[Ips-dsgr] ASWFC Daily Report - 19 October 25 issued 2330 UT on 19 Oct 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Oct 20 10:30:49 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 OCTOBER AND FORECAST FOR 20 OCTOBER - 22 OCTOBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 19 Oct: R1
Flares Max Fadeout Freq. Sectors
M1.0 0156UT possible lower West Pacific
M1.8 2015UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Oct: 149/104
1B. SOLAR FORECAST
20 Oct 21 Oct 22 Oct
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 150/105 152/107 150/105
COMMENT: Solar activity on UT day 19-Oct was at the R1 level,
due to an M1.0 flare at 19/0156UT and an M1.8 flare at 19/2015UT.
There are currently eight numbered sunspot regions and one unnumbered
region visible on the solar disk. All the M-class flares of the
UT day were produced by AR4246 (N25W93) which is no longer visible
on the solar disk. AR4257 (S08E53, beta) showed spot development
over the UT day. An unnumbered region has recently rotated onto
the solar disk at around S05W80 with alpha magnetic complexity.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be at R0-R1 levels over 20-22 Oct. S0
solar radiation conditions were observed on UT day 19-Oct. S0
solar radiation conditions are expected over 20-22 Oct. Two east
directed CMEs were observed on 19-Oct, but neither are considered
geoeffective. A disappearing solar filament was observed from
19/1540UT at around N07E50 in H-Alpha, SDO and GOES SUVI imagery.
No associated CME is visible in available coronagraph imagery,
further analysis will be performed when more imagery is available.
The solar wind speed on UT day 19-Oct increased, mostly ranging
between 450 and 600 km/s and is currently near 580 km/s. The
peak total interplanetary magnetic field strength (IMF, Bt) was
13 nT and the north-south IMF component (Bz) range was -10 to
+9 nT. The solar wind speed is expected to remain elevated over
20-21 Oct due to coronal hole high speed wind stream effects
from an equatorial coronal hole. A decline is expected on 22-Oct.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Oct: G0
Estimated Indices 19 Oct : A K
Australian Region 12 33322323
Cocos Island 8 32222321
Darwin 13 33322324
Townsville 13 33322333
Learmonth 12 33322323
Alice Springs 12 33322323
Gingin 12 42312323
Canberra 12 33322323
Kennaook Cape Grim 13 33332323
Hobart 13 33332323
Estimated Antarctic Regional K Indices 19 Oct :
Macquarie Island 20 43254422
Casey 22 45532323
Mawson 29 54343454
Observed Regional daily pc3 Indices 19 Oct :
Darwin 2 (Quiet)
Townsville 0 (Quiet)
Learmonth 6 (Quiet)
Alice Springs 2 (Quiet)
Gingin 76 (Active)
Canberra 92 (Minor storm)
Hobart 100 (Minor storm)
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 19 Oct : A
Fredericksburg 16
Planetary 18
Observed AFr/Ap Indices 18 Oct : A K
Fredericksburg 20
Planetary 36 4454 3564
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Oct 13 G0, chance of G1
21 Oct 8 G0
22 Oct 5 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 19-Oct. G1 conditions were observed at the planetary
level and in the Antarctic region. G0 conditions, with a chance
of G1 are expected on 20-Oct and G0 conditions are expected over
21-22 Oct as high speed wind stream effects ease.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Oct Normal Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Oct Normal Normal Normal-fair
21 Oct Normal Normal Normal-fair
22 Oct Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 19-Oct were
degraded in the first half of the day mostly in the southern
hemisphere with conditions easing towards normal over the rest
of the day. Mostly normal HF conditions are expected over 20-22
Oct. Shortwave fadeouts are possible.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Oct 67
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Enhanced by 15% during local day.
Depressed by 20% during local night.
Northern Australian Region:
Depressed by 20% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Depressed by 30% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Sep 109
Oct 89
Nov 89
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 Oct 87 Near predicted monthly values
21 Oct 90 Near predicted monthly values
22 Oct 90 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 96 was issued on 19
October and is current for 19-20 Oct. Maximum usable frequencies
(MUFs) in the Australian region on UT day 19-Oct were depressed
by 20% in the northern Australian region and 30% in the southern
Australian region during local daylight hours. Conditions recovered
towards monthly predicted values during local night hours. Mild
spread F was observed at Hobart during local night hours. MUFs
are expected to be near predicted monthly values over 20-22 Oct.
Shortwave fadeouts are possible.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Oct
Daily Proton Fluence >1 MeV: 3.5E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 1.60E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C2.3
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Oct
Speed: 463 km/sec Density: 8.0 p/cc Temp: 133000 K Bz: -3 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list