Daily Report

(last updated 11 Jul 2025 23:32 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/11 JULY 2025 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 11 JULY AND FORECAST FOR 12 JULY - 14 JULY STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW ** ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 11 Jul: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Jul: 132/86 1B. SOLAR FORECAST 12 Jul 13 Jul 14 Jul Activity R1 R1 R1 Fadeouts Possible Possible Possible 10.7cm/SSN 135/89 135/89 135/89 COMMENT: Solar activity on UT day 11-Jul was R0, with no significant flare activity observed. Solar regions AR4138 (N29W10, beta), AR4139 (N22E26, beta), AR4140 (S14E77, beta) produced C class flare activity with the largest flare a C8.0 at 11/1709UT from region AR4138. Solar region AR4136 (N19E43, beta-gamma-delta) whilst being the largest and most magnetically complex region produced little X-ray flare activity and may now be in initial decay, with growth in penumbral area in its trailer spots and decay in its small intermediate spots. Smaller solar region AR4139 showed rapid growth over the past 24 hours. All other sunspot regions are either stable or in decay. There are currently six numbered solar regions on the visible solar disk. A 20 degree long solar filament located at N25W05 visible in GONG H-alpha imagery slowly disappeared during the interval 10/1800-11/0400UT, with minor motion visible in SDO 193 imagery. Solar activity is expected to be R1 over 12-14 Jul. No Earth directed CMEs were observed on UT day 11-Jul. No CME appeared to be associated with the very slow on disk filament lift off. A southeast CME was observed from 11/0924UT associated with southeast limb plasma eruptions and is not considered to be Earth directed. In STEREO-A a sequence of south southwest CMEs were observed over the past 24 hours that could not be correlated to on disk activity. S0 solar radiation storm conditions were observed on UT day 11-Jul. S0 solar radiation storm conditions are expected over 12-14 Jul. A large coronal hole is in the southern solar hemisphere with a narrow transequatorial northward extension of this hole now west of the solar central meridian. The solar wind speed increased on 11-Jul due to a possible combination of a very weak CME arrival from a recent north directed filament eruption and the Earth's entry into a coronal hole wind stream, with an abrupt increase in wind speed observed at 11/0440UT. The solar wind speed ranged from 475 to 340 km/s, and is currently at 445 km/sec. The total interplanetary field strength (IMF, Bt) was 13 nT and the north-south IMF component range (Bz) was +11 to -11 nT. The IMF Bz component was mildly southward 11/0500-1000UT. The solar wind is expected to remain moderately enhanced today due to the ongoing influence of the coronal hole wind stream. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 11 Jul: G0 Estimated Indices 11 Jul : A K Australian Region 10 22233232 Cocos Island 8 23232122 Darwin 11 22233233 Townsville 9 22233222 Learmonth 12 22333233 Alice Springs 10 22233232 Gingin 13 22343133 Canberra 8 12233222 Kennaook Cape Grim 10 11243232 Hobart 10 11243232 Estimated Antarctic Regional K Indices 11 Jul : Macquarie Island 15 01354232 Casey 10 13332132 Mawson 19 04443334 Observed Regional daily pc3 Indices 11 Jul : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 2 (Quiet) Canberra 7 (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 11 Jul : A Fredericksburg 15 Planetary 18 Observed AFr/Ap Indices 10 Jul : A K Fredericksburg 6 Planetary 6 1111 1111 2B. MAGNETIC FORECAST Date Ap Conditions 12 Jul 16 G0-G1 13 Jul 19 G1. chance G2 14 Jul 16 G0-G1 COMMENT: ASWFC Geomagnetic Warning 53 was issued on 11 July and is current for 11-12 Jul. Observations: G0 geomagnetic conditions were observed in the Australian region on UT day 11-Jul. G0-G1 conditions were observed in the Antarctic region. Forecast: G1 periods are possible over 12-14 Jul due to the influence of a coronal hole wind stream. There is a chance for a very weak CME arrival on 13-Jul. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 11 Jul Normal Fair-normal Fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 12 Jul Normal Fair-normal Fair 13 Jul Normal Fair-normal Fair 14 Jul Normal Normal Fair-normal COMMENT: HF radio propagation conditions on UT day 11-Jul were fair to normal. HF radio propagation conditions are expected to be fair at middle to high latitudes over 12-13 Jul, due to an anticipated mild increase in geomagnetic activity from a coronal hole wind stream. HF conditions in the polar regions may be poor at times. Isolated minor shortwave fadeouts are possible. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 11 Jul 76 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 20% during local day. Depressed by 20% during local night. Depressed by 25% after local dawn. Niue Island Region: Depressed by 15% during local day. Depressed by 35% during local night. Northern Australian Region: Depressed by 20% during local day. Depressed by 20% during local night. Depressed by 25% after local dawn. Southern Australian Region: Depressed 15% to near predicted monthly values. Antarctic Region (Casey/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Jun 79 Jul 104 Aug 102 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 12 Jul 75 Depressed 15 to 20%/near predicted monthly values 13 Jul 75 Depressed 15 to 20%/near predicted monthly values 14 Jul 75 Depressed 15 to 20%/near predicted monthly values COMMENT: Maximum usable frequencies (MUFs) in the Australian region on UT day 11-Jul were 25% depressed to near predicted monthly values, with depressed conditions in the the northern Australian region. Spread F was observed during local night hours at Townsville, Learmonth, Perth and Hobart. MUFs are expected to be 15-20% depressed to near predicted monthly values over 12-14 Jul. Degraded HF conditions are expected during local night hours due to mild geomagnetic activity induced by a coronal hole wind stream. Isolated minor shortwave fadeouts are possible. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 10 Jul Daily Proton Fluence >1 MeV: 1.8E+06 Daily Proton Fluence >10 MeV: 1.8E+04 Daily Electron Fluence >2 MeV: 1.30E+08 (moderate fluence) Electron Fluence Daily Deep Dielectric Discharge Probability:12% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: C1.0 DSCOVR Satellite Solar Wind Day Averaged Data for 10 Jul Speed: 382 km/sec Density: 1.4 p/cc Temp: 39100 K Bz: 1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------