[Ips-dsgr] ASWFC Daily Report - 27 May 25 issued 2331 UT on 27 May 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed May 28 09:31:20 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 MAY AND FORECAST FOR 28 MAY - 30 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 27 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 May: 137/91
1B. SOLAR FORECAST
28 May 29 May 30 May
Activity R1-R2 R1-R2 R1-R2
Fadeouts Possible Possible Possible
10.7cm/SSN 133/87 130/84 130/84
COMMENT: Solar activity on UT day 27-May was at the R0 level
with a long duration C5.0 at 27/1012UT. There are currently nine
numbered sunspot regions visible on the solar disk. AR4099 (S13E40,
beta), AR4100 (N07E55, beta-gamma), AR4101 (N03E44, beta) and
AR4102 (S22E03, beta) all showed spot development over the UT
day. As did AR4097 (S13W10, alpha) although this region is very
small. AR4100 was responsible for the long duration C5.0 flare
at 27/1012UT. All other sunspot regions are either stable or
in decay. Solar activity is expected to be at R1-R2 levels over
28-30 May. S0 solar radiation conditions were observed on 27-May
and S0 conditions are expected on 28-30 May. An east directed
CME is visible from 27/0936UT in SOHO and STEREO-A imagery, associated
with the long duration C5.0 flare. Analysis of this CME is ongoing,
however this event is not considered to be significantly geoeffective
due to it's location and direction. The solar wind speed on UT
day 27-May increased late in the day, ranging from 390 to 640
km/s and is currently near 570 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 14 nT and the north-south
IMF component (Bz) range was -9 to +3 nT. The recent increase
in solar wind speed is due to a small equatorial coronal hole
which has moved into a geoeffective position. A further, large
equatorial coronal hole is expected to enter a geoeffective position
on 28-May. The solar wind is expected to be elevated over 28-30
May.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 May: G0
Estimated Indices 27 May : A K
Australian Region 8 22122233
Cocos Island 6 21022232
Darwin 11 32122243
Townsville 8 22123232
Learmonth 8 22122233
Alice Springs 8 22122233
Gingin 8 21122233
Canberra 7 22123222
Kennaook Cape Grim 8 21123223
Hobart 8 21123223
Estimated Antarctic Regional K Indices 27 May :
Macquarie Island 11 21035222
Casey 11 32222333
Mawson 24 33333346
Observed Regional daily pc3 Indices 27 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 8 (Quiet)
Hobart 41 (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 27 May : A
Fredericksburg 13
Planetary 15
Observed AFr/Ap Indices 26 May : A K
Fredericksburg 8
Planetary 0 ---- ----
2B. MAGNETIC FORECAST
Date Ap Conditions
28 May 20 G1
29 May 18 G0, chance G1
30 May 10 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 27-May. G0-G2 conditions were observed in the
Antarctic region. G1 geomagnetic conditions are expected on 28-May
and G0 conditions, with a chance of G1 expected on 29-May due
to anticipated coronal hole high speed wind stream effects. G0
conditions are expected on 30-May.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 May Normal Normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 May Normal Normal-fair Fair
29 May Normal Normal-fair Fair
30 May Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 27-May were
mostly normal, with fair conditions at higher latitudes. HF radio
propagation conditions are expected to be mostly normal to fair
over 28-30 May, with degraded conditions possible at high latitudes.
Shortwave fadeouts are probable.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 May 86
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Depressed by 15% during local night.
Niue Island Region:
No data available during local day.
No data available during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 30% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 25% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Apr 123
May 113
Jun 111
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
28 May 75 15 to 20% below predicted monthly values
29 May 80 15 to 20% below predicted monthly values
30 May 80 15 to 20% below predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 27-May were near predicted monthly values to
30% depressed during local nights. Spread F was observed at Hobart,
Canberra, Townsville and Brisbane during local night hours. MUFs
are expected to be 15-20% depressed over 28-30 May. Shortwave
fadeouts are probable.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 May
Daily Proton Fluence >1 MeV: 4.2E+05
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 3.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B7.9
DSCOVR Satellite Solar Wind Day Averaged Data for 26 May
Speed: 435 km/sec Density: 4.7 p/cc Temp: 60200 K Bz: 0 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