[Ips-dsgr] ASWFC Daily Report - 08 April 25 issued 2330 UT on 08 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Apr 9 09:30:57 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/08 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 08 APRIL AND FORECAST FOR 09 APRIL - 11 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 08 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.5    2222UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 08 Apr: 159/113


1B. SOLAR FORECAST
             09 Apr             10 Apr             11 Apr
Activity     Low to moderate    Low to moderate    Low to moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   150/105            150/105            140/94

COMMENT: Solar activity on UT day 8-Apr was R1, with an isolated
 M1 flare from AR4048 (S15W59, beta-gamma). There are currently seven 
numbered sunspots on the solar disk. The most dominant spot, AR4048  
has decayed over the past day. AR4054 (S12W28, beta) and AR4055 
(N06W03, beta) has both grown and appeared to have reached maturity 
in the past day. All other sunspot regions are stable. Solar 
activity is expected to be R0-R1 over 9-11 Apr.

 A CME was observed from 0600 UT from near AR4057 (N08E42, alpha) 
associated with a filament eruption. Two others were observed off the
 eastern limb, likely farside. None of these CMEs are expected to be
 geoeffective. 

S0 solar radiation storm conditions were observed on UT day 8-Apr. 
S0 solar radiation storm conditions are expected over 9-11 Apr. 

The solar wind environment on UT day 9-Apr was mildly disturbed 
due to coronal hole effects. The solar wind speed was trending 
down from 450 km/s before connecting with a coronal hole and 
reached a peak of 563 km/s. The peak total interplanetary field 
strength (IMF, Bt) was 11 nT and the north-south IMF component 
range (Bz) was +11 to -11 nT with a brief 20 minute period of 
southward Bz at 1240 UT. The solar wind is expected to remain 
enhanced over 9-11 Apr, but possibly fluctuating, as there are 
two coronal holes with possible connection over the period.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 08 Apr: G0

Estimated Indices 08 Apr : A   K           
   Australian Region      14   23324333
      Cocos Island        13   23323333
      Darwin              13   32323333
      Townsville          15   33324333
      Learmonth           18   33324344
      Alice Springs       13   22324333
      Gingin              23   22324455
      Canberra            14   23324333
      Kennaook Cape Grim   -   --------
      Hobart              14   13324333    

Estimated Antarctic Regional K Indices 08 Apr :
      Macquarie Island    20   23425433
      Casey               29   54434345
      Mawson              70   46634386

Observed Regional daily pc3 Indices 08 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               2   (Quiet)
      Canberra            13   (Quiet)

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 08 Apr : A 
           Fredericksburg        17
           Planetary             25                         

Observed AFr/Ap Indices 07 Apr :  A   K
           Fredericksburg        10
           Planetary             13   3322 2243     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
09 Apr    20    G0-G1, chance G2
10 Apr    15    G0-G1
11 Apr    18    G0-G1

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 8-Apr, while a single period 
of G1 was observed in the planetary scale due to a very brief 
period of southward solar wind parameter Bz. G0-G1 geomagnetic 
conditions are expected over 9-11 Apr due to connection to two 
coronal holes in close proximity. There may be a slight chance 
for G2 over this period.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
09 Apr      Normal         Normal-fair    Fair
10 Apr      Normal         Normal         Fair
11 Apr      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions were generally normal 
at low and middle latitudes, with some degradations in high latitudes. 
Heavier degradations set in after 1500 UT. HF radio propagation 
conditions are expected to fluctuate from normal to fair over 
9-11 Apr due to two coronal holes.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
08 Apr   124

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 20% during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% 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
09 Apr   125    Near predicted monthly values to 15% depressed
10 Apr   120    Near predicted monthly values to 15% depressed
11 Apr   115    Near predicted monthly values to 15% depressed

COMMENT: ASWFC SWF HF Communications Warning 35 was issued on 
8 April and is current for 9-10 Apr. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 8-Apr were near predicted 
values. Spread-F was observed in Perth during local pre-dawn 
hours. MUFs are expected to be near predicted values 15% depressed 
over 9-11 Apr.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 07 Apr
       Daily Proton Fluence >1 MeV:   1.0E+06
       Daily Proton Fluence >10 MeV:  2.3E+04
       Daily Electron Fluence >2 MeV: 5.50E+08   (high fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:24%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.3

DSCOVR Satellite Solar Wind Day Averaged Data for 07 Apr
Speed: 526 km/sec  Density:    0.4 p/cc  Temp:   145000 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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