[Ips-dsgr] ASWFC Daily Report - 17 February 26 issued 2330 UT on 17 Feb 2026 [SEC=OFFICIAL]

Wed Feb 18 10:30:43 AEDT 2026

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 FEBRUARY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 FEBRUARY AND FORECAST FOR 18 FEBRUARY - 20 FEBRUARY
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Feb:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Feb: 122/75

1B. SOLAR FORECAST
             18 Feb             19 Feb             20 Feb
Activity     R0, chance of R1   R0, chance of R1   R0, chance of R1
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   125/78             125/78             125/78

COMMENT: Solar flare activity on UT day 17-Feb was at the R0 
level, with no significant flaring activity. There are currently 
five numbered sunspot regions visible on the solar disk. AR4374 
(N09W34, beta) is the most magnetically complex region on the 
disk and has shown recent decay in its trailer spots. AR4377 
(N08E26, alpha) has exhibited mild spot growth. AR4373 (N10W77, 
alpha) is stable and will soon rotate over the western limb. 
All other sunspot regions are either stable or in decay. Solar 
flare activity is expected to be at the R0 level over 18-20 Feb, 
with a chance of R1. S0 solar proton conditions were observed 
on UT day 17-Feb. S0 solar proton conditions are expected over 
18-20 Feb. No Earth-directed coronal mass ejections (CMEs) have 
been observed. The solar wind speed on UT day 17-Feb decreased, 
ranging from 520 to 705 km/s and is currently near 535 km/s. 
The peak total interplanetary magnetic field strength (IMF, Bt) 
was 7 nT and the north-south IMF component (Bz) range was -5 
to +6 nT. The solar wind speed is expected to decline over 18-20 
Feb due to waning coronal hole effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 17 Feb: G0

Estimated Indices 17 Feb : A   K           
   Australian Region       8   22233212
      Cocos Island         6   22132211
      Darwin               8   22133212
      Townsville           8   22133222
      Learmonth           12   32243312
      Alice Springs        8   22133212
      Gingin              12   32243322
      Canberra             8   22233212
      Kennaook Cape Grim   8   22233212
      Hobart               8   22233212    

Estimated Antarctic Regional K Indices 17 Feb :
      Macquarie Island    20   22455312
      Casey               26   46533322
      Mawson              37   43433357

Observed Regional daily pc3 Indices 17 Feb : 
      Darwin               3   (Quiet)
      Townsville          NA
      Learmonth            2   (Quiet)
      Alice Springs        2   (Quiet)
      Gingin              37   (Quiet to unsettled)
      Canberra            68   (Active)
      Hobart              68   (Active)

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 17 Feb : A 
           Fredericksburg         9
           Planetary             11                         

Observed AFr/Ap Indices 16 Feb :  A   K
           Fredericksburg        23
           Planetary             29   4443 2463     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
18 Feb    16    G0, chance of G1
19 Feb    10    G0
20 Feb     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 17-Feb. Mostly G1 geomagnetic conditions were 
observed in the Antarctic region, with isolated periods of G2 
observed at Casey and Mawson. G0 planetary geomagnetic conditions 
are expected over 18-20 Feb, with a chance of G1 on 18-Feb due 
to a weak CME arrival from a filament eruption first observed 
on 16-Feb.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
18 Feb      Normal         Normal-fair    Fair
19 Feb      Normal         Normal         Normal-fair
20 Feb      Normal         Normal         Normal-fair

COMMENT: Global ionospheric conditions were mostly normal on 
UT day 17-Feb, with fair conditions observed at middle and high 
latitudes. Normal to fair HF conditions are expected over 18-20 
Feb.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
17 Feb    94

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 35% during local day.
      Enhanced by 45% during local night.
   Niue Island Region:
      Enhanced by 15% during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
      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
Jan      96
Feb      88
Mar      87

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
18 Feb    95    Near predicted monthly values
19 Feb    95    Near predicted monthly values
20 Feb    95    Near predicted monthly values

COMMENT: Maximum Usable Frequencies (MUFs) on UT day 17-Feb in 
southern Australian regions were near predicted monthly values 
to 15-20% depressed. MUFs in northern Australia were near predicted 
monthly values to 30% enhanced during local night hours. Spread 
F was observed at Hobart and Canberra during local night hours. 
MUFs are expected to be near predicted monthly values over 18-20 
Feb.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 16 Feb
       Daily Proton Fluence >1 MeV:   5.5E+06
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 4.40E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B4.4

DSCOVR Satellite Solar Wind Day Averaged Data for 16 Feb
Speed: 628 km/sec  Density:    1.8 p/cc  Temp:   248000 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