[Ips-dsgr] ASWFC Daily Report - 30 May 25 issued 2335 UT on 30 May 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sat May 31 09:35:40 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/30 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 30 MAY AND FORECAST FOR 31 MAY - 02 JUNE
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 30 May:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M3.4    0613UT  possible   lower  Mid East/Indian
  M1.6    1839UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 30 May: 157/111


1B. SOLAR FORECAST
             31 May             01 Jun             02 Jun
Activity     R1-R2              R1-R2              R1-R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   155/109            150/105            145/99

COMMENT: Solar activity on UT day 30-May was at the R1 level 
due to an M3.4 flare at 30/0613UT and an M1.6 flare at 30/1845UT. 
There are currently six numbered sunspot regions visible on the 
solar disk. AR4100 (N07E15, gamma-delta), AR4101 (N03E04, beta-gamma) 
and AR4104 (N05E44, beta-gamma) showed spot development. AR4101 
and AR4104 may have small delta spots in addition to AR4099 (S14E01, 
beta-delta) (in decay) and AR4100. AR4100 and AR4014 were responsible 
for the two M-Class flares of the UT day respectively. All other 
sunspot regions are stable. Solar activity is expected to be 
at R1-R2 levels over 31-May to 02-Jun. No Earth-directed CMEs 
have been observed. A small, northwest directed CME is visible 
from 30/0048UT in SOHO and STEREO-A imagery. This CME is not 
expected to be geoeffective. An east directed, partial halo CME 
is visible in SOHO and STEREO-A imagery from 30/0712UT. This 
event is associated with an eruption from 30/0610UT aound N03E20, 
visible in SDO, GOES SUVI and H-Alpha imagery. This eruption 
is associated with the M3.4 flare at 30/0613UT. Modelling suggests 
this CME will pass behind the Earth. There is a possible second 
CME on the same line as the above CME, visible from 30/1248UT 
in SOHO and STEREO-A imagery. Modelling suggests this CME will 
also pass behind the Earth. The solar wind speed on UT day 30-May 
was steady, ranging from 630 to 830 km/s and is currently near 
730 km/s. The peak total interplanetary magnetic field strength 
(IMF, Bt) was 8 nT and the north-south IMF component (Bz) range 
was -6 to +7 nT. The solar wind speed is expected to remain elevated 
over 31-May to 02-Jun due to coronal hole high speed wind stream 
effects from an equatorial coronal hole. A decline is possible 
on 02-Jun.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 30 May: G0

Estimated Indices 30 May : A   K           
   Australian Region      21   43434433
      Cocos Island        14   33323432
      Darwin              19   44333433
      Townsville          16   43333333
      Learmonth           26   44434543
      Alice Springs       16   43333333
      Gingin              26   44434543
      Canberra            18   43434332
      Kennaook Cape Grim  24   43444443
      Hobart              24   43444443    

Estimated Antarctic Regional K Indices 30 May :
      Macquarie Island    46   45566543
      Casey               39   44433573
      Mawson              61   66554566

Observed Regional daily pc3 Indices 30 May : 
      Darwin              14   (Quiet)
      Townsville           0   (Quiet)
      Learmonth           19   (Quiet)
      Alice Springs        8   (Quiet)
      Gingin              83   (Minor storm)
      Canberra            83   (Minor storm)
      Hobart             151   (Severe 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 30 May : A 
           Fredericksburg        28
           Planetary             36                         

Observed AFr/Ap Indices 29 May :  A   K
           Fredericksburg        33
           Planetary              0   7555 6665     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
31 May    18    G0, chance G1
01 Jun    12    G0
02 Jun     8    G0

COMMENT: Mostly G0 geomagnetic conditions were observed in the 
Australian region during the UT day 30-May. Periods of G1 activity 
were observed at Learmonth and Gingin. Mostly G2 geomagnetic 
conditions were observed in the Antarctic region, with an isolated 
period of G3 observed at Casey. G0 geomagnetic conditions, with 
a chance of G1 are expected on 31-May. G0 geomagnetic conditions 
are expected over 01-02 Jun.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
30 May      Fair           Fair-poor      Poor           

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
31 May      Normal         Normal-fair    Fair
01 Jun      Normal         Normal         Normal-fair
02 Jun      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 30-May were 
mostly fair to poor. HF radio propagation conditions are expected 
to be mostly fair on 31-May and normal to fair over 01-02 Jun. 
Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
30 May    86

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% 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:
      Depressed by 15% during local day.
      Depressed by 15% during local night.
      Depressed by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% 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
31 May    80    5 to 15% below predicted monthly values
01 Jun    95    Near predicted monthly values
02 Jun    95    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the southern Australian 
region on UT day 30-May were depressed by up to 25%. MUFs in 
the northern Australian region were near predicted monthly values 
to depressed by up to 30%. Spread F was observed at Hobart and 
Canberra during local night hours. Sporadic E was observed at 
Cocos Islands during much of the UT day. MUFs are expected to 
be near predicted monthly values over 31-May to 02-Jun, with 
depressions of up to 15% possible on 31-May. Shortwave fadeouts 
are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 29 May
       Daily Proton Fluence >1 MeV:   2.4E+06
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 1.90E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.9

DSCOVR Satellite Solar Wind Day Averaged Data for 29 May
Speed: 677 km/sec  Density:    3.2 p/cc  Temp:   360000 K  Bz:  -1 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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