[Ips-dsgr] ASWFC Daily Report - 26 December 24 issued 2330 UT on 26 Dec 2024 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Dec 27 10:30:43 AEDT 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 DECEMBER AND FORECAST FOR 27 DECEMBER - 29 DECEMBER
STATUS INDICATORS SOL:** RED **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Dec:  R2

Flares    Max     Fadeout    Freq.  Sectors
  M3.0    0030UT  possible   lower  West Pacific
  M7.3    0315UT  probable   lower  E. Asia/Aust.

Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Dec: 256/206


1B. SOLAR FORECAST
             27 Dec             28 Dec             29 Dec
Activity     R1-R2, chance R3   R1-R2, chance R3   R1-R2, chance R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   255/205            260/210            255/205

COMMENT: Solar activity on UT day 26-Dec was at the R2 level 
due to an M7.4 flare at 26/0315UT, an M3.1 flare was also observed 
at 26/0030UT. There were eleven numbered active sunspot regions 
visible on the solar disk on 26-Dec. Both M-class flares of the 
UT day were produced by two regions concurrently, therefore AR3933 
(S09W28, beta-gamma-delta), AR3936 (N10W01, beta) and AR3938 
(N17E37, beta-gamma) were responsible for the notable flares 
on 26-Dec. AR3936 showed trailer development over the UT day, 
AR3932 (S17W14, beta-gamma) also showed spot development. Four 
regions, AR3928 (S15W32, beta-gamma), AR3932, AR3933 and AR3938, 
are magnetically complex. All other active regions were either 
stable or in decline. Solar activity is expected to be at R1-R2 
levels, with a chance of R3 flaring over 27-29 Dec. S0 solar 
radiation storm conditions were observed on UT day 26-Dec, the 
>10 MeV proton flux as measured at GOES was elevated but in decline 
over the UT day. S0 solar radiation storm conditions, with a 
chance of S1 are expected over 27-29 Dec. Several CMEs were observed 
on 26-Dec, but none are considered geoeffective. The solar wind 
speed was in decline over the UT day ranging between 340 and 
450 km/s. The solar wind speed is currently at around 355 km/s. 
The peak total interplanetary field strength (IMF, Bt) was 4 
nT and the north-south IMF component range (Bz) was +3 to -3 
nT. The CME which was expected to impact with Earth on 25-26 
Dec appears to have passed by with no impact. The solar wind 
speed is expected to decline towards background levels over 27-29 
Dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 26 Dec: G0

Estimated Indices 26 Dec : A   K           
   Australian Region       1   12000001
      Cocos Island         1   12010000
      Darwin               1   12000001
      Townsville           2   21000012
      Learmonth            1   11000001
      Alice Springs        1   12000001
      Gingin               0   02000000
      Canberra             1   12000001
      Kennaook Cape Grim   2   12100001
      Hobart               1   11100000    

Estimated Antarctic Regional K Indices 26 Dec :
      Macquarie Island     0   00000000
      Casey                7   23322111
      Mawson               5   12211212

Observed Regional daily pc3 Indices 26 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             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 26 Dec : A 
           Fredericksburg         5
           Planetary              7                         

Observed AFr/Ap Indices 25 Dec :  A   K
           Fredericksburg         5
           Planetary              4   1111 1101     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
27 Dec     5    G0
28 Dec     5    G0
29 Dec     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 26-Dec. G0 geomagnetic conditions 
are expected on 27-29 Dec.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
27 Dec      Normal         Normal         Normal
28 Dec      Normal         Normal         Normal
29 Dec      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 26-Dec were 
mostly normal to fair, with degradations at high latitudes mostly 
in the second half of the UT day. HF radio propagation conditions 
are expected to be mostly normal on 27-29 Dec. Shortwave fadeouts 
are probable.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
26 Dec   151

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 55% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
      Enhanced by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Nov      127
Dec      117
Jan      114

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
27 Dec   150    Near to 15% above predicted monthly values
28 Dec   150    Near to 15% above predicted monthly values
29 Dec   150    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 26-Dec were near predicted values to 20% enhanced 
during local night, with stronger enhancements in the southern 
Australian region. Sporadic-E was observed during local night 
hours at Hobart, Canberra, Perth and Brisbane. MUFs are expected 
to be near predicted monthly values to 15% enhanced on 27-29 
Dec. Shortwave fadeouts are probable.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 25 Dec
       Daily Proton Fluence >1 MeV:   5.8E+05
       Daily Proton Fluence >10 MeV:  1.1E+05
       Daily Electron Fluence >2 MeV: 2.90E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C2.6

DSCOVR Satellite Solar Wind Day Averaged Data for 25 Dec
Speed: 476 km/sec  Density:    2.4 p/cc  Temp:    95400 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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