| Warnings |
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Space Weather Message Code: ALTK04
Serial
Number: 2442
Issue
Time: 2024 Apr 28 0232 UTC
ALERT: Geomagnetic K-index of 4 Threshold Reached: 2024 Apr 28 0230 UTC Synoptic Period: 0000-0300 UTC Active Warning: Yes 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 |
| Current Condition and Alerts |
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Issued: 2024 Apr 28 1505 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Geophysical Alert Message Solar-terrestrial indices for 27 April follow. Solar flux 153 and estimated planetary A-index 12. The estimated planetary K-index at 1500 UTC on 28 April was 0.67. Space weather for the past 24 hours has been minor. Radio blackouts reaching the R1 level occurred. No space weather storms are predicted for the next 24 hours. Space Weather Scales |
| Forecast Discussion |
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Issued: 2024 Apr 28 1230 UTC
Prepared
by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction
Center
Solar Activity .24 hr Summary... Solar activity reached moderate levels. Region 3654 (S07W29, Ehc/beta-gamma-delta) produced two R1 (Minor) events this period, the largest of which was an M3.0 flare at 27/2140 UTC. Region 3654 exhibited moderate development in the intermediate and trailer spots, and developed a delta magnetic configuration. The remaining regions were either stable or in decay. No Earth-directed CMEs were detected in available imagery. .Forecast... Solar activity is expected to be at low levels over 28-30 Apr with a chance for M-class flare (R1-R2/Minor-Moderate) activity. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels and the greater than 10 MeV proton flux was steady at background levels. .Forecast... The greater than 2 MeV electron flux is expected to be at normal to moderate levels over 28-30 Apr. The greater than 10 MeV proton flux is expected to persist at background levels over 28-30 Apr. Solar Wind .24 hr Summary... The solar wind environment was enhanced early in the period due to positive polarity CH HSS influences. Total field strength reached a peak of 13 nT and the Bz component was varied between +11/-10 nT. Solar wind speeds were steady near 400 km/s. The phi angle was in a mostly positive orientation through the period. .Forecast... Enhanced solar wind conditions are likely over 28-30 Apr due to CH HSS influences and possible transient activity associated with multiple CMEs that are expected to pass in close proximity to Earth over the next few days. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels this period. .Forecast... Geomagnetic field activity is expected to range from quiet to active levels on 28 Apr, and quiet to unsettled levels on 29-30 Apr, due to the anticipated influence of CH HSSs combined with potential transient influence of multiple near-miss CMEs from the past several days. A chance for G1 (Minor) storm periods exists on 28 Apr should these features arrive at Earth and carry periods of significant southward Bz. Space Weather Scales |
| Three Day Forecast |
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Issued: 2024 Apr 28 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 28-Apr 30 2024 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Apr 28-Apr 30 2024 Apr 28 Apr 29 Apr 30 00-03UT 3.67 2.67 2.33 03-06UT 2.00 2.00 2.67 06-09UT 1.33 2.33 2.00 09-12UT 1.33 2.67 2.00 12-15UT 2.67 2.33 1.67 15-18UT 3.00 2.33 1.67 18-21UT 3.67 2.33 2.67 21-00UT 4.00 2.67 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 Apr 28-Apr 30 2024 Apr 28 Apr 29 Apr 30 S1 or greater 5% 5% 5% 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 Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Apr 27 2024 2140 UTC. Radio Blackout Forecast for Apr 28-Apr 30 2024 Apr 28 Apr 29 Apr 30 R1-R2 35% 35% 35% R3 or greater 5% 5% 5% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts over 28-30 Apr. Space Weather Scales |
| Weekly Highlights and Forecasts |
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Issued: 2024 Apr 22 0200 UTC
Prepared
by the US Dept. of Commerce, NOAA, Space Weather Prediction
Center
Highlights of Solar and Geomagnetic Activity 15 - 21 April 2024 Solar activity reached moderate levels on 15 Apr, 16-19 Apr and 21 Apr and was at low levels on 20 Apr. A large amount of numbered regions were recorded on the visible disk, with 26 in total. Region 3639 (N26, L=222, class/area=Eki/320 on 17 Apr) produced the highest flare of the period, an M4.0/1n (R1-Minor) at 15/1932 UTC. 17 other M-class (R1) flares were observed this period from multiple other regions. An complex area of sunspot groups was observed in the southern hemisphere. Region 3638 (S17, L=226, Cai/beta) was far from the most magnetically complex of the group but was very active in its production of eruptions associated with numerous CMEs over the past week. Most of the ejecta was thought to move south of the ecliptic but some of the activity may have produced CMEs whose periphery may be on the Sun-Earth line. Other activity included an eruption N of Region 3636 (S21, L=251, Class/area=Cso/100 on 13 Apr) around 15/0557 UTC. A faint CME thought to be associated with the event was observed in SOHO/LASCO C2 imagery beginning after 15/0648 UTC. Modeling of the CME suggested arrival on 18 Apr but the most pronounced portion of the CME was observed passing Earth over 19 Apr. No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit ranged from normal background to moderate levels. Geomagnetic field activity was ranged from quiet to G3 (Strong) geomagnetic storm levels this period. Quiet to unsettled conditions on 15 Apr increased to G1 (Minor) geomagnetic storm levels due to transient influence from a CME activity on the Sun over 12 Apr. Quiet to unsettled conditions on 17 Apr were associated with a weak passing CME that left the Sun on 14 Apr. Quiet conditions were then observed on 18 Apr as solar wind conditions trended towards nominal levels. An increase to G3 (Strong) geomagnetic storm conditions were observed with the passage of CME associated with activity on the Sun over 15 Apr. Total magnetic field strength (Bt) reached a peak of 18 nT at 19/1425 UTC. The Bz component was sustained in a far southward orientation with a maximum deflection of -17 nT observed at 19/1421 UTC. Solar wind speeds steadily increased from the low 300's to ~500 km/s by the end of 19 Apr. Bt returned to near 5 nT on 20 Apr and the geomagnetic field responded with quiet to unsettled conditions. Active conditions were again observed on 21 Apr following additional periods of sustained Bz south. Forecast of Solar and Geomagnetic Activity 22 April - 18 May 2024 Solar activity is expected to be moderate levels (R1-R2/Minor-Moderate), with a chance for X-class flare R3 (Strong), over 22-27 Apr due to a plethora of productive sunspots rotating towards the W limb. As those spots groups rotate off, solar activity is likely to be a low levels with a chance for M-class (R1-R2), through the remainder of the outlook period due to both developing spots in the E hemisphere and the return of productive spot groups on the farside of the Sun. There is a chance for the greater than 10 MeV proton flux at geosynchronous orbit to reach above the S1 (Minor) levels over 22-27 Apr due to the plethora of sunspots in the W hemisphere. The greater than 2 MeV electron flux at geosynchronous orbit may reach high levels on 22-25 Apr in response to geomagnetic activity observed on 19 Apr. Geomagnetic field activity is like to reach active levels over 22-24 Apr and 26-27 Apr in response to multiple coronal hole high speed streams (CH HSSs). There is potential for combined influence of coronal hole activity and multiple weak transients over 22-24 Apr. Unsettled levels are likely on 25 Apr, 01-03 May, and 05-07 May due to the anticipated return of multiple other weak 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 |
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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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| 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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