[Ips-dsgr] ASWFC Daily Report - 29 May 23 issued 2331 UT on 29 May 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Tue May 30 09:31:25 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 MAY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 MAY AND FORECAST FOR 30 MAY - 01 JUNE
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 May:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 29 May: 154/109


1B. SOLAR FORECAST
             30 May             31 May             01 Jun
Activity     R0-R1, chance R2   R0-R1, chance R2   R0-R1, chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   150/105            140/94             135/89

COMMENT: Solar activity on UT day 29-May was at R0 levels. The 
largest flare on the UT day was a double peaked C5.9 flare from 
AR3310(S20W79, alpha) from 1820 UT. There are currently 10 numbered 
sunspot regions on the solar disk. AR3315 (S17W31, beta), which 
featured in yesterday's forecast, has started to decay and has 
not produced any significant flares over the 24 hour period. 
AR3317 (N28W37, beta), AR3318 (N25W30, beta) and AR3319 (S17E02, 
beta) have all shown rapid growth. All other sunspot regions 
are either stable or in decay. Solar activity is expected to 
be at R0-R1 levels over 30-May to 01-Jun, with a chance for R2 
flares. A slow moving northwest CME was observed in SOHO imagery 
from 29/0200 UT, but is likely a farside event and not geoeffective. 
No other CMEs were observed. The solar wind speed was on a general 
declining trend on UT day 29-May and ranged between 357 to 455 
km/s. The peak total interplanetary magnetic field strength (IMF, 
Bt) was 6 nT and the north-south IMF component (Bz) range was 
+5 to -4 nT. A large coronal hole in the southern solar hemisphere 
may increase solar wind speeds by 01-Jun, although given its 
southern latitudinal extent this is low confidence. Otherwise, 
the solar wind speed is expected to remain near background levels 
over 30-May to 01-Jun.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 29 May: G0

Estimated Indices 29 May : A   K           
   Australian Region       1   11100001
      Cocos Island         1   11110000
      Darwin               1   10110011
      Townsville           2   11100012
      Learmonth            1   11100000
      Alice Springs        0   00000001
      Gingin               0   10000000
      Canberra             1   11000001
      Hobart               0   00001000    

Estimated Antarctic Regional K Indices 29 May :
      Macquarie Island     0   00011000
      Casey                5   22221211
      Mawson              10   22210125

Observed Regional daily pc3 Indices 29 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 29 May : A 
           Fredericksburg         7
           Planetary              8                         

Observed AFr/Ap Indices 28 May :  A   K
           Fredericksburg        11
           Planetary             13   3432 3222     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
30 May     6    G0
31 May     6    G0
01 Jun     6    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 30-May. G0 geomagnetic conditions 
are expected over 30-May to 01-Jun.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
29 May      Poor           Normal-fair    Fair-poor      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
30 May      Fair           Normal-fair    Fair
31 May      Normal-fair    Normal-fair    Fair
01 Jun      Normal-fair    Normal-fair    Fair

COMMENT: HF communication conditions on UT day 29-May were generally 
fair. Degraded conditions were observed at low latitude and high 
latitude regions, with mid-latitude regions being generally normal. 
HF communication conditions are expected to be normal to fair 
over 30-May to 01-Jun, with degradations possible during local 
night hours. Isolated shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
29 May    75

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 15% during local day.
      Depressed by 15% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% 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 during local day.
      Depressed by 15% during local night.
   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
30 May    75    Near predicted monthly values to 15-20% depressed
31 May    75    Near predicted monthly values to 15-20% depressed
01 Jun    75    Near predicted monthly values to 15-20% depressed

COMMENT: ASWFC SWF HF Communications Warning 52 was issued on 
28 May and is current for 29-31 May. Maximum usable frequencies 
(MUFs) on UT day 29-May were near predicted monthly values to 
20% depressed during local night hours. Strong spread-F was observed 
in Hobart; sporadic-E was observed at Townsville, Brisbane and 
Cocos Islands, and general degraded conditions were observed 
in Darwin and Brisbane. MUFs are expected to be near predicted 
monthly values over 30-May to 01-Jun, with some mild depressions. 
Isolated shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 28 May
       Daily Proton Fluence >1 MeV:   4.8E+04
       Daily Proton Fluence >10 MeV:  2.4E+04
       Daily Electron Fluence >2 MeV: 2.30E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B8.3

DSCOVR Satellite Solar Wind Day Averaged Data for 28 May
Speed: 442 km/sec  Density:    0.1 p/cc  Temp:    60300 K  Bz:  -4 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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