#swpc

Space Weather Message Code: ALTK06 Serial Number: 682 Issue Time: 2026 Jan 19 1924 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2026 Jan 19 1923 UTC Synoptic Period: 1800-2100 UTC Active Warning: Yes NOAA Scale: G2 - Moderate NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation 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.

Product: Forecast Discussion Issued: 2025 Nov 10 1230 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center Solar Activity .24 hr Summary... Solar activity reached high levels again this period, with another X-class flare. Region 4274 (N25W17, Ekc/beta-gamma-delta) produced a long-duration X1.2/2B flare (R3-Strong) at 10/0919 UTC, with associated Type-II (1321 km/s) and Type-IV radio sweeps, and an F10.7 cm radio burst (860 sfu). This event also had a Castelli-U radio burst, which is a good indication a proton event is possible, as well as a halo CME. The bulk of the full halo CME, first observed in LASCO C2 imagery at 10/0936 UTC, appears to have a NW bias, but with the source location being near center disk, an Earth-directed component is highly likely. Analysis is underway to determine arrival time at Earth. Region 4274 showed little change and maintained its delta configuration. Regions 4276 (S18E20, Dao/beta-gamma) exhibited slight growth in its intermediate spots, while Region 4277 (S07E20, Dsi/beta) lost some of its trailing spots. Both of these spot groups were fairly inactive, producing only few C-class flares each. The remainder of the spot groups were relatively unchanged and inactive. .Forecast... M-class flares (R1/R2-Minor/Moderate) are likely, with a chance for an isolated X-class flare (R3-Strong), on 10-12 Nov. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels. The greater than 10 MeV proton flux reached S1 (Minor) storm levels, and was still rising at the time of this writing. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels on 10-12 Nov. The greater than 10 MeV proton flux to is expected to continue at S1 (Minor) storm levels on 10-11 Nov following the X1.2 flare from Region 4274. There is a chance for S1 (Minor) storm levels on 12 Nov due to the flare potential and location of Region 4274. Solar Wind .24 hr Summary... Solar wind parameters continued to reflect persistent negative polarity CH HSS influences. Total field strength observed several readings near 8 nT, but averaged near 5 nT. The Bz component was mostly north, but did see a brief period sustained southward near -6 nT. Solar wind speeds were between 450 km/s to 600 km/s. Phi was variable through the first half of the period before turning mostly negative for the second half. .Forecast... The solar wind environment is likely to become mildly enhanced with CME influences on 10 Nov as the 07 Nov CME passes in close proximity to Earth. Stronger solar wind disturbances are likely over 11-12 Nov due to the anticipated arrival of the 09 Nov asymmetric halo CME. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... Periods of G1 (Minor) geomagnetic storming are likely on 10 Nov due to possible CME enhancements as the 07 Nov CME passes in close proximity to Earth. Periods of G1-G2 (Minor-Moderate) geomagnetic storming are likely on 11-12 Nov in response to the anticipated arrival of the 09 Nov asymmetric halo CME.

Product: 3-Day Forecast Issued: 2025 Jan 05 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 5 (NOAA Scale G1). The greatest expected 3 hr Kp for Jan 05-Jan 07 2025 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Jan 05-Jan 07 2025 Jan 05 Jan 06 Jan 07 00-03UT 3.67 3.00 2.67 03-06UT 2.67 3.67 2.33 06-09UT 3.00 2.67 2.00 09-12UT 3.67 2.33 2.33 12-15UT 3.00 2.00 1.33 15-18UT 3.33 2.33 2.00 18-21UT 3.33 2.67 2.00 21-00UT 4.67 (G1) 2.67 2.33 Rationale: Isolated G1 periods remain likely on 05 Jan as CH HSS effects persist. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was above S-scale storm level thresholds. Solar Radiation Storm Forecast for Jan 05-Jan 07 2025 Jan 05 Jan 06 Jan 07 S1 or greater 99% 25% 10% Rationale: An S1 (Minor) solar radiation storm is expected to continue on 05 Jan. A return to background-like conditions is expected by 06 Jan where a slight chance for an event will remain for 07 Jan. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R3 levels were observed over the past 24 hours. The largest was at Jan 04 2025 1248 UTC. Radio Blackout Forecast for Jan 05-Jan 07 2025 Jan 05 Jan 06 Jan 07 R1-R2 75% 75% 75% R3 or greater 25% 25% 25% Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected, with a chance for isolated R3 (Strong) or greater events through 07 Jan, as AR 3947 continues to mature and a number of active regions approach the western limb.

Space Weather Message Code: WARK06 Serial Number: 560 Issue Time: 2025 Feb 15 1034 UTC WARNING: Geomagnetic K-Index of 6 expected Valid From: 2025 Feb 15 1030 UTC Valid To: 2025 Feb 15 1500 UTC Warning Condition: Onset NOAA Scale: G2 - Moderate NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation 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 Message Code: ALTK08 Serial Number: 50 Issue Time: 2025 Apr 16 2054 UTC ALERT: Geomagnetic K-index of 8, 9- Threshold Reached: 2025 Apr 16 2055 UTC Synoptic Period: 1800-2100 UTC Active Warning: Yes NOAA Scale: G4 - Severe NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 45 degrees Geomagnetic Latitude. Induced Currents - Possible widespread voltage control problems and some protective systems may mistakenly trip out key assets from the power grid. Induced pipeline currents intensify. Spacecraft - Systems may experience surface charging; increased drag on low earth orbit satellites, and tracking and orientation problems may occur. Navigation - Satellite navigation (GPS) degraded or inoperable for hours. Radio - HF (high frequency) radio propagation sporadic or blacked out. Aurora - Aurora may be seen as low as Alabama and northern California.

Product: 3-Day Forecast Issued: 2025 Jan 08 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 Jan 08-Jan 10 2025 is 3.67 (below NOAA Scale levels). NOAA Kp index breakdown Jan 08-Jan 10 2025 Jan 08 Jan 09 Jan 10 00-03UT 3.67 1.33 1.33 03-06UT 2.33 1.33 1.33 06-09UT 1.67 1.67 1.33 09-12UT 0.67 1.33 1.33 12-15UT 1.67 1.33 1.33 15-18UT 1.67 1.33 1.67 18-21UT 2.00 1.67 1.67 21-00UT 2.33 1.67 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 Jan 08-Jan 10 2025 Jan 08 Jan 09 Jan 10 S1 or greater 10% 10% 10% Rationale: A slight chance for S1 (Minor) solar radiation storming will persist through 10 Jan as multiple CME producing regions transit and exit the western limb. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Jan 07 2025 2305 UTC. Radio Blackout Forecast for Jan 08-Jan 10 2025 Jan 08 Jan 09 Jan 10 R1-R2 55% 55% 55% R3 or greater 15% 15% 15% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a slight chance for isolated R3 (Strong) or greater events through 10 Jan. This is based on the magnetic complexity and persistent activity of Region 3947.

Product: Forecast Discussion Issued: 2025 Jan 06 1230 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center Solar Activity .24 hr Summary... Solar activity was at moderate levels with a total of three M-class flares, all from Region 3947 (N11E21, Dkc/beta-gamma-delta). The largest of these events was an M3.1/1n flare at 06/0152 UTC. The other two M-class flares were an M2.4 flare at 05/1537 UTC and an M1.4/1f flare at 06/0350 UTC. Multiple C-class flares observed from this region as well. Region 3947 maintained a weak delta signature in its trailing spots, but observed slight overall decay. Region 3941 (S06W74, Dso/beta) produced a C5.0 flare at 05/1817 UTC, and Region 3949 (S05W53, Cso/beta) added a C4.8/Sf at 05/1807 UTC. Region 3943 (S16W10, Cso/beta) contributed a C4.3 flare at 05/2057 UTC, and Region 3945 rounded out the C-class flares with a C3.2/Sf flare at 06/0751 UTC. The remaining active regions were either relatively stable or in decay. No new Earth-directed CMEs were observed in available coronagraph imagery. However, a fast CME originating from AR 3939 on 04 Jan was modeled and determined to be a glancing blow at Earth by late on 06 Jan with the bulk of the material being well ahead of Earth's orbit. .Forecast... R1-R2 (Minor-Moderate) radio blackouts are expected, with a chance for isolated R3 (Strong) or greater events through 07 Jan, as AR 3947 continues to mature and a number of active regions approach the western limb. Probabilities decrease slightly on 08 Jan as multiple regions transit and exit the western limb, but AR 3947 remains. Energetic Particles .24 hr Summary... The greater than 2 MeV electron flux reached a peak flux of 1,070 pfu at 05/1950 UTC, but was not sustained long enough to warrant a SWPC electron flux alert. The greater than 10 MeV proton flux began the period in S1 (Minor) solar radiation storm levels at 04/2255 UTC, reached a peak flux of 20 pfu at 05/0055 UTC and ended at 06/0940 UTC. .Forecast... The greater than 2 MeV electron flux is expected to briefly reach high levels early on 06 Jan and return to normal to moderate levels for 07-08 Jan. The greater than 10 MeV proton flux is expected to continue a gradual trend towards background-like levels over the course of 06 Jan while a chance for another event remains. A slight chance for S1 (Minor) solar radiation storming will persist on 07 Jan and through 08 Jan as multiple CME producing regions transit and exit the western limb. Solar Wind .24 hr Summary... The solar wind environment reflected sustained, but slightly weakening, positive polarity CH HSS influence. Total field primarily ranged 6-9 nT, the Bz component underwent several, sustained southward deflections of -5 to -7 nT, and solar wind speeds gradually decreased from ~600 km/s to -530 km/s. Phi remained in a positive orientation. .Forecast... An enhanced solar wind environment due to positive polarity CH HSS influence is expected to persist, although gradually weakening, through 08 Jan. An additional shock to the environment is likely by late on 06 Jan due to the aforementioned 04 Jan CME giving glancing effects. Geospace .24 hr Summary... The geomagnetic field was unsettled to active. .Forecast... G1 (Minor) geomagnetic storming is likely, with a chance for an isolated G2 (Moderate) period, by late on 06 Jan due to glancing effects from the periphery of the 04 Jan CME. Unsettled to active conditions are expected on 07 Jan as any CME effects linger, coupled with weakening positive polarity CH HSS effects. Quiet to unsettled conditions are expected on 08 Jan as CH HSS effects taper off.

Product: 3-Day Forecast Issued: 2025 Jan 06 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 Jan 06-Jan 08 2025 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Jan 06-Jan 08 2025 Jan 06 Jan 07 Jan 08 00-03UT 3.33 4.00 2.33 03-06UT 4.00 3.33 2.67 06-09UT 3.00 2.67 2.67 09-12UT 2.67 2.33 1.67 12-15UT 3.33 2.00 1.67 15-18UT 3.33 2.00 1.67 18-21UT 3.33 2.00 2.00 21-00UT 4.67 (G1) 2.67 2.33 Rationale: G1 (Minor) geomagnetic storming is likely, with a chance for an isolated G2 (Moderate) period, by late on 06 Jan due to glancing effects from the periphery of the 04 Jan CME. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was above S-scale storm level thresholds. Solar Radiation Storm Forecast for Jan 06-Jan 08 2025 Jan 06 Jan 07 Jan 08 S1 or greater 15% 15% 15% Rationale: A slight chance for S1 (Minor) solar radiation storming will persist on 07 Jan and through 08 Jan as multiple CME producing regions transit and exit the western limb. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Jan 06 2025 0152 UTC. Radio Blackout Forecast for Jan 06-Jan 08 2025 Jan 06 Jan 07 Jan 08 R1-R2 75% 75% 60% R3 or greater 25% 25% 15% Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected, with a chance for isolated R3 (Strong) or greater events through 07 Jan, as AR 3947 continues to mature and a number of active regions approach the western limb. Probabilities decrease slightly on 08 Jan as multiple regions transit and exit the western limb, but AR 3947 remains.