[Ips-dsgr] ASWFC Daily Report - 18 February 26 issued 2330 UT on 18 Feb 2026 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Thu Feb 19 10:30:49 AEDT 2026


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 FEBRUARY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 FEBRUARY AND FORECAST FOR 19 FEBRUARY - 21 FEBRUARY
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 18 Feb:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Feb: 119/71


1B. SOLAR FORECAST
             19 Feb             20 Feb             21 Feb
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   120/72             120/72             115/66

COMMENT: Solar flare activity on UT day 18-Feb was at the R0 
level, with the largest flare a C2.2 flare at 18/2042UT. There 
are currently three numbered sunspot regions visible on the solar 
disk. All sunspot regions are small, magnetically simple and 
either stable or in decay. Solar flare activity is expected to 
be at the R0 level over 19-21 Feb. S0 solar radiation storm conditions 
were observed on UT day 18-Feb. S0 solar radiation storm conditions 
are expected over 19-21 Feb. No Earth-directed coronal mass ejections 
(CMEs) have been observed. A large, southwest directed CME is 
visible in SOHO and STEREO-A imagery from 18/0448UT. Associated 
with coronal movement over the southwest limb at around S28, 
visible in SDO, GOES SUVI and H-Alpha imagery from 18/0419UT. 
This CME is considered a far side event and not geoeffective. 
The solar wind speed on UT day 18-Feb decreased, mostly ranging 
between 570 and 430 km/s and is currently near 455 km/s. The 
peak total interplanetary magnetic field strength (IMF, Bt) was 
7 nT and the north-south IMF component (Bz) range was -4 to +5 
nT. The solar wind speed is expected to continue to decline towards 
background levels and remain there over 19-21 Feb.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 18 Feb: G0

Estimated Indices 18 Feb : A   K           
   Australian Region       6   22122221
      Cocos Island         4   12211220
      Darwin               6   22122222
      Townsville           6   12222222
      Learmonth            7   23122222
      Alice Springs        6   22122221
      Gingin               7   22123221
      Canberra             4   12122111
      Kennaook Cape Grim   6   22222211
      Hobart               5   22222111    

Estimated Antarctic Regional K Indices 18 Feb :
      Macquarie Island    10   23134310
      Casey               19   35532222
      Mawson              22   44433352

Observed Regional daily pc3 Indices 18 Feb : 
      Darwin               0   (Quiet)
      Townsville          NA
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              22   (Quiet to unsettled)
      Canberra            31   (Quiet to unsettled)
      Hobart              53   (Unsettled)

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 18 Feb : A 
           Fredericksburg        10
           Planetary             13                         

Observed AFr/Ap Indices 17 Feb :  A   K
           Fredericksburg         7
           Planetary             11   3223 2323     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Feb     9    G0
20 Feb     8    G0
21 Feb     5    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 18-Feb. Mostly G1 geomagnetic conditions were 
observed in the Antarctic region. G0 planetary geomagnetic conditions 
are expected over 19-21 Feb.

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

PCA Event : No event.

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

COMMENT: Global ionospheric conditions were mostly normal on 
UT day 18-Feb, with fair conditions observed at middle and high 
latitudes in the first half of the UT day. Mostly normal HF conditions 
are expected over 19-21 Feb.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
18 Feb    87

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Niue Island Region:
      Enhanced by 35% during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   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
19 Feb    95    Near predicted monthly values
20 Feb    95    Near predicted monthly values
21 Feb    95    Near predicted monthly values

COMMENT: Maximum Usable Frequencies (MUFs) on UT day 18-Feb in 
the Australian region were near predicted monthly values with 
moderate depressions observed during local day in the southern 
Australian region and moderate enhancements observed during local 
night in the northern Australian region. Spread F and sporadic 
E were observed at Hobart during local night hours. MUFs are 
expected to be near predicted monthly values over 19-21 Feb.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 17 Feb
       Daily Proton Fluence >1 MeV:   1.9E+06
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 8.00E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 9%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B3.9

DSCOVR Satellite Solar Wind Day Averaged Data for 17 Feb
Speed: 579 km/sec  Density:    1.5 p/cc  Temp:   152000 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



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