:Product: NOAA 3-day Geomagnetic Forecasts :Issued: 2026 Jun 10 2200 UTC # Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center # NOAA Ap Index Forecast Observed Ap 09 Jun 011 Estimated Ap 10 Jun 008 Predicted Ap 11 Jun-13 Jun 012-015-012 NOAA Geomagnetic Activity Probabilities 11 Jun-13 Jun Active 35/45/40 Minor storm 10/15/10 Moderate storm 01/01/01 Strong-Extreme storm 01/01/01 NOAA Kp index forecast 11 Jun - 13 Jun Jun 11 Jun 12 Jun 13 00-03UT 2.00 3.67 3.00 03-06UT 2.00 4.00 2.00 06-09UT 3.00 4.00 2.00 09-12UT 2.67 2.33 2.67 12-15UT 3.00 2.00 2.67 15-18UT 3.00 2.67 2.67 18-21UT 3.00 2.00 2.67 21-00UT 2.67 2.33 3.00

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 161 Issued at 2200Z on 10 Jun 2026 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (11 Jun, 12 Jun, 13 Jun). IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 482 km/s at 09/2102Z. Total IMF reached 8 nT at 10/1802Z. The maximum southward component of Bz reached -5 nT at 10/1036Z. Electrons greater than 2 MeV at geosynchronous orbit remained below threshold of 1,000 pfu during the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (11 Jun, 13 Jun) and quiet to active levels on day two (12 Jun). III. Event probabilities 11 Jun-13 Jun Class M 40/40/40 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 10 Jun 124 Predicted 11 Jun-13 Jun 130/128/128 90 Day Mean 10 Jun 125 V. Geomagnetic A Indices Observed Afr/Ap 09 Jun 010/011 Estimated Afr/Ap 10 Jun 007/008 Predicted Afr/Ap 11 Jun-13 Jun 010/012-013/015-010/012 VI. Geomagnetic Activity Probabilities 11 Jun-13 Jun A. Middle Latitudes Active 30/35/30 Minor Storm 05/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/30/35 Major-severe storm 35/45/35

Product: 3-Day Forecast Issued: 2026 Jun 10 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 Jun 10-Jun 12 2026 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Jun 10-Jun 12 2026 Jun 10 Jun 11 Jun 12 00-03UT 2.00 2.00 3.67 03-06UT 1.33 2.00 4.00 06-09UT 1.33 3.00 4.00 09-12UT 2.67 2.67 2.33 12-15UT 2.00 3.00 2.00 15-18UT 2.00 3.00 2.67 18-21UT 2.00 3.00 2.00 21-00UT 2.67 2.67 2.33 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 Jun 10-Jun 12 2026 Jun 10 Jun 11 Jun 12 S1 or greater 10% 10% 10% Rationale: A slight chance of solar radiation storms are expected through 12 Jun. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Jun 10-Jun 12 2026 Jun 10 Jun 11 Jun 12 R1-R2 55% 55% 55% R3 or greater 15% 15% 15% Rationale: Solar activity is likely to be moderate (R1-R2, Minor-Moderate) with a slight chance for an X-class flares (R3-Strong) through 12 Jun, mainly due to the flare potential of Regions 4464 and 4465.

Product: Forecast Discussion Issued: 2026 Jun 10 1230 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center Solar Activity .24 hr Summary... Solar activity remained at low levels with most of the C-level activity originating from Region 4465 (N09E47, Dsi/beta-gamma), including the largest flare of the day; a C2.6 observed at 10/0059 UTC. There are currently 8 numbered sunspot regions on the disk, with the inclusion of newly numbered Regions 4466 (N06W24, Dao/beta) and 4467 (S08W02, Bxo/beta. A Type-II radio sweep was observed by two RSTN stations at 09/1557 UTC, with estimated velocity of 917 km/s, likely associated with C-class flaring from Region 4463 (N16E03, Hsx/alpha). The plage Region 4461 (S21, L=012) also produced some of the C-flares of the period, including a C2.3/1f (113 mil) at 09/1918 UTC. Some CME activity was observed in the coronagraph imagery during the period. One CME first observed at the NE quadrant of LASCO/C2 around 09/1630 UTC which was associated with an eruption near (and south of) Region 4463. Preliminary analysis suggest glancing effects near-Earth on 14 June. .Forecast... Solar activity is likely to be moderate with a slight chance for an X-class flares through 12 Jun, mainly due to the flare potential of Regions 4464 (S12E04, Dsi/beta) and 4465. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit reached high levels with a peak flux of 4,259 pfu at 09/1525 UTC. The greater than 10 MeV proton flux remained at background levels during the period. .Forecast... The greater than 2 MeV electron flux levels at geosynchronous orbit are likely to decay to low to moderate levels on 10-12 Jun. The greater than 10 MeV proton flux is expected to remain at background levels. Solar Wind .24 hr Summary... Solar wind speed remained slightly elevated after the passage of a weak transient starting near 09/0950 UTC. The total IMF saw an increase of the IMF from 5nT to 10 nT and the Bz component turned predominately south until about 09/1500 UTC. Another period of southward Bz component occurred between 09/1635-2000 UTC, reaching -8 nT at 09/1810 UTC. The transient also resulted in an increased density and temperature. Solar wind speed oscillating around 450 km/s during the enhanced period, but speeds decayed to near 400 km/s by the end of the period. The Phi angle remained mostly in the positive sector through about 09/2256 UTC when it shifted northward. .Forecast... Background solar wind conditions are expected through midday 11 June when a -CH HSS is anticipated to become geoeffective through 12 June. Geospace .24 hr Summary... The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. .Forecast... The geomagnetic field is expected to be at quiet to unsettled levels on 10 and 11 June, becoming unsettled to active on 12 June.

Product: Forecast Discussion Issued: 2026 Jun 10 0030 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center Solar Activity .24 hr Summary... Solar activity remained at low levels with most of the C-level activity originated from Region 4465 (N09E54, Dsi/beta-gamma), including the largest flare of the day; a C4.5/Sf observed at 09/0423 UTC. There are currently 8 numbered sunspot regions on the disk, with the inclusion of newly numbered Region 4466 (N06W16, Bxo/beta). Departed Region 4455 (N15, L=092) continued to produced some weak C-class flares, including a C3.2 at 09/0700 UTC. A Type-II radio sweep was observed by two RSTN stations at 09/1557 UTC, with estimated velocity of 917 km/s, likely associated with C-class flaring from Region 4463. The plage Region 4461 (S21W23, L=11) also produced some of the C-flares of the period, including a C2.3/1F (113 mil) at 09/1918 UTC. Some CME activity was observed in the coronagraph imagery during the period. One CME first observed at the NE quadrant of LASCO/C2 around 09/1630 UTC which was associated with an eruption near (and south of) Region 4463 (N16E10, Hsx/alpha). Preliminary analysis suggest glancing effects near-Earth on 14 June. .Forecast... Solar activity is likely to be moderate with a slight chance for an X-class flares through 12 Jun, mainly due to the flare potential of Regions 4464 (S12E11, Ehi/beta) and 4465. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit reached high levels with a peak flux of 4,259 pfu at 09/1525 UTC. The greater than 10 MeV proton flux remained at background levels during the period. .Forecast... The greater than 2 MeV electron flux levels at geosynchronous orbit are likely to continue reaching high levels through 10 June, returning to moderate levels on 11-12 June. The greater than 10 MeV proton flux has a slight chance of crossing threshold through 12 Jun. Solar Wind .24 hr Summary... Solar wind speed suggested the passage of a weak transient starting near 09/0950 UTC, with an increase of the total IMF from 5nT to 10 nT and the Bz component turning predominately south until about 09/1500 UTC. Another period of southward Bz component occurred between 09/1635-2000 UTC, reaching -8 nT at 09/1810 UTC. The transient also resulted in an increased density and temperature. Solar wind speed remained oscillating around 450 km/s during the period. The Phi angle remained mostly in the positive sector during the day. .Forecast... Background solar wind conditions are expected to be restored by 11 June, and a -CH HSS is anticipated to become geoeffective on 12 June, disturbing the near-Earth solar wind parameters. Geospace .24 hr Summary... The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. .Forecast... The geomagnetic field is expected to be at quiet to active levels on 10 and 12 June, with a day of quiet to unsettled levels in between (11 Jun).

Product: 3-Day Forecast Issued: 2026 Jun 10 0030 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 Jun 10-Jun 12 2026 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Jun 10-Jun 12 2026 Jun 10 Jun 11 Jun 12 00-03UT 3.67 2.00 3.67 03-06UT 2.67 2.00 4.00 06-09UT 2.67 3.00 4.00 09-12UT 2.00 2.67 2.33 12-15UT 2.67 3.00 2.00 15-18UT 2.00 3.00 2.67 18-21UT 2.67 3.00 2.00 21-00UT 3.00 2.67 2.33 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 Jun 10-Jun 12 2026 Jun 10 Jun 11 Jun 12 S1 or greater 10% 10% 10% Rationale: A slight chance of solar radiation storms are expected through 12 Jun. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Jun 10-Jun 12 2026 Jun 10 Jun 11 Jun 12 R1-R2 55% 55% 55% R3 or greater 15% 15% 15% Rationale: Solar activity is likely to be moderate (R1-R2, Minor-Moderate) with a slight chance for an X-class flares (R3-Strong) through 12 Jun, mainly due to the flare potential of Regions 4464 (S12E11, Ehi/beta) and 4465.

:Product: NOAA 3-day Geomagnetic Forecasts :Issued: 2026 Jun 09 2200 UTC # Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center # NOAA Ap Index Forecast Observed Ap 08 Jun 008 Estimated Ap 09 Jun 012 Predicted Ap 10 Jun-12 Jun 012-012-015 NOAA Geomagnetic Activity Probabilities 10 Jun-12 Jun Active 45/35/45 Minor storm 15/10/15 Moderate storm 01/01/01 Strong-Extreme storm 01/01/01 NOAA Kp index forecast 10 Jun - 12 Jun Jun 10 Jun 11 Jun 12 00-03UT 3.67 2.00 3.67 03-06UT 2.67 2.00 4.00 06-09UT 2.67 3.00 4.00 09-12UT 2.00 2.67 2.33 12-15UT 2.67 3.00 2.00 15-18UT 2.00 3.00 2.67 18-21UT 2.67 3.00 2.00 21-00UT 3.00 2.67 2.33