

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

Daily Video HMI Continuum

Daily Video 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

NO CURRENT DATA Insert LASCO

Log Polar View C2 C3 and AIA 304

NO CURRENT DATA Insert Log Polar

Combined C2 C3 and AIA 304 Video

NO CURRENT DATA Insert LASCO Video

Log Polar View C2 C3 and AIA 304 Video

NO CURRENT DATA Insert Log Polar 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.

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