[Ips-dsgr] ASWFC Daily Report - 25 May 24 issued 2330 UT on 25 May 2024 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sun May 26 09:30:47 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 MAY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 MAY AND FORECAST FOR 26 MAY - 28 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 May:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 25 May: 152/107


1B. SOLAR FORECAST
             26 May             27 May             28 May
Activity     R1,chance R2       R1,chance R2       R1,chance
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   145/99             145/99             150/105

COMMENT: Solar activity on UT day 25-May was at R0. Solar region 
AR3691(N26E63, beta-delta) is currently the largest region 
on the visible solar disk. Some development may have occurred 
in the leader spots of this region, with a small delta spot possibly 
emerging in one of the northern leader spots within this medium 
sized region. Current proximity to the eastern limb makes region 
evolution assessment difficult. This region has been flare quiet 
in the last 24 hours. Other regions of recent interest are AR3685(S14W46, 
beta), which has shown further decline in surrounding smaller 
spots, and smaller nearby AR3686(S08W34, beta-gamma) which has 
shown redistribution in its trailer spots. Solar region AR3686 
produced a minor C class flare. There are currently six numbered 
sunspot regions visible on the solar disk and one new unnumbered 
region. The new unnumbered region is a small emerging group of 
spots at S09E20. All other sunspot regions are either stable 
or in decay. Solar activity is expected to be at the R1 level 
over 26-28 May, with a chance of R2. A large previously flare 
active solar region (designated AR3664 on its previous disk transit) 
may return to the southeast solar limb on 27-May. No Earth directed 
CMEs have been observed. A slow faint west directed CME was observed 
in association with an erupting prominence on the western solar 
limb from 25/0438UT in SDO304 imagery. The solar wind speed on 
UT day 25-May was mostly steady, ranging from 346 to 444 km/s 
and is currently near 404 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 10 nT and the north-south IMF component 
(Bz) range was +5 to -7 nT. The solar wind speed may mildly increase 
over 26-28 May due to several mild coronal hole wind stream influences.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 25 May: G0

Estimated Indices 25 May : A   K           
   Australian Region       2   11200111
      Cocos Island         2   11100111
      Darwin               2   11200111
      Townsville           3   21201111
      Learmonth            4   12200212
      Alice Springs        2   11200110
      Gingin               3   11200212
      Canberra             2   11100111
      Kennaook Cape Grim   2   01100211
      Hobart               2   01100211    

Estimated Antarctic Regional K Indices 25 May :
      Macquarie Island     1   -1000111
      Casey                7   23311211
      Mawson               8   23202223

Observed Regional daily pc3 Indices 25 May : 
      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 25 May : A 
           Fredericksburg         7
           Planetary              7                         

Observed AFr/Ap Indices 24 May :  A   K
           Fredericksburg        11
           Planetary             11   3323 2212     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
26 May    12    G0
27 May    12    G0
28 May     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic region on UT day 25-May. G0 geomagnetic conditions 
are expected over 26-28 May, with a slight chance of G1 on 26-27 
May due to possible weak coronal hole influences.

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

PCA Event : No event.

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

COMMENT: HF radio communication conditions on UT day 25-May were 
mostly normal, with mild degradations at middle to high latitudes. 
Mostly normal HF conditions are expected over 26-28 May. Shortwave 
fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
25 May   123

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   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.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Apr      125
May      114
Jun      116

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
26 May   130    Near to 15% above predicted monthly values
27 May   130    Near to 15% above predicted monthly values
28 May   130    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 25-May were near predicted monthly values to 
15% enhanced. Spread F was observed at Hobart during local night 
hours. MUFs are expected to be near predicted monthly values 
to 15% enhanced over 26-28 May. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 24 May
       Daily Proton Fluence >1 MeV:   4.9E+05
       Daily Proton Fluence >10 MeV:  1.8E+04
       Daily Electron Fluence >2 MeV: 4.00E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.5

DSCOVR Satellite Solar Wind Day Averaged Data for 24 May
Speed: 376 km/sec  Density:    2.5 p/cc  Temp:    46700 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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