[Ips-dsgr] ASWFC Daily Report - 26 May 23 issued 2331 UT on 26 May 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat May 27 09:31:10 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 MAY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 MAY AND FORECAST FOR 27 MAY - 29 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 May:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.3    2303UT  possible   lower  West Pacific

Observed 10.7 cm flux/Equivalent Sunspot Number for 26 May: 149/104


1B. SOLAR FORECAST
             27 May             28 May             29 May
Activity     R0-R1,chance R2    R0-R1,chance R2    R0-R1,chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   148/102            148/102            145/99

COMMENT: Solar activity on UT day 26-May was at the R1 level, 
due to an M1.3 flare at 26/2304UT from AR3311(N18W32, beta). 
Solar region AR3314(N12W43, beta) produced a C5.5 flare at 26/1754UT. 
Solar region AR3315(S17E08, beta) produced several low level 
C flares. Other regions currently on disk remained flare quiet. 
There are currently 7 numbered sunspot regions on the solar disk. 
Solar region AR3315 continues to show development. Solar region 
AR3311(N18W30, beta) continues to decline. The other solar regions 
exhibited only minor changes. Old solar region AR3296 (N15) which 
produced M-flare(s) on its previous solar transit may return 
on 27 May (though there is currently no sign of anything that 
significant on the NE limb). Solar activity is expected to be 
at R0-R1, with a slight chance of an R2 flare over 27-29 May. 
A small erupting solar prominence was observed near/on the western 
solar limb at S10 at 26/0253UT. Some solar filament motion activity 
was observed at S05E05 at 16/1503UT, N27E20 at 26/1538UT and 
S15W25 at 26/2041UT but with no eruptions clearly apparent. No 
Earth directed CMEs have been observed. A westward CME was observed 
in association with western solar limb prominence activity at 
26/0312UT, and a southward faint CME was observed from 26/1948UT, 
both events are considered as not Earth directed. The southward 
CME could not be correlated to any on disk activity. The solar 
wind speed on UT day 26-May showed a declining trend and ranged 
from 573 to 396 km/s, and is currently near 415 km/s. The peak 
total interplanetary field strength (IMF, Bt) was 5 nT and the 
north-south IMF component range was +5 to -5 nT. The solar wind 
speed is expected to continue to decrease to background levels 
as coronal hole wind stream effects wane. A small coronal hole 
is at the solar meridian at solar latitude N40, though moderately 
high in latitude and rather small this hole may produce a very 
mild increase in solar wind speed in 3-4 days time. There is 
a slight chance for a very weak CME transient signature in the 
solar wind parameters on 29-May from the M1/CME on 25-May.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 26 May: G0

Estimated Indices 26 May : A   K           
   Australian Region       4   22210211
      Cocos Island         3   22210000
      Darwin               3   21210111
      Townsville           4   22200211
      Learmonth            4   22210211
      Alice Springs        3   22200201
      Gingin               5   22210212
      Canberra             3   22100201
      Hobart               3   22200201    

Estimated Antarctic Regional K Indices 26 May :
      Macquarie Island     3   22200200
      Casey                9   33321221
      Mawson              18   44331125

Observed Regional daily pc3 Indices 26 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             6   (Quiet)
      Hobart              14   (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 May : A 
           Fredericksburg         6
           Planetary              6                         

Observed AFr/Ap Indices 25 May :  A   K
           Fredericksburg        11
           Planetary             10   3233 3222     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
27 May     8    G0
28 May     6    G0
29 May    13    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 26-May. G0 geomagnetic conditions 
are expected over 27-29 May. There is a slight chance for a very 
weal glancing blow from a CME on 29-May.

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

PCA Event : No event.

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

COMMENT: HF communication conditions on UT day 26-May were generally 
normal, with some mild degradations observed at middle to high 
latitudes during local night hours. HF communication conditions 
are expected to be mostly normal over 27-29 May. Isolated shortwave 
fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
26 May    82

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

Monthly T index:
Month  T index
Apr      120
May      87
Jun      88

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
27 May    95    Near predicted monthly values
28 May    95    Near predicted monthly values
29 May    95    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 51 was issued on 
25 May and is current for 26-28 May. Maximum usable frequencies 
(MUFs) on UT day 26-May were generally near predicted monthly 
values in the Australian region, with depressions of up to 20% 
observed during local night hours. Spread-F was observed in Townsville, 
Brisbane, Canberra and Hobart during local night hours. Sporadic 
E was occasionally observed at Darwin. MUFs are expected to be 
near predicted monthly values over 27-29 May. Isolated shortwave 
fadeouts are possible. A minor fadeout impacting lower HF frequencies 
associated with the M1 flare was observed at Niue at the time 
of issue of this report.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 25 May
       Daily Proton Fluence >1 MeV:   4.1E+04
       Daily Proton Fluence >10 MeV:  2.3E+04
       Daily Electron Fluence >2 MeV: 1.40E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B8.7

DSCOVR Satellite Solar Wind Day Averaged Data for 25 May
Speed: 578 km/sec  Density:    0.9 p/cc  Temp:   268000 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



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