Daily Report

(last updated 14 Sep 2026 23:30 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/14 SEPTEMBER 2026 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 14 SEPTEMBER AND FORECAST FOR 15 SEPTEMBER - 17 SEPTEMBER STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 14 Sep: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 14 Sep: 104/53 1B. SOLAR FORECAST 15 Sep 16 Sep 17 Sep Activity R0 R0 R0 Fadeouts None expected None expected None expected 10.7cm/SSN 105/54 100/48 95/41 COMMENT: Solar flare activity on UT day 14-Sep was at the R0 level, with no notable solar flares. There are currently four numbered sunspot regions visible on the solar disk. Active region (AR) 4527 (N03W61, alpha) showed development in it's main spot but is otherwise small and magnetically simple. All other sunspot regions are small, simple and stable or in decay. Solar flare activity is expected to be at the R0 level over 15-17 Sep. The >10 MeV proton flux as measured at GOES was elevated on 14-Sep, but below the S1 threshold. S0 conditions with a chance of S1 are expected over 15-16 Sep due to elevated proton flux. S0 conditions are expected on 17-Sep. A west directed, narrow CME is visible in SOHO and STEREO-A imagery from 1124UT, associated with an eruption on disk at around S18W29 from 1036UT, visible in GOES SUVI, SDO and H-Alpha imagery. This CME is expected to combine with a CME first observed on 13-Sep to produce a glancing impact on 1900UT on 16-Sep. The solar wind speed initially declined and then increased slightly over the UT day. The wind speed mostly ranged between 315 km/s and 470 km/s and is currently at around 400 km/s. The IMF became enhanced in the second half of the UT day. Possibly due to the arrival of a CME first observed on 09-Sep. The peak total field strength (Bt) was 14 nT the north-south IMF component range (Bz) was +12 to -7 nT. A pair of coronal holes in the southern and northern hemispheres are expected to increase the solar wind speed over 15-17 Sep. An additional increase is expected on 16-Sep due to the arrival of a glancing CME impact late on this day. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 14 Sep: G0 Estimated Indices 14 Sep : A K Australian Region 9 22222323 Cocos Island - -------- Darwin 10 32222323 Townsville 11 23222333 Learmonth 10 22222333 Alice Springs - -------- Gingin - -------- Canberra - -------- Kennaook Cape Grim 7 22122322 Hobart 7 22122322 Estimated Antarctic Regional K Indices 14 Sep : Casey - -------- Mawson - -------- Observed Regional daily pc3 Indices 14 Sep : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth NA Alice Springs NA Gingin NA Canberra NA Hobart 5 (Quiet) 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 14 Sep : A Fredericksburg 11 Planetary 13 Observed AFr/Ap Indices 13 Sep : A K Fredericksburg 4 Planetary 6 2321 1101 2B. MAGNETIC FORECAST Date Ap Conditions 15 Sep 20 G1 16 Sep 28 G1, chance of G2 17 Sep 16 G0-G1 COMMENT: ASWFC Geomagnetic Warning 55 was issued on 13 September and is current for 13-15 Sep. G0 geomagnetic conditions were observed at the planetary level and in the Australian region on UT day 14-Sep. Conditions in the Antarctic region are unknown due to a data outage. G1 geomagnetic conditions are expected on 15-Sep due to the anticipated arrival of two coronal hole high speed wind streams. G1 conditions, with a chance of G2 are expected on 16-Sep due to ongoing coronal hole high speed wind stream effects, combined with a glancing CME impact late in the day. G0-G1 conditions are expected on 17-Sep due to ongoing effects. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 14 Sep Normal-fair Normal-fair Normal-fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 15 Sep Normal Normal-fair Fair 16 Sep Fair Fair Fair-poor 17 Sep Normal Normal-fair Fair COMMENT: HF radio propagation conditions on UT day 14-Sep were mostly normal, with degraded conditions observed in the northern hemisphere in the first half of the UT day. HF radio propagation conditions may become degraded over 15-17 Sep due to anticipated geomagnetic activity over the period, with the strongest degradations expected on 16-17 Sep and at high latitudes. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 14 Sep 66 Observed Australian Regional MUFs Cocos Island Region: No data available during local day. No data available during local night. Niue Island Region: Near predicted monthly values. Northern Australian Region: Near predicted monthly values. Southern Australian Region: Near predicted monthly values. Antarctic Region (Casey/Davis/Mawson): Enhanced by 15% over the UT day. Monthly T index: Month T index Aug 66 Sep 62 Oct 60 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 15 Sep 60 Near predicted monthly values/depressed 5 to 10% 16 Sep 45 Near predicted monthly values/depressed 5 to 15% 17 Sep 55 Near predicted monthly values/depressed 5 to 15% COMMENT: Maximum usable frequencies (MUFs) in the Australian region on UT day 14-Sep were near predicted monthly values. MUFs are expected to be near predicted monthly values to depressed by up to 10% on 15-Sep and near predicted monthly values to depressed by up to 15% over 16-17 Sep. These depressions are due to anticipated geomagnetic activity and are more likely in the southern Australian region. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 13 Sep Daily Proton Fluence >1 MeV: 7.7E+04 Daily Proton Fluence >10 MeV: 2.0E+04 Daily Electron Fluence >2 MeV: 9.10E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability:10% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: B2.9 Solar Wind Day Averaged Data for 13 Sep Speed: 387 km/sec Density: 1.5 p/cc Temp: 170000 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------