[Ips-dsgr] ASWFC Daily Report - 18 February 23 issued 2331 UT on 18 Feb 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sun Feb 19 10:31:05 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 FEBRUARY AND FORECAST FOR 19 FEBRUARY - 21 FEBRUARY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     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: 167/121


1B. SOLAR FORECAST
             19 Feb             20 Feb             21 Feb
Activity     R0-R1 chance R2-R3 R0-R1 chance R2-R3 R0-R1 chance R2-R3
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            150/105            140/94

COMMENT: Solar activity on UT day 18-Feb was at the R0 level, 
with two C7 flares the largest flares of the day, both produced 
by AR3226 (N10W29, beta). There are currently six numbered sunspot 
regions visible on the solar disk and one unnumbered region. 
AR3225 (S21W73, beta) showed spot development over the UT day 
and both AR3226 and AR3229 (N27E46, beta) showed development 
of their trailer spots. AR3226 and AR3229 are the largest and 
most significant sunspot regions on the solar disk, both have 
a history of M-class flaring and AR3229 produced an X2.2 flare 
on 17-Feb. There is one unnumbered region at N25W23, which exhibited 
spot development over the UT day, but is small and magnetically 
simple. Solar activity is expected to be at R0-R1 levels, with 
a chance of R2-R3 flaring over 19-21 Feb. Several CMEs were observed 
on 18-Feb, but none are considered geoeffective. A southeast 
directed partial halo CME is visible in LASCO C2 imagery from 
18/0248UT. GOES SUVI imagery shows coronal loop expansion behind 
the east limb from 18/0209UT indicating that this is a far side 
event. The solar wind speed on UT day 18-Feb was steady, ranging 
from 405 to 490 km/s, and is currently near 420 km/s. The peak 
total interplanetary field strength (IMF, Bt) was 5 nT, and the 
north-south IMF component (Bz) range was +5 to -5 nT. An increase 
in the solar wind speed is expected on 19-Feb due to an anticipated 
impact from a CME first observed on 15-Feb. This CME was originally 
forecast to impact on 18-Feb. A further enhancement in the solar 
wind speed is expected late on 19-Feb due to an impact from a 
CME first observed on 17-Feb. The solar wind speed is expected 
to be elevated over 20-21 Feb due to ongoing CME effects, combined 
with high speed wind stream effects from an equatorial coronal 
hole currently rotating towards a geoeffective position.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 18 Feb: G0

Estimated Indices 18 Feb : A   K           
   Australian Region       3   11112011
      Cocos Island         2   11111010
      Darwin               3   11111012
      Townsville           3   11112012
      Learmonth            4   21112021
      Alice Springs        3   11112012
      Gingin               4   11113011
      Canberra             3   01112021
      Hobart               5   11213121    

Estimated Antarctic Regional K Indices 18 Feb :
      Macquarie Island     5   12103211
      Casey               16   35432122
      Mawson               9   23223131

Observed Regional daily pc3 Indices 18 Feb : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             2   (Quiet)
      Hobart               4   (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 18 Feb : A 
           Fredericksburg         8
           Planetary             11                         

Observed AFr/Ap Indices 17 Feb :  A   K
           Fredericksburg         4
           Planetary              5   1211 1211     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Feb    20    G0-G1, chance of G2
20 Feb    30    G0-G1, chance of G2
21 Feb    15    G0, chance of G1

COMMENT: ASWFC Geomagnetic Warning 6 was issued on 17 February 
and is current for 18-20 Feb. G0 geomagnetic conditions were 
observed in the Australian region on UT day 18-Feb. G0 geomagnetic 
conditions were observed in the Antarctic region, with the exception 
of an isolated period of G1 at Casey. G0-G1 geomagnetic conditions 
are expected on 19-20 Feb, with a chance of G2. G0 geomagnetic 
conditions, with a chance of G1 are expected on 21-Feb. The expected 
elevated geomagnetic conditions are due to anticipated impacts 
from two CMEs one first observed on 15-Feb and another first 
observed on 17-Feb, both expected to impact on 19-Feb, combined 
with high speed wind stream effects from a small equatorial coronal 
hole, expected to be in a geoeffective position by 21-Feb.

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

PCA Event : No event.

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

COMMENT: Mostly normal HF propagation conditions are expected 
on 19-Feb. Fair to poor HF conditions are expected on 20-Feb, 
particularly at higher latitudes, due to increased geomagnetic 
activity from two anticipated CME impacts. Normal conditions 
are expected on 21-Feb, with a chance of degradations due to 
ongoing increased geomagnetic activity. Shortwave fadeouts are 
possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
18 Feb   112

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 35% during local night.
      Enhanced by 35% after local dawn.
   Niue Island Region:
      Enhanced by 25% during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
      Enhanced by 30% after local dawn.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Enhanced by 15% over the UT day.

Monthly T index:
Month  T index
Jan      119
Feb      75
Mar      76

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
19 Feb   120    Near to 15% above predicted monthly values
20 Feb    80    Near predicted monthly values
21 Feb    80    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 18 was issued on 
17 February and is current for 18-20 Feb. ASWFC Preliminary HF 
Communications Warning 19 was issued on 17 February and is current 
for 19-21 Feb. Maximum usable frequencies (MUFs) in the Australian 
region on 18-Feb were near predicted monthly values during local 
day and up to 20% enhanced during local night. Spread F was observed 
at Hobart and Canberra. MUFs are expected to be near predicted 
monthly values to 15% enhanced on 19-Feb. MUFs are expected to 
be near predicted monthly values on 20-21 Feb, with mild depressions 
possible due to anticipated geomagnetic activity caused by CME 
impacts. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 17 Feb
       Daily Proton Fluence >1 MeV:   4.3E+05
       Daily Proton Fluence >10 MeV:  2.5E+04
       Daily Electron Fluence >2 MeV: 2.70E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.5

DSCOVR Satellite Solar Wind Day Averaged Data for 17 Feb
Speed: 489 km/sec  Density:    7.0 p/cc  Temp:   251000 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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