[Ips-dsgr] ASWFC Daily Report - 31 March 25 issued 2330 UT on 31 Mar 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Tue Apr 1 10:30:57 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 MARCH AND FORECAST FOR 01 APRIL - 03 APRIL
STATUS INDICATORS SOL:** RED **   MAG:GREEN     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Mar:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.5 30/2319UT  possible   lower  West Pacific
  M1.2    1024UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Mar: 172/126


1B. SOLAR FORECAST
             01 Apr             02 Apr             03 Apr
Activity     R1-R2,chance R3    R1-R2,chance R3    R1-R2,chance R2
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   175/129            175/129            170/124

COMMENT: Solar activity on UT day 31-Mar was R1 due to an M1.2 
flare from AR4048 (S15E58, beta-gamma). This region also produced 
M1 flare activity late in the UT day yesterday. This region is 
reasonably large and continues to grow. In particular, the large 
umbra in the trailer spot of this region has changed shape considerably 
in the last 10 hours, possibly indicating magnetic instability. 
Smaller solar region AR4049 (S30E32, beta-gamma) is currently 
growing rapidly. The smaller surrounding spots around the large 
main spot of solar region AR4046 (N05E36, beta) have declined. 
Minor solar region AR4043 (N14W24, beta-gamma) has shown slight 
growth. Other regions are small and are either stable or in decay. 
There are currently seven numbered sunspot regions on the solar 
disk. Solar flare activity is expected to be R1-R2 over 01-03 
Apr. There is a chance for an isolated R3 flare from AR4048. 
No Earth-directed CMEs were observed in available imagery. A 
slow minor non Earth directed CME was observed to the northeast 
from 31/0624UT. S1 radiation storm conditions were observed from 
31/1425UT, with solar proton flux currently at 78PFU. The solar 
proton flux is possibly from the recent east limb X1 flare on 
28-Mar. S1, chance S2 solar radiation storm conditions are likely 
during 01-Apr, initially at S1 declining to S0 conditions are 
expected on 02-Apr and S0 conditions are expected on 03-Apr. 
The solar wind environment on UT day 31-Mar was variable and 
mildly enhanced with a small discontinuity observed from 31/1017UT, 
possibly a very weak signature from the recent eastward X1/CME. 
The solar wind speed ranged from 495 to 345 km/s and is currently 
near 446 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 12 nT and the north-south IMF component range (Bz) was 
+9 to -6 nT. A period of very mildly southward IMF conditions 
was observed 31/0735-1045UT. Small equatorial coronal holes are 
approaching the solar central meridian and may induce a mild 
increase in solar wind conditions in coming days.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 31 Mar: G0

Estimated Indices 31 Mar : A   K           
   Australian Region       4   12221101
      Cocos Island         4   12221110
      Darwin               5   22221102
      Townsville           5   22221211
      Learmonth            5   12231201
      Alice Springs        4   12221101
      Gingin               4   12221111
      Canberra             3   12221100
      Kennaook Cape Grim   4   12221200
      Hobart               3   12221100    

Estimated Antarctic Regional K Indices 31 Mar :
      Macquarie Island     3   01132100
      Casey               15   34432223
      Mawson               9   23322231

Observed Regional daily pc3 Indices 31 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               2   (Quiet)
      Canberra             6   (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 31 Mar : A 
           Fredericksburg         8
           Planetary              8                         

Observed AFr/Ap Indices 30 Mar :  A   K
           Fredericksburg         8
           Planetary             10   2221 2432     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
01 Apr    10    G0
02 Apr     8    G0
03 Apr     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic region on UT day 31-Mar. G0 geomagnetic conditions 
are exected over 01-03 Apr.

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

PCA Event : 10MeV Proton/PCA Event Began 31/1425UT and is in progress

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
01 Apr      Normal         Normal         Poor-fair
02 Apr      Normal         Normal         Normal-fair
03 Apr      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions were mostly normal on 
UT day 31-Mar, with a weak solar radiation storm slightly (0.5db) 
increasing absorption at polar latitudes. This S1-minor event 
is expected to end by 02-Apr. HF conditions at other latitudes 
are expected to be generally normal. Shortwave fadeouts are expected.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
31 Mar   150

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20-25%.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.
      Proton event in progress, increased absorption observed.

Monthly T index:
Month  T index
Feb      127
Mar      117
Apr      114

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
01 Apr   140    Near predicted monthly values to 15-20% enhanced.
02 Apr   140    Near predicted monthly values to 15-20% enhanced.
03 Apr   140    Near predicted monthly values to 15-20% enhanced.

COMMENT: ASWFC SWF HF Communications Warning 33 was issued on 
31 March and is current for 1-3 Apr. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 31-Mar were near predicted 
values to 25% enhanced. Ionospheric equatorial scintillation 
was observed in Weipa and Darwin during the interval 31/1127-1514UT. 
MUFs are generally expected to be near predicted values to 15-20% 
enhanced over 01-03 Apr. Shortwave fadeouts are expected on daylight 
HF circuits.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 30 Mar
       Daily Proton Fluence >1 MeV:   2.0E+06
       Daily Proton Fluence >10 MeV:  5.4E+04
       Daily Electron Fluence >2 MeV: 1.50E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.4

DSCOVR Satellite Solar Wind Day Averaged Data for 30 Mar
Speed: 449 km/sec  Density:    0.5 p/cc  Temp:    54600 K  Bz:   0 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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