[Ips-dsgr] ASWFC Daily Report - 15 May 25 issued 2331 UT on 15 May 2025 [SEC=OFFICIAL]

Fri May 16 09:31:24 AEST 2025

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/15 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 15 MAY AND FORECAST FOR 16 MAY - 18 MAY
STATUS INDICATORS SOL:** RED **   MAG:** YELLOW **     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 15 May:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M2.1    1721UT  possible   lower  South American/
                                    Atlantic

Observed 10.7 cm flux/Equivalent Sunspot Number for 15 May: 119/71

1B. SOLAR FORECAST
             16 May             17 May             18 May
Activity     R1-R2              R1-R2              R1-R2
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   118/70             118/70             118/70

COMMENT: Solar activity on UT day 15-May was at the R1 level 
due to an M2.1 flare at 15/1721UT produced by AR4087 (N15E37, 
beta-gamma-delta). There are currently two numbered sunspot regions 
visible on the solar disk and three unnumbered regions. AR4087 
is the most magnetically complex region on the disk and has exhibited 
spot development in its trailer spots over the UT day. AR4088 
(N08W50, beta) has shown decay in its trailer spots, whilst its 
leader spot has shown mild growth. An unnumbered region is visible 
near N28E24 (beta) and has shown mild growth. A second unnumbered 
region is visible near N13E68 (alpha) and has also shown mild 
growth. A third unnumbered region is visible near S13E75 (alpha) 
and is stable. Solar activity is expected to be at R1-R2 levels 
over 16-18 May. No Earth-directed CMEs have been observed. The 
solar wind speed on UT day 15-May was mostly stable, ranging 
from 415 to 480 km/s and is currently near 430 km/s. The peak 
total interplanetary magnetic field strength (IMF, Bt) was 9 
nT and the north-south IMF component (Bz) range was -6 to +5 
nT. A southern hemisphere coronal hole is currently crossing 
the central meridian and is expected to influence the solar wind 
speed on 18-May. The solar wind speed is expected to decline 
over 16-17 May, then increase on 18-May due to coronal hole effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 15 May: G0

Estimated Indices 15 May : A   K           
   Australian Region       7   22221312
      Cocos Island         6   22211311
      Darwin               8   22321322
      Townsville           9   23321322
      Learmonth            8   22222322
      Alice Springs        8   22321312
      Gingin               9   22222422
      Canberra             6   12221312
      Kennaook Cape Grim   8   23222312
      Hobart               8   23222312    

Estimated Antarctic Regional K Indices 15 May :
      Macquarie Island    17   23452421
      Casey               15   34233422
      Mawson              46   54432746

Observed Regional daily pc3 Indices 15 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              11   (Quiet)
      Canberra            10   (Quiet)
      Hobart              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 15 May : A 
           Fredericksburg        11
           Planetary             12                         

Observed AFr/Ap Indices 14 May :  A   K
           Fredericksburg        12
           Planetary              0   3223 4442     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
16 May     8    G0
17 May    10    G0
18 May    18    G0, chance of G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 15-May. Mostly G0-G1 geomagnetic conditions 
were observed in the Antarctic region, with isolated periods 
of G2 and G3 observed at Mawson. G0 geomagnetic conditions are 
expected over 16-18 May, with a chance of G1 on 18-May due to 
coronal hole high speed wind stream effects from a southern hemisphere 
coronal hole.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
15 May      Normal-fair    Normal-fair    Fair           

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
16 May      Normal         Normal         Normal-fair
17 May      Normal         Normal         Normal-fair
18 May      Normal         Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 15-May were 
fair at high latitudes, and normal to fair at middle and low 
latitudes. HF radio propagation conditions are expected to be 
mostly normal over 16-17 May, tending to normal to fair on 18-May. 
Shortwave fadeouts are probable.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
15 May    88

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 35% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

Monthly T index:
Month  T index
Apr      123
May      113
Jun      111

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
16 May    90    Depressed 15%/near predicted monthly values
17 May    90    Depressed 15%/near predicted monthly values
18 May    90    Depressed 15%/near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 47 was issued on 
14 May and is current for 14-16 May. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 15-May were depressed 
by 15-35% during local night and were near predicted monthly 
values during local day. Spread F was observed at Hobart and 
Brisbane during local night hours. MUFs are expected to be near 
predicted monthly values to 15% depressed over 16-18 May. Shortwave 
fadeouts are probable.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 14 May
       Daily Proton Fluence >1 MeV:   2.0E+06
       Daily Proton Fluence >10 MeV:  5.1E+04
       Daily Electron Fluence >2 MeV: 1.60E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.7

DSCOVR Satellite Solar Wind Day Averaged Data for 14 May
Speed: 401 km/sec  Density:    5.3 p/cc  Temp:    91500 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