[Ips-dsgr] ASWFC Daily Report - 06 April 25 issued 2330 UT on 06 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Mon Apr 7 09:30:55 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/06 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 06 APRIL AND FORECAST FOR 07 APRIL - 09 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 06 Apr:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 06 Apr: 167/121


1B. SOLAR FORECAST
             07 Apr             08 Apr             09 Apr
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   165/119            160/114            150/105

COMMENT: Solar activity on UT day 06-Apr was R0. Solar region 
AR4048 (S15W29, beta) which is currently the largest on disk 
region continues to decay. Solar region AR4054 (S12E02, beta) 
is growing rapidly. Solar region AR4046 (N05W44, alpha) has been 
stable. There are currently nine numbered sunspots on the solar 
disk. All other sunspot regions are small and are either stable 
or in decay. An area of emission is visible in SDO193 imagery 
at solar latitude N12 on the eastern solar limb but currently 
does not appear to be large. Solar activity is expected to be 
R0-R1 over 07-09 Apr. An R1 flare is possible from region AR4054. 
No Earth directed CMEs were observed on UT day 06-Apr. Non Earth 
directed CMEs were observed to the north from 06/0412UT and southeast 
from 06/0812UT. S0 solar radiation storm conditions were observed 
on UT day 06-Apr, with a minor enhancement in proton flux of 
0.95PFU observed late in the UT day, possibly from yesterday's 
eastward CME. S0 solar radiation storm conditions are expected 
over 07-09 Apr. The solar wind speed on UT day 06-Apr was mostly 
elevated and steady with a declining trend late in the UT day 
and ranged from 575 km/sec to 727 km/sec. The solar wind speed 
is currently near 580 km/sec. The elevated wind speed is due 
to a solar coronal hole wind stream. The peak total interplanetary 
magnetic field strength (IMF, Bt) was 8 nT and the north-south 
IMF component (Bz) range was +7 to -6 nT. The solar wind speed 
is expected to slowly decline on 07-Apr. Another coronal hole 
located in the southeast solar quadrant is approaching the solar 
central meridian. Solar 27 day recurrent patterns of the IMF 
Bz component suggest that periods of southward IMF conditions 
may be expected on 08-09-Apr, followed by a moderate elevation 
in solar wind speed over 10-11 Apr associated with this coronal 
hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 06 Apr: G0

Estimated Indices 06 Apr : A   K           
   Australian Region      13   32233342
      Cocos Island        11   32232332
      Darwin              13   32233342
      Townsville          17   33243343
      Learmonth           23   53233453
      Alice Springs       14   32233343
      Gingin              20   52233443
      Canberra            15   32243342
      Kennaook Cape Grim  15   32243342
      Hobart              15   32243342    

Estimated Antarctic Regional K Indices 06 Apr :
      Macquarie Island    26   33455442
      Casey               32   55643333
      Mawson              65   75544755

Observed Regional daily pc3 Indices 06 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            4   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              42   (Unsettled)
      Canberra            44   (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 06 Apr : A 
           Fredericksburg        18
           Planetary             21                         

Observed AFr/Ap Indices 05 Apr :  A   K
           Fredericksburg         0
           Planetary              0   4544 3333     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
07 Apr     8    G0
08 Apr    15    G0, chance G1 late in UT day
09 Apr    20    G1, chance G2

COMMENT: ASWFC Geomagnetic Warning 26 was issued on 6 April and 
is current for 9-10 Apr. G0 geomagnetic conditions were observed 
in the Australian region on UT day 06-Apr. In the Antarctic region 
G3 periods were observed at Mawson and G1-G2 periods were observed 
at Casey and G1 conditions were observed at Macquarie Island. 
A single period of G1 planetary geomagnetic conditions was observed 
early in the UT day. G0 conditions are expected on 07-Apr and 
are also generally expected on 08-Apr. A 27 day recurrent interplanetary 
magnetic field pattern of southward IMF Bz conditions suggests 
an increase in geomagnetic activity to G1, chance G2 conditions 
for 09-Apr.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
06 Apr      Normal         Fair           Fair-poor      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
07 Apr      Normal         Normal         Normal-fair
08 Apr      Normal         Normal         Normal-fair
09 Apr      Normal         Fair-normal    Fair

COMMENT: HF radio propagation conditions on UT day 06-Apr were 
normal to poor, with degraded conditions at middle to high latitudes. 
HF radio propagation conditions are expected to be fair to normal 
on 07-Apr, with fair conditions expected for high latitudes and 
normal conditions expected for low to middle latitudes.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
06 Apr   112

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 30% during local day.
      Enhanced by 15% during local night.
   Niue Island Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Depressed by 20% 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
Mar      126
Apr      115
May      113

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
07 Apr   125    Near predicted monthly values
08 Apr   125    Near predicted monthly values
09 Apr   125    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 06-Apr were depressed 20% in the southern Australian 
region and near predicted monthly values in the northern Australian 
region. MUFs at Perth were depressed 50% early in UT day. Strong 
spread F was observed at Hobart during local night hours. Sporadic 
E was observed at east coast sites during local night hours. 
MUFs are expected to be near predicted monthly values 07-09 Apr.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 05 Apr
       Daily Proton Fluence >1 MeV:   3.4E+06
       Daily Proton Fluence >10 MeV:  1.8E+04
       Daily Electron Fluence >2 MeV: 4.70E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.6

DSCOVR Satellite Solar Wind Day Averaged Data for 05 Apr
Speed: 549 km/sec  Density:    1.3 p/cc  Temp:    18700 K  Bz:  -3 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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