[Ips-dsgr] ASWFC Daily Report - 28 March 26 issued 2331 UT on 28 Mar 2026 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sun Mar 29 10:31:30 AEDT 2026


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 MARCH 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 MARCH AND FORECAST FOR 29 MARCH - 31 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Mar:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.3    0418UT  possible   lower  E. Asia/Aust.

Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Mar: 162/116


1B. SOLAR FORECAST
             29 Mar             30 Mar             31 Mar
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            158/112            155/109

COMMENT: Solar activity on UT day 28-Mar was R1 due to an M1.3 
flare from AR4405 (S24E60, beta-gamma). The flare was a slow 
rise long duration event and had an associated CME. The small 
intermediate spots within this region have redistributed. Solar 
region AR4401 (N26W11, beta) was flare quiet and is showing decay 
in its trailer spots and redistribution in its leader spots. 
These two medium sized regions are the largest of the on disk 
regions. Smaller AR4404 (N17E54, beta) produced an isolated C4.1 
flare at 28/1135UT. There are currently eight solar regions on 
the visible solar disk. Most regions are smaller in size. All 
other sunspot regions are either stable or in decay. Solar activity 
is expected to be R0-R1 over 29-31 Mar. No Earth directed CMEs 
have been observed. A southeast directed CME associated with 
the M1.3 flare was observed from 28/0348UT in LASCO and 28/0442UT 
in STERE0-A space based coronagraph imagery and was modelled 
as an Earth miss, passing well behind the Earth. A very narrow 
faint northeast CME was observed from 28/1212UT and is not considered 
significant. S0 solar radiation storm conditions were observed 
on UT day 28-Mar. S0 solar radiation storm conditions are expected 
over 29-31 Mar. An isolated coronal hole is visible in the northwest 
solar quadrant and another is visible in the southeast solar 
quadrant. The solar wind speed on UT day 28-Mar was light to 
moderate. The solar wind ranged from 344 to 405 km/s and is currently 
at 359 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 7 nT and the north-south IMF component range (Bz) was 
+2 to -7 nT. The IMF Bz component was periodically mildly southward 
by up to -5nT during the UT day. From 28/2017UT a small increase 
was observed in the IMF total field to 7nT and the IMF became 
very steady with the Bz component also steady at -7nT southward 
for the interval 28/2017-2205UT. Whilst the increase in IMF Bt 
is small it may indicate an indistinct very weak CME transient, 
though other solar wind parameters did not show a deflection. 
The solar wind environment is expected to initially be near background 
levels early on 29-Mar. Solar wind 27 day recurrence patterns 
suggest that the coronal hole located in the northwest solar 
quadrant will moderately increase the solar wind speed from late 
in the UT day on 29-Mar to 31-Mar. The flux of electrons with 
an energy of greater than 2 MeV at geosynchronous orbit as measured 
by the US GOES satellite has been enhanced, which is statistically 
associated with the increased risk of geosynchronous satellite 
operational anomalies.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 28 Mar: G0

Estimated Indices 28 Mar : A   K           
   Australian Region       6   22221212
      Cocos Island         5   21221211
      Darwin               6   22221212
      Townsville           5   22221112
      Learmonth            -   --------
      Alice Springs        4   21221111
      Gingin               6   21221222
      Canberra             5   21221212
      Kennaook Cape Grim   6   22221222
      Hobart               6   22221212    

Estimated Antarctic Regional K Indices 28 Mar :
      Macquarie Island    12   22443211
      Casey               10   34221222
      Mawson              31   53333356

Observed Regional daily pc3 Indices 28 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth           NA
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               0   (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 28 Mar : A 
           Fredericksburg         9
           Planetary              9                         

Observed AFr/Ap Indices 27 Mar :  A   K
           Fredericksburg         6
           Planetary              7   2222 122-     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
29 Mar    13    G0, chance G1
30 Mar    19    G0-G1
31 Mar    15    G0, chance G1

COMMENT: ASWFC Geomagnetic Warning 21 was issued on 27 March 
and is current for 29-31 Mar. G0 geomagnetic conditions were 
observed in the Australian region on UT day 28-Mar. G0-G1 geomagnetic 
conditions were observed in the Antarctic region. The Earth is 
expected to enter a moderate coronal hole wind stream late on 
29-Mar with G0-G1 conditions likely 30-31 Mar. In addition, if 
the periodic mildly southward IMF conditions currently being 
observed persist, this may also induce a G1 period on 29-Mar.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
29 Mar      Normal         Normal-fair    Fair
30 Mar      Normal         Fair           Fair
31 Mar      Normal         Fair-normal    Fair

COMMENT: HF radio propagation on UT day 28-Mar were fair to normal, 
with fair conditions at middle to high latitudes. HF radio propagation 
conditions are expected to be initially normal on 29-Mar, then 
becoming fair. HF conditions may become mildly degraded during 
30-31 Mar at middle to high latitudes, particularly during local 
night hours. Isolated minor fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
28 Mar    94

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

Monthly T index:
Month  T index
Feb      98
Mar      87
Apr      85

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
29 Mar    90    Near predicted monthly values
30 Mar    80    Depressed 10 to 15%/near predicted monthly values
31 Mar    75    Depressed 10 to 15%/near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 28-Mar were generally near predicted values 
to 15% enhanced. 15% depressions were observed at times at Hobart 
during the local day. Southern Australian region MUFs were 15% 
depressed after local dawn this morning. Spread F was observed 
at Hobart during the local night. MUFs are expected to be near 
predicted monthly values for 29-Mar and 15% depressed to near 
predicted monthly values during 30-31 Mar in association with 
mild geomagnetic activity associated with a coronal hole wind 
stream. Isolated minor fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 27 Mar
       Daily Proton Fluence >1 MeV:   1.5E+06
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 3.10E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:19%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.1

DSCOVR Satellite Solar Wind Day Averaged Data for 27 Mar
Speed: 415 km/sec  Density:    0.2 p/cc  Temp:    58300 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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