[Ips-dsgr] ASWFC Daily Report - 22 May 25 issued 2330 UT on 22 May 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri May 23 09:30:43 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 MAY AND FORECAST FOR 23 MAY - 25 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 22 May:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 22 May: 120/72


1B. SOLAR FORECAST
             23 May             24 May             25 May
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   120/72             120/72             125/78

COMMENT: Solar activity on UT day 22-May was at the R0 level. 
There are currently eight numbered sunspot regions visible on 
the solar disk. AR4094 (N20E37, beta), AR4095 (S05W69, beta) 
and AR4097 (S13E60, beta) showed spot development over the UT 
day but there are currently no regions which are large or which 
have complex magnetic characteristics. All other sunspot regions 
are stable. Solar activity is expected to be at R0-R1 levels 
over 23-25 May. S0 solar radiation conditions were observed on 
22-May. S0 conditions are expected over 23-25 May. No Earth-directed 
CMEs have been observed. A northeast directed CME is visible 
in SOHO and STEREO-A imagery from 22/1548UT. This CME is associated 
with coronal movement, visible behind the eastern limb in GOES 
SUVI and SDO imagery from 22/1505UT. This event is farside and 
not geoeffective. The solar wind speed on UT day 22-May was in 
decline and mostly ranged between 450 to 590 km/s and is currently 
near 470 km/s. The peak total interplanetary magnetic field strength 
(IMF, Bt) was 9 nT and the north-south IMF component (Bz) range 
was -5 to +7 nT. The solar wind speed is expected to remain near 
current levels, with a possible slow decline over 23-25 May

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 22 May: G0

Estimated Indices 22 May : A   K           
   Australian Region       4   22211011
      Cocos Island         2   12210010
      Darwin               5   22211121
      Townsville           4   22211111
      Learmonth            4   22211111
      Alice Springs        3   22201010
      Gingin               3   22201011
      Canberra             3   22201011
      Kennaook Cape Grim   4   22211011
      Hobart               3   22201011    

Estimated Antarctic Regional K Indices 22 May :
      Macquarie Island     2   21002010
      Casey                8   33321121
      Mawson              19   34322254

Observed Regional daily pc3 Indices 22 May : 
      Darwin               4   (Quiet)
      Townsville           5   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              37   (Quiet to unsettled)
      Canberra            53   (Unsettled)
      Hobart              64   (Active)

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 22 May : A 
           Fredericksburg         7
           Planetary              9                         

Observed AFr/Ap Indices 21 May :  A   K
           Fredericksburg        12
           Planetary             12   4333 2122     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
23 May    10    G0
24 May     8    G0
25 May     5    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 22-May. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with G1 conditions observed 
at Mawson. G0 geomagnetic conditions are expected over 23-25 
May.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
23 May      Normal         Normal-fair    Normal-fair
24 May      Normal         Normal-fair    Normal-fair
25 May      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 22-May were 
mostly normal to fair with the poorest conditions in the northern 
hemisphere. HF radio propagation conditions are expected to be 
normal to fair over 23-25 May with conditions slowly improving 
over the period. Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
22 May    88

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values 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
23 May    90    Depressed 15%/near predicted monthly values
24 May    90    Depressed 15%/near predicted monthly values
25 May    90    Depressed 15%/near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 50 was issued on 
21 May and is current for 21-23 May. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 22-May were near predicted 
monthly values during local day with depressions of up to 25% 
during local night. Spread F was observed at Hobart, Brisbane 
and Darwin during local night hours. Sporadic E was also observed 
at Hobart and Cocos Islands during local night hours. MUFs are 
expected to be near predicted monthly values to 15% depressed 
over 23-25 May. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 21 May
       Daily Proton Fluence >1 MeV:   1.2E+05
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 3.60E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B4.7

DSCOVR Satellite Solar Wind Day Averaged Data for 21 May
Speed: 599 km/sec  Density:    1.3 p/cc  Temp:   218000 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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