[Ips-dsgr] ASWFC Daily Report - 27 April 24 issued 2330 UT on 27 Apr 2024 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Apr 28 09:30:46 EST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 APRIL 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 APRIL AND FORECAST FOR 28 APRIL - 30 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Apr: R1
Flares Max Fadeout Freq. Sectors
M2.1 1235UT possible lower European
M3.1 2140UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Apr: 153/108
1B. SOLAR FORECAST
28 Apr 29 Apr 30 Apr
Activity R1 R1 R1
Fadeouts Possible Possible Possible
10.7cm/SSN 140/94 135/89 135/89
COMMENT: Solar activity on UT day 27-Apr was R1 with M2.1 and
M3.1 flares from AR3654(S06W21, beta-gamma). This region has
shown rapid development in the past 24 hours. There are currently
9 solar regions on the visible solar disk. The other solar regions
are relatively small and stable. A 20 degree long solar filament
to the southwest of AR3654 with centre location at S15W25 erupted
over the interval 27/1200-1300UT. Solar activity is expected
to be R1 over 28-30 Apr due to development in AR3654. No Earth
directed CMEs were observed on 27-Apr. The erupting filament
did not appear to be associated with a CME. S0 solar radiation
storm conditions were observed on 27-Apr. S0 solar radiation
storm conditions are expected over 28-30 Apr. The solar wind
speed on UT day 27-Apr ranged between 312 to 530 km/s, with the
peak in wind speed observed near the middle of the UT day and
is currently near 430 km/sec. The peak total interplanetary field
strength (IMF, Bt) was 17 nT and the north-south IMF component
range (Bz) was +14 to -10 nT. The solar wind speed is currently
elevated due to a coronal hole wind stream and is expected to
be mildly enhanced on 28-Apr. Another isolated coronal hole is
visible in the solar southwest quadrant centered at S35W35. This
coronal hole may cause a mild increase in solar wind speed from
29-Apr to 01-May, though its more southern latitude location
may reduce effects. A long thin coronal hole is just crossing
the solar central meridian in the northern solar hemisphere extending
in solar latitude from N50 to S10. This hole is expected to increase
the solar wind speed from late 01-02 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Apr: G0
Estimated Indices 27 Apr : A K
Australian Region 6 22212122
Cocos Island 5 22212111
Darwin 5 22212112
Townsville 8 22222223
Learmonth 7 32222122
Alice Springs 6 22212122
Gingin 7 32212122
Canberra 7 22213122
Kennaook Cape Grim 7 21213222
Hobart 7 22213222
Estimated Antarctic Regional K Indices 27 Apr :
Macquarie Island 8 22214212
Casey 12 34332222
Mawson 16 54223123
Observed Regional daily pc3 Indices 27 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (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 Apr : A
Fredericksburg 13
Planetary 18
Observed AFr/Ap Indices 26 Apr : A K
Fredericksburg 11
Planetary 17 1243 3532
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Apr 12 G0, slight chance G1
29 Apr 10 G0
30 Apr 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 27-Apr. In the Antarctic region an isolated
period of G1 was observed at Mawson, with G0 conditions at Macquarie
Island and Casey. G0 geomagnetic conditions are generally expected
over 28-30 Apr, with a slight chance for G1 conditions on 28-Apr
in association with a coronal hole high speed wind streams. There
is also a slight possibility that components of recent CMEs may
arrive at the Earth, although this is not expected to induce
significant activity. Another coronal hole may induce a mild
increase in geomagnetic activity on 02-May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Apr Fair-normal Normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Apr Normal Normal Fair-normal
29 Apr Normal Normal Fair-normal
30 Apr Normal Normal Normal
COMMENT: HF radio communication conditions were generally fair
to normal on 27-Apr, with equatorial ionospheric scintillation
observed during local night hours. HF radio communication conditions
are expected to be mostly normal over 28-30 Apr, with ongoing
mildly degraded conditions at high latitudes. Isolated shortwave
fadeouts are expected.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Apr 134
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 60% during local night.
Enhanced by 30% after local dawn.
Niue Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values to 15% enhanced.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Mar 120
Apr 114
May 115
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
28 Apr 140 About 15% above predicted monthly values
29 Apr 140 About 15% above predicted monthly values
30 Apr 140 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 42 was issued on
27 April and is current for 28-30 Apr. Maximum usable frequencies
(MUFs) in the Australian region were near predicted monthly values
to 15% enhanced on UT day 27-Apr. Strong enhancements were observed
at Cocos Island during local night hours. Spread F was observed
at Hobart during local night hours. Ionospheric scintillation
was observed 27/1301-1430UT at Darwin and Weipa. MUFs are expected
to be near predicted values over to 15% enhanced during the interval
28-30 Apr. Isolated shortwave fadeouts are expected.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Apr
Daily Proton Fluence >1 MeV: 2.1E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 3.50E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C2.0
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Apr
Speed: 333 km/sec Density: 2.3 p/cc Temp: 42400 K Bz: -6 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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