[Ips-dsgr] ASWFC Daily Report - 15 May 26 issued 2330 UT on 15 May 2026 [SEC=OFFICIAL]

Sat May 16 09:30:54 AEST 2026

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/15 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 15 MAY AND FORECAST FOR 16 MAY - 18 MAY
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 15 May:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 15 May: 101/49

1B. SOLAR FORECAST
             16 May             17 May             18 May
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   100/48             100/48             100/48

COMMENT: Solar flare activity on UT day 15-May was at the R0 
level, the largest flare of the day was a C9.5 flare observed 
at 15/1614UT. There are currently three numbered sunspot regions 
visible on the solar disk. AR4438 (N19W54, beta) showed spot 
separation over the UT day. AR4435 (N23W78, beta) was stable 
and produced the largest flare of the UT day. No large or significantly 
magnetically complex regions exist on the solar disk. Solar flare 
activity is expected to be at the R0 level over 16-18 May, with 
a chance of R1. S0 solar proton conditions were observed on UT 
day 15-May. S0 solar proton conditions are expected over 16-18 
May. No Earth-directed CMEs have been observed on 15-May. A north 
directed CME is visible in SOHO and STEREO-A imagery from 15/0418UT, 
associated with a filament eruption at around N20E05 from 15/0250UT 
visible in SDO, GOES SUVI and H-Alpha imagery. This CME is expected 
to pass above the Earth. The solar wind speed on UT day 15-May 
increased due to coronal hole high speed wind stream effects, 
ranging from 385 to 750 km/s and is currently near 640 km/s. 
The peak total interplanetary magnetic field strength (IMF, Bt) 
was 17 nT and the north-south IMF component (Bz) range was -14 
to +10 nT. The solar wind speed is expected to remain elevated 
over 16-18 May due to ongoing coronal hole high speed wind stream 
effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 15 May: G1

Estimated Indices 15 May : A   K           
   Australian Region      19   22225335
      Cocos Island        13   22323334
      Darwin              18   22334335
      Townsville          21   22335335
      Learmonth           22   22335345
      Alice Springs       19   12235335
      Gingin              17   12224435
      Canberra            18   11225335
      Kennaook Cape Grim  18   21225335
      Hobart              18   21225335    

Estimated Antarctic Regional K Indices 15 May :
      Macquarie Island    34   11246645
      Casey               26   23333356
      Mawson              61   43445468

Observed Regional daily pc3 Indices 15 May : 
      Darwin               9   (Quiet)
      Townsville           3   (Quiet)
      Learmonth            2   (Quiet)
      Alice Springs        4   (Quiet)
      Gingin              39   (Quiet to unsettled)
      Canberra            48   (Unsettled)
      Hobart             111   (Major storm)

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 15 May : A 
           Fredericksburg        22
           Planetary             36                         

Observed AFr/Ap Indices 14 May :  A   K
           Fredericksburg         5
           Planetary              5   3221 1111     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
16 May    20    G0-G1
17 May    16    G0, chance of G1
18 May    12    G0

COMMENT: ASWFC Geomagnetic Warning 32 was issued on 15 May and 
is current for 15-16 May. G1 geomagnetic conditions were observed 
at both the planetary level and in the Australian region on 15-May. 
Mostly G2 conditions were observed in the Antarctic region, with 
a period of G4 observed at Mawson. G0-G1 geomagnetic conditions 
are expected on 16-May and G0 geomagnetic conditions, with a 
chance of G1 are expected on 17-May due to ongoing coronal hole 
high speed wind stream effects. G0 conditions are expected on 
18-May.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
15 May      Normal         Normal         Normal-fair    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
16 May      Normal         Normal-fair    Fair
17 May      Normal         Normal-fair    Fair
18 May      Normal         Normal         Normal-fair

COMMENT: Global ionospheric conditions were mostly normal over 
UT day 15-May, with some degraded conditions observed at high 
latitudes in the northern hemisphere. Mostly normal conditions 
are expected over 16-18 May, with the chance of mild degradations 
on 16 May at higher latitudes.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
15 May    47

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Depressed by 15% during local day.
      Depressed by 15% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Apr      74
May      71
Jun      68

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
16 May    55    Near predicted monthly values/depressed 5 to 
                15%
17 May    60    Near predicted monthly values
18 May    65    Near predicted monthly values

COMMENT: ASWFC HF Communications Warning 48 was issued on 13 
May and is current for 14-16 May. Maximum Usable Frequencies 
(MUFs) were depressed by 15% in the northern Australian region, 
with frequencies mostly near predicted monthly vales in the southern 
region. Spread-F was observed at Hobart during local night hours. 
MUFs are expected to be near predicted monthly values over 16-18 
May, with depressions of up to 15% expected in the first half 
of the day of 16-May in the southern Australian region.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 14 May
       Daily Proton Fluence >1 MeV:   5.0E+05
       Daily Proton Fluence >10 MeV:  1.9E+04
       Daily Electron Fluence >2 MeV: 1.20E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.0

DSCOVR Satellite Solar Wind Day Averaged Data for 14 May
Speed: 417 km/sec  Density:    4.7 p/cc  Temp:    71700 K  Bz:   1 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