[Ips-dsgr] ASWFC Daily Report - 19 May 26 issued 2330 UT on 19 May 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed May 20 09:30:49 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 MAY AND FORECAST FOR 20 MAY - 22 MAY
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 May: 106/55
1B. SOLAR FORECAST
20 May 21 May 22 May
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts None expected None expected None expected
10.7cm/SSN 110/60 110/60 108/58
COMMENT: Solar flare activity on UT day 19-May was at the R0
level, with no significant flaring activity. There are currently
five numbered sunspot regions visible on the solar disk. Active
Region (AR) 4441 (N08W13, beta) is the largest region on the
disk and has shown mild decay in its intermediate spots. AR 4436
(N20W63, beta) has exhibited mild growth in its trailer spots.
Region 4443 (S16E36, alpha) has shown mild spot development.
All other sunspot regions are either stable or in decay. Solar
flare activity is expected to be at the R0 level over 20-22 May,
with a chance of R1. S0 solar proton conditions were observed
on UT day 19-May. S0 solar proton conditions are expected over
20-22 May. No Earth-directed coronal mass ejections (CMEs) have
been observed. A northwest-directed CME was observed in LASCO
C2 coronagraph imagery at 19/1101UT. Modelling indicates this
CME is not geoeffective. The solar wind speed on UT day 19-May
initially increased due to a step increase observed at 19/0632UT,
likely indicative of a weak CME arrival. The solar wind speed
decreased over the remainder of the UT day. The solar wind ranged
from 495 to 625 km/s and is currently near 500 km/s. The peak
total interplanetary magnetic field strength (IMF, Bt) was 8
nT and the north-south IMF component (Bz) range was -7 to +5
nT. The solar wind speed is expected to decrease over 20-22 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 May: G0
Estimated Indices 19 May : A K
Australian Region 16 12443432
Cocos Island 9 12233321
Darwin 12 22333332
Townsville 15 23443322
Learmonth 15 22433432
Alice Springs 13 12343421
Gingin 18 22444432
Canberra 14 12443421
Kennaook Cape Grim 17 12444431
Hobart 19 1244443-
Estimated Antarctic Regional K Indices 19 May :
Macquarie Island 44 22666631
Casey 16 33343422
Mawson 37 35544644
Observed Regional daily pc3 Indices 19 May :
Darwin 2 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 34 (Quiet to unsettled)
Canberra 36 (Quiet to unsettled)
Hobart 45 (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 19 May : A
Fredericksburg 14
Planetary 19
Observed AFr/Ap Indices 18 May : A K
Fredericksburg 8
Planetary 9 2222 3223
2B. MAGNETIC FORECAST
Date Ap Conditions
20 May 10 G0
21 May 6 G0
22 May 6 G0
COMMENT: G0 geomagnetic conditions were observed in the planetary
and Australian regions on UT day 19-May. G2 geomagnetic conditions
were observed in the Antarctic region. G0 planetary geomagnetic
conditions are expected over 20-22 May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 May Normal Fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 May Normal Normal Normal-fair
21 May Normal Normal Normal
22 May Normal Normal Normal
COMMENT: Global ionospheric conditions were normal to fair over
UT day 19-May, with most degradations observed in southern hemisphere
regions. Mostly normal HF propagation conditions are expected
over 20-22 May.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 May 50
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Depressed by 25% during local day.
Depressed by 25% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 20% during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Apr 74
May 71
Jun 68
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 May 55 Near predicted monthly values
21 May 65 Near predicted monthly values
22 May 65 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) on UT day 19-May were
near predicted monthly values in the northern Australian region.
MUFs were depressed by 15-20% in southern Australia over the
UT day. Spread-F was observed at Hobart, Perth and Canberra during
local night hours. MUFs are expected to be near predicted monthly
values over 20-22 May.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 May
Daily Proton Fluence >1 MeV: 3.5E+06
Daily Proton Fluence >10 MeV: 2.0E+04
Daily Electron Fluence >2 MeV: 3.00E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:19%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B3.5
DSCOVR Satellite Solar Wind Day Averaged Data for 18 May
Speed: 532 km/sec Density: 1.8 p/cc Temp: 109000 K Bz: 0 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
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Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
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