[Ips-dsgr] ASWFC Daily Report - 27 June 25 issued 2330 UT on 27 Jun 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sat Jun 28 09:30:58 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 JUNE 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 JUNE AND FORECAST FOR 28 JUNE - 30 JUNE
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Jun:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Jun: 118/70


1B. SOLAR FORECAST
             28 Jun             29 Jun             30 Jun
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   120/72             120/72             115/66

COMMENT: Solar activity on UT day 27-Jun was R0. There is currently 
no solar region of significance on the visible solar disk. All 
regions are relatively small. Solar region AR4122 (N13E31, beta) 
continues to grow, with small intermediate spots starting to 
emerge. Solar region AR4120 (N06W46, beta) has grown slightly. 
Solar region AR4117 (S14W53, beta) continues to slowly decay 
and solar region AR4118 (S13W44, beta) has now almost completely 
decayed. New small region AR4125 (N25E78, alpha) has rotated 
onto the disk. There are currently eight numbered sunspot regions 
on the solar disk. All other sunspot regions are either stable 
or in decay. A 15 degree long solar filament located at N22W70 
erupted at 27/1149UT. Solar activity is expected to be R0 over 
28-30 Jun. No significantly Earth directed CMEs have been observed. 
A northwest CME was observed in LASCO C2 imagery from 27/1200UT 
associated with the filament eruption in the northwest solar 
quadrant. This CME has been modelled as an Earth miss with the 
CME passing ahead of the Earth. S0 solar radiation storm conditions 
were observed on UT day 27-Jun. S0 solar radiation storm conditions 
are expected over 28-30 Jun. The solar wind speed is currently 
elevated due to a solar coronal hole wind stream from a coronal 
hole in the western solar hemisphere. The solar wind speed ranged 
from 806 to 660 km/s and is currently near 670 km/s. The peak 
total interplanetary field strength (IMF, Bt) was 6 nT and the 
north-south IMF component range (Bz) was +6 to -5 nT. The solar 
wind is expected to gradually decline in coming days.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 27 Jun: G0

Estimated Indices 27 Jun : A   K           
   Australian Region      11   33333121
      Cocos Island         7   32322011
      Darwin              11   33333122
      Townsville          11   32343111
      Learmonth           15   33434222
      Alice Springs       10   33333111
      Gingin              13   33334222
      Canberra            12   32443111
      Kennaook Cape Grim  16   33444221
      Hobart              18   33454221    

Estimated Antarctic Regional K Indices 27 Jun :
      Macquarie Island    23   44455211
      Casey               16   33335222
      Mawson              51   75543256

Observed Regional daily pc3 Indices 27 Jun : 
      Darwin               2   (Quiet)
      Townsville           4   (Quiet)
      Learmonth           14   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              99   (Minor storm)
      Canberra            85   (Minor storm)
      Hobart              87   (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 27 Jun : A 
           Fredericksburg        21
           Planetary             24                         

Observed AFr/Ap Indices 26 Jun :  A   K
           Fredericksburg        24
           Planetary             24   4343 4445     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
28 Jun    14    G0
29 Jun    10    G0
30 Jun     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 27-Jun. G0-G3 geomagnetic conditions were observed 
in the Antarctic region. G0 geomagnetic conditions are generally 
expected over 28-30 Jun. Whilst the solar wind is currently strong 
little geomagnetic activity is being induced as the interplanetary 
magnetic field is small (current IMF Bt magnitude of 3nT).

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
27 Jun      Normal         Fair-normal    Poor-fair      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
28 Jun      Normal         Fair-normal    Fair
29 Jun      Normal         Fair-normal    Fair-normal
30 Jun      Normal         Fair-normal    Fair-normal

COMMENT: HF radio propagation conditions were poor to normal 
on UT day 27-Jun, with degraded conditions at high latitudes 
at times. HF radio propagation conditions are expected to be 
fair to normal for 28-30 Jun. HF conditions for middle to high 
latitudes are expected to gradually improve.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
27 Jun    74

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Depressed by 15% during local day.
      Depressed by 35% during local night.
      Depressed by 30% after local dawn.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 45% over the UT day.

Monthly T index:
Month  T index
May      94
Jun      109
Jul      107

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
28 Jun    85    Depressed 15 to 25%/near predicted monthly values
29 Jun    85    Depressed 15 to 25%/near predicted monthly values
30 Jun    85    Depressed 15 to 25%/near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 27-Jun were 35% depressed to near predicted 
values. Spread-F was observed at Townsville and Hobart during 
local night hours. Persistent blanketing sporadic E was observed 
at Mawson in Antarctica. MUFs are expected to be near predicted 
values to 15-25% depressed over 28-30 Jun.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 26 Jun
       Daily Proton Fluence >1 MeV:   2.7E+05
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 1.20E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B4.9

DSCOVR Satellite Solar Wind Day Averaged Data for 26 Jun
Speed: 683 km/sec  Density:    2.5 p/cc  Temp:   374000 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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