[Ips-dsgr] ASWFC Daily Report - 05 April 25 issued 2333 UT on 05 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sun Apr 6 09:33:52 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/05 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 05 APRIL AND FORECAST FOR 06 APRIL - 08 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: ** RED **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 05 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.0    2005UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 05 Apr: 184/137


1B. SOLAR FORECAST
             06 Apr             07 Apr             08 Apr
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   180/133            175/129            165/119

COMMENT: Solar activity on UT day 05-Apr was R1 due to an isolated 
M1 flare from solar region AR4048 (S15W12, beta-gamma). This 
region appears to be declining and has recently increased in 
magnetic complexity, though these mixed polarity fields are small 
and weak. Solar region AR4046 (N05W32, alpha) also flared at 
near the same time so there is some ambiguity with the solar 
region of origin of this flare. Smaller solar region AR4054 (S12E13, 
beta) is growing. There are currently ten numbered sunspots on 
the solar disk. All other sunspot regions are either stable or 
in decay. Solar activity is expected to be R0-R1 over 06-08 Apr. 
Solar activity was observed on the northeast solar limb early 
in the UT day. Plasma emission and loop structures were visible 
in SDO193 imagery from 05/0656UT. A possible erupting prominence 
was visible in SDO304 from 05/0600UT on the northeast limb at 
solar latitude N40. No Earth directed CMEs were observed on UT 
day 05-Apr. A large CME was observed off the northeast solar 
limb from 05/0412UT. Due to the on/behind the eastern solar limb 
location of this CME event it is not expected to be significantly 
geoeffective. S0 solar radiation storm conditions were observed 
on UT day 05-Apr. S0 solar radiation storm conditions are expected 
over 06-08 Apr. The solar wind speed on UT day 05-Apr further 
increased and ranged from 550 to 700 km/s. The solar wind speed 
is currently near 580 km/sec. The solar wind data was noisy making 
true speed assessment difficult. The increase in wind speed is 
due to a solar coronal hole located now well west of the solar 
central meridian in the northwest solar quadrant. The peak total 
interplanetary magnetic field strength (IMF, Bt) was 12 nT and 
the north-south IMF component (Bz) range was +9 to -11 nT. The 
solar wind speed is now expected to be moderate to be moderate 
to strong on 06-Apr and then declining to background conditions 
on 07-Apr. Solar 27 day recurrent patterns of the IMF Bz component 
suggest that southward IMF conditions may be expected during 
08-09 Mar. These conditions on the past two rotations have been 
followed by a moderate elevation in solar wind speed over 09-11 
Mar associated with a coronal hole. However, the current on disk 
coronal hole structures appear somewhat different on this solar 
rotation reducing confidence in this 27 day persistence forecast 
of southward IMF conditions for this solar rotation.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 05 Apr: G0

Estimated Indices 05 Apr : A   K           
   Australian Region      19   33344343
      Cocos Island        15   34333332
      Darwin              17   33344332
      Townsville          25   43445343
      Learmonth           27   34454353
      Alice Springs       22   33445333
      Gingin              27   43354453
      Canberra            19   33344343
      Kennaook Cape Grim  25   34454343
      Hobart              23   34354343    

Estimated Antarctic Regional K Indices 05 Apr :
      Macquarie Island    52   45575553
      Casey               26   45543333
      Mawson              76   75664575

Observed Regional daily pc3 Indices 05 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            2   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              44   (Unsettled)
      Canberra            38   (Quiet to 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 05 Apr : A 
           Fredericksburg        32
           Planetary             44                         

Observed AFr/Ap Indices 04 Apr :  A   K
           Fredericksburg        19
           Planetary             33   4444 4545     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
06 Apr    16    G1, declining to G0
07 Apr     8    G0
08 Apr    17    G0, chance G1 late in UT day

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 05-Apr. In the Antarctic region G1-G3 conditions 
were observed at Macquarie Island and Maswon and G1 conditions 
observed at Casey. A single period G2 planetary geomagnetic conditions 
was observed early in the UT day. Two periods G1 planetary conditions 
were also observed. G1 geomagnetic conditions are initially expected 
on 06-Apr due to a wind stream from a small equatorial coronal 
hole, then declining to G0. G0 conditions are expected on 07-Apr. 
A 27 day recurrent interplanetary magnetic field pattern of southward 
IMF Bz conditions which has preceded a moderate speed coronal 
hole wind pattern on previous rotations, suggests that G1, chance 
G2 conditions may be experienced over 8-9 Mar, however coronal 
hole structures appear different on this rotation.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 05-Apr were 
fair to normal, with degraded conditions at middle to high latitudes. 
HF radio propagation conditions are expected to be fair on 06-Apr 
for middle to high latitudes. Normal conditions are expected 
to low latitudes. Improved HF conditions expected for 07-Apr.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
05 Apr   129

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 20% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
      Depressed by 30% after local dawn.
   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
06 Apr    70    Depressed 15 to 30%/near predicted monthly values
07 Apr   125    Near predicted monthly values
08 Apr   125    Near predicted monthly values

COMMENT: ASWFC HF Communications Warning 34 was issued on 5 April 
and is current for 6 Apr only. Maximum usable frequencies (MUFs) 
in the Australian region on UT day 05-Apr were initially near 
predicted values to 15% enhanced. However, Hobart was 30% depressed 
early in the UT day on 05-Apr during the interval 05/000-0300UT. 
Southern Australian region MUFs are depressed 30% after local 
dawn this morning. Strong spread F was observed at Hobart during 
local night hours. Southern Australian region MUFs are expected 
to be depressed 30% for the local day today. Northern Australian 
region MUFs are expected to be near predicted monthly values 
to 15% enhanced.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 04 Apr
       Daily Proton Fluence >1 MeV:   1.1E+07
       Daily Proton Fluence >10 MeV:  4.1E+04
       Daily Electron Fluence >2 MeV: 6.00E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.3

DSCOVR Satellite Solar Wind Day Averaged Data for 04 Apr
Speed: 505 km/sec  Density:   10.9 p/cc  Temp:   295000 K  Bz:  -4 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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