[Ips-dsgr] ASWFC Daily Report - 25 May 23 issued 2331 UT on 25 May 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Fri May 26 09:31:05 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 MAY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 MAY AND FORECAST FOR 26 MAY - 28 MAY
STATUS INDICATORS SOL:** RED ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 May: R1
Flares Max Fadeout Freq. Sectors
M1.1 1446UT possible lower South American/
Atlantic
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 R2
Fadeouts Probable Probable Probable
10.7cm/SSN 150/105 155/109 155/109
COMMENT: Solar activity on UT day 25-May reached R1 levels, with
the largest flare being M1.1 at 1448 UT from AR3312 (S24W11,
gamma). There are currently 6 numbered sunspot regions on the
solar disk. AR3310 (S20W28, gamma) has shown decay in its trailer
spots, but also is showing decay from the center of its largest
spot. AR3311 (N18W21, beta-gamma), which has produced numerous
M-class flares recently, has started decaying and its delta configuration
has weakened. AR3314 (N12W30, beta-gamma) and AR3315 (S17E28,
beta) have both shown growth over the 24 hour period, and all
other sunspot regions are stable. Solar activity is expected
to be at R1, with a chance of R2 over 26-28 May. A southwest
CME was observed in SOHO imagery from 25/0800, but analysis indicates
it is a farside event that will not impact Earth. A small CME
was observed from the southwest quadrant from 25/1448 UT, associated
with the M1.1 flare from AR3312. There is a chance of a weak
glancing blow on 29-May, but confidence is low. A CME to the
east was observed from 25/2148 UT, however a preliminary analysis
suggests it will not be Earth directed. Not other CMEs were observed.
The solar wind speed on UT day 25-May was on a steady trend and
ranged from 450 to 666 km/s, and is currently near 550 km/s.
The peak total interplanetary field strength (IMF, Bt) was 6
nT and the north-south IMF component range was +4 to - 6nT. The
solar wind speed is expected to begin to decrease to background
levels over 26-28 May as coronal hole wind stream effects wane.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 May: G0
Estimated Indices 25 May : A K
Australian Region 6 22322120
Cocos Island 3 11221020
Darwin 6 21322121
Townsville 7 22322121
Learmonth 9 22333130
Alice Springs 6 22322120
Gingin 8 22232230
Canberra 5 21222120
Hobart 6 21232121
Estimated Antarctic Regional K Indices 25 May :
Macquarie Island 19 32364121
Casey 13 33333232
Mawson 28 44443263
Observed Regional daily pc3 Indices 25 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 11 (Quiet)
Hobart 6 (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 12
Planetary 12
Observed AFr/Ap Indices 24 May : A K
Fredericksburg 10
Planetary 10 2311 3333
2B. MAGNETIC FORECAST
Date Ap Conditions
26 May 10 G0
27 May 8 G0
28 May 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 25-May. Mostly G0 geomagnetic conditions were
observed in the Antarctic region, with an isolated period of
G2 at Mawson and at Macquarie Island. G0 geomagnetic conditions
are expected over 26-28 May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 May Fair Normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 May Normal-fair Normal Normal-fair
27 May Normal Normal Normal-fair
28 May Normal Normal Normal
COMMENT: HF communication conditions on UT day 25-May were generally
normal, with some mild degradations observed in low nad high
latitudes. Mid latitude region conditions were generally good.
HF communication conditions are expected to be mostly normal
over 26-28 May, with a chance for mildly degraded conditions
in high latitude regions at local night hours. Shortwave fadeouts
are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 May 91
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 35% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 15% 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
26 May 100 Near predicted monthly values
27 May 110 Near predicted monthly values tp 10-15% enhanced
28 May 115 Near predicted monthly values to 15-20% enhanced
COMMENT: ASWFC SWF HF Communications Warning 50 was issued on
25 May and is current for 26-28 May. Maximum usable frequencies
(MUFs) on UT day 25-May were near predicted monthly values in
the Australian region. Spread-F was observed in Townsville, Brisbane
and Hobart during local night hours. MUFs are expected to be
near predicted monthly values over 26-28 May, with enhancements
of 15-20% possible later in the period. Shortwave fadeouts are
possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 May
Daily Proton Fluence >1 MeV: 3.9E+04
Daily Proton Fluence >10 MeV: 2.3E+04
Daily Electron Fluence >2 MeV: 1.20E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 24 May
Speed: 557 km/sec Density: 1.6 p/cc Temp: 152000 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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