Daily Report

(last updated 12 Jun 2025 23:30 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/12 JUNE 2025 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 12 JUNE AND FORECAST FOR 13 JUNE - 15 JUNE STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW ** ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 12 Jun: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 12 Jun: 142/96 1B. SOLAR FORECAST 13 Jun 14 Jun 15 Jun Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 140/94 140/94 135/89 COMMENT: On UT day 12-Jun solar activity was R0, with no noteworthy solar flares. There are currently 9 numbered sunspot regions on the solar disk. The main spots of AR4105 (S16W42, beta-gamma) have grown closer together, but the region remains mostly quiet. AR4110 (S05W30, beta), AR4112 (S08E06, beta) and AR4114 (N18E49, beta) have all shown minor spot development. All other regions are either stable or in decay. Solar activity is expected to be R0-R1 over 13-15 Jun. Filament movement can be seen early in the UT day 12-Jun in the solar northeastern quadrant, and an associated CME is visible shortly after, although it may overlap with a previous CME from the northeastern quadrant. This filament appears to stretch over to the farside, likely where the source of the CME is. Therefore, this event is not expected to be Earth-directed, although due to coronagraph imagery unavailability there is uncertainty in this conclusion. Several other CMEs were observed on UT day 12-Jun but none were considered geoeffective. S0 solar radiation storm conditions were observed on UT day 12-Jun. S0 solar radiation storm conditions are expected over 13-15 Jun. The solar wind environment on UT day 12-Jun was mildly disturbed, possibly due to ongoing coronal hole effects or weak transient CME influences. The solar wind speed ranged from 493 to 382 km/s. The peak total interplanetary field strength (IMF, Bt) was 16 nT and the north-south IMF component range was +8 to -13 nT. Bz was oriented southward for a prolonged period for several periods of the day. The solar wind environment is expected to remain mildly disturbed but on a declining trend on 13-Jun. A coronal hole may connect with Earth either late 14-Jun or early 15-Jun, possibly associated with a co-rotating interaction region to further disturb the solar wind. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 12 Jun: G1 Estimated Indices 12 Jun : A K Australian Region 20 23354243 Cocos Island 9 23232132 Darwin 20 23344344 Townsville 17 23344243 Learmonth 23 33355243 Alice Springs 21 23354244 Gingin 23 33345344 Canberra 19 22354243 Kennaook Cape Grim 30 32465344 Hobart 29 33464344 Estimated Antarctic Regional K Indices 12 Jun : Macquarie Island 45 34576343 Casey 14 33233143 Mawson 55 66653356 Observed Regional daily pc3 Indices 12 Jun : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 2 (Quiet) Canberra 5 (Quiet) Hobart 25 (Quiet to unsettled) Pc3 pulsations are high frequency (10-45 second period) variations of the Earths magnetic field. Daily pc3-indices are the daily sum of 20 minute pc3-indices for that station and have been shown to be well correlated with rejection of high resolution aeromagnetic survey flight-line data. NOTE: Indices may have been generated from data obtained in cooperation with the following organisations: Geoscience Australia, University of Newcastle Space Physics Group, Australian Government Antarctic Division and International Center for Space Weather Science and Education, Japan. Estimated AFr/Ap Indices 12 Jun : A Fredericksburg 19 Planetary 24 Observed AFr/Ap Indices 11 Jun : A K Fredericksburg 13 Planetary 18 3322 2445 2B. MAGNETIC FORECAST Date Ap Conditions 13 Jun 8 G0, chance G1-G2 14 Jun 14 G0-G1 15 Jun 18 G0-G1 COMMENT: ASWFC Geomagnetic Warning 43 was issued on 11 June and is current for 13-15 Jun. G1 geomagnetic conditions were observed in the Australian region on UT day 12-Jun. G0-G3 geomagnetic conditions were observed in the Antarctic region. The cause of the geomagnetic disturbance was the onset of a coronal hole, and possibly a weak transient CME influence, along with several periods of southward solar wind parameter Bz. Conditions are expected to be similar, with a chance of G2, on 13 Jun, then further periods of G1 are possible on either late 14-Jun or else 15-Jun due to connection to a new coronal hole. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 12 Jun Normal-fair Normal-fair Fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 13 Jun Normal-fair Normal-fair Normal-fair 14 Jun Normal-fair Normal-fair Fair 15 Jun Normal-fair Normal-fair Fair-poor COMMENT: HF radio communication on UT day 12-Jun was normal to mildly degraded. Strongest degradations appeared to be in the northern hemisphere high latitudes. HF radio propagation conditions are expected to be normal to degraded over 13-15 Jun, with the strongest degradations likely by the end of the period due to coronal hole activity. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 12 Jun 108 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 20% during local day. Depressed by 35% during local night. Depressed by 30% after local dawn. Niue Island Region: Mostly near predicted monthly values. Northern Australian Region: Near predicted monthly values during local day. Depressed by 15% during local night. Southern Australian Region: Mostly near predicted monthly values. Antarctic Region (Casey/Davis/Mawson): Depressed by 30% over the UT day. Monthly T index: Month T index May 94 Jun 109 Jul 107 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 13 Jun 90 Depressed 10 to 15%/near predicted monthly values 14 Jun 90 Depressed 10 to 15%/near predicted monthly values 15 Jun 80 Depressed 10 to 20%/near predicted monthly values COMMENT: Maximum usable frequencies (MUFs) in the Australian region on UT day 12-Jun were near predicted values to 15% depressed. Most sites in the Australian region were degraded during local midnight to dawn hours. Spread-F was observed in Hobart and Brisbane; sporadic-E was observed in Darwin and Canberra. MUFs are expected to be near predicted values to 15% depressed over 13-14 Jun, then further depressions are likely as Earth is expected to connect to a coronal hole by this time. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 11 Jun Daily Proton Fluence >1 MeV: 3.8E+05 Daily Proton Fluence >10 MeV: 1.6E+04 Daily Electron Fluence >2 MeV: 2.10E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 4% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: C1.1 DSCOVR Satellite Solar Wind Day Averaged Data for 11 Jun Speed: 443 km/sec Density: 5.4 p/cc Temp: 95900 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------