[Ips-dsgr] ASWFC Daily Report - 27 May 23 issued 2331 UT on 27 May 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sun May 28 09:31:08 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 MAY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 MAY AND FORECAST FOR 28 MAY - 30 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 May:  R0 

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 27 May: 157/111


1B. SOLAR FORECAST
             28 May             29 May             30 May
Activity     R0-R1,chance R2    R0-R1,chance R2    R0-R1,chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   155/109            155/109            145/99

COMMENT: Solar activity on UT day 27-May was at the R0 level. 
The largest region on the solar disk AR3315(S17W03, beta-gamma) 
has increased in size and magnetic complexity but has yet to 
produce a major flare. Whilst this region has increased in magnetic 
complexity, the magnetic gradient currently exhibited in the 
intermediate spot area of this sunspot group is not considered 
as particularly steep/strong. AR3315 produced 3 minor C class 
flares, the largest only a C2.8. However, the region has entered 
a solar longitude range where if a major flare does occur it 
is more likely to be geoeffective. Other solar regions were either 
stable or in slow decay. Solar region AR3314(N12W55, alpha) produced 
the largest flare of the day a C8.4 at 27/0435UT. Solar region 
AR3311(N18W43, beta) produced two minor C2.9 flares. Solar region 
AR3312(S24W35, beta) produced a C6.2 at 27/1924UT. A new small 
spot has emerged at N20E05. Small region AR316(N09E27, beta) 
is showing some growth. Previously flare active solar region 
AR3296 (N15) has not returned to the north east limb. Solar activity 
is expected to be at R0-R1, with a chance of an R2 flare (from 
AR3315) over 28-30 May. No Earth directed CMEs have been observed. 
An eastward non Earth directed CME was observed in LASCO C2 from 
27/1224UT associated with an eruptive prominence on the solar 
east limb. The solar wind speed on UT day 27-May showed a steady 
trend and ranged from 460 to 372 km/s, and is currently near 
420 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 5nT and the north-south IMF component range was +4 to 
-5nT. The solar wind did not decline as much as expected. The 
solar wind speed is still expected to continue to decrease to 
background level levels as coronal hole effects wane. A small 
coronal hole is located just west of the solar meridian at solar 
latitude N40, this hole may then produce a very mild increase 
in solar wind speed in coming days. Another larger coronal hole 
is visible in the southeast solar quadrant. An isolated equatorial 
coronal hole is visible in the eastern solar hemisphere. There 
is a slight chance for a very weak CME transient signature in 
the solar wind parameters on 29-May.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 27 May: G0

Estimated Indices 27 May : A   K           
   Australian Region       1   11000011
      Cocos Island         1   12000000
      Darwin               1   11100101
      Townsville           1   11100011
      Learmonth            1   11000011
      Alice Springs        1   01100001
      Gingin               1   11000011
      Canberra             0   01000001
      Hobart               1   01000111    

Estimated Antarctic Regional K Indices 27 May :
      Macquarie Island     0   00000001
      Casey                6   23220122
      Mawson              19   33211146

Observed Regional daily pc3 Indices 27 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               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 27 May : A 
           Fredericksburg         3
           Planetary              4                         

Observed AFr/Ap Indices 26 May :  A   K
           Fredericksburg         6
           Planetary              6   3211 1122     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
28 May     6    G0
29 May    13    G0, slight chance of G1
30 May    10    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
on UT day 27-May. G0 conditions were mostly observed in the Antarctic 
region with an isolated G1 period at Mawson. G0 geomagnetic conditions 
are expected over 28-30 May. There is a slight chance for a very 
weak glancing blow from a CME on 29-May.

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

PCA Event : No event.

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

COMMENT: HF communication conditions on UT day 27-May were generally 
fair to 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 28-30 May. Isolated 
shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
27 May    74

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.
      Depressed by 30% 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
28 May    90    Near predicted monthly values
29 May    90    Near predicted monthly values
30 May    90    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 27-May were generally slightly depressed to 
near predicted monthly values in the Australian region during 
the local day, with depressions of up to 30% observed during 
local night hours for northern region Australia. Spread-F was 
observed at some sites during local night hours. MUFs are expected 
to be near predicted monthly values over 28-30 May. Isolated 
shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 26 May
       Daily Proton Fluence >1 MeV:   3.4E+04
       Daily Proton Fluence >10 MeV:  2.3E+04
       Daily Electron Fluence >2 MeV: 2.00E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:15%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.4

DSCOVR Satellite Solar Wind Day Averaged Data for 26 May
Speed: 478 km/sec  Density:    0.5 p/cc  Temp:   140000 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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