[Ips-dsgr] ASWFC Daily Report - 19 February 23 issued 2330 UT on 19 Feb 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Mon Feb 20 10:30:54 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 FEBRUARY AND FORECAST FOR 20 FEBRUARY - 22 FEBRUARY
STATUS INDICATORS SOL:** YELLOW **   MAG:** RED **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Feb:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Feb: 169/123


1B. SOLAR FORECAST
             20 Feb             21 Feb             22 Feb
Activity     R1,chance R2       R1,chance R2       R1,chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            150/105            140/94

COMMENT: Solar activity on UT day 19-Feb was at the R0 level. 
Solar region AR3226(N10W36, beta) produced several C flares, 
the largest a C6.8 at 19/0817UT. This region is now showing decline 
in its trailer spots. The region that produced the recent X2 
flare, region AR3229(N23E39, beta), is showing growth in its 
intermediate spots. This region is currently not very magnetically 
complex, exhibiting only a bipolar magnetic pattern and has 
been relatively flare quiet over the past 24 hours, producing 
two minor C class flares. A new region is rotating onto the solar 
disk at solar latitude N25 and appears to be the source of at 
least one of the C class flares observed late in the UT day on 
19-Feb. Solar region AR3225(S21W80, beta) showed slight development 
in its intermediate spots as it rotates off disk. There are currently 
7 solar regions on the disk, a new minor region AR3232 is emerging 
and growing in the solar northwest quadrant. Solar activity is 
expected to be at the R1 level with the chance of an isolated 
R2 level event. Several CMEs were observed on 19-Feb, but none 
are considered geoeffective. A southwest directed CME which was 
in progress early on 19-Feb, appearing to start from mid to late 
18-Feb in LASCO C2 imagery could not be correlated with any on 
disk activity. Later another southwest CME was observed over 
the period 19/11-16UT associated with an erupting solar prominence 
on the western solar limb. A 20 degree long solar filament located 
at N35E05 was active from 19/0930UT in GONG H-alpha imagery partially 
erupting, but no CME appeared to be associated. The solar wind 
speed on UT day 19-Feb showed a declining trend, ranging from 
330 to 417 km/s, and is currently near 318 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 6 nT, and the north-south 
IMF component (Bz) range was +5 to -5 nT. The anticipated increase 
in solar wind speed on 19-Feb did not eventuate. An enhancement 
in the solar wind speed remains expected from mid to late 20-Feb 
due to partial impact from a CME first observed on 17-Feb. The 
ACE EPAM CME precursor channel is currently showing only a slight 
increasing trend late in the UT day 19-Feb, suggesting a possible 
weaker CME arrival. The solar wind speed is expected to be elevated 
over 20-21 Feb due to CME effects, combined with high speed wind 
stream effects from a small equatorial coronal hole now past 
solar central meridian.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 19 Feb: G0

Estimated Indices 19 Feb : A   K           
   Australian Region       6   21113212
      Cocos Island         3   11111111
      Darwin               5   21112212
      Townsville           6   21113222
      Learmonth            5   20113212
      Alice Springs        5   20113212
      Gingin               5   20213112
      Canberra             5   20113112
      Hobart               5   21113211    

Estimated Antarctic Regional K Indices 19 Feb :
      Macquarie Island    10   11115311
      Casey               12   34422112
      Mawson              19   52422334

Observed Regional daily pc3 Indices 19 Feb : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               0   (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 19 Feb : A 
           Fredericksburg         8
           Planetary             12                         

Observed AFr/Ap Indices 18 Feb :  A   K
           Fredericksburg         5
           Planetary              4   1200 2121     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
20 Feb    30    G0-G1, slight chance of an isolated G2 period
21 Feb    18    Initially at G1 then declining to G0
22 Feb    12    G0

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 19-Feb. G0-G1 geomagnetic 
conditions were observed in the Antarctic region. G0-G1 geomagnetic 
conditions are generally expected over the interval 20-21 Feb, 
with the slight chance of an isolated G2 period. Anticipated 
geomagnetic activity on 19-Feb due to an earlier CME has failed to 
eventuate. The anticipated increase in geomagnetic activity over 
20-21 Feb is due to a glancing blow from a CME observed on 17-Feb. 
A high speed solar wind stream from a small equatorial coronal 
hole, may contribute to geomagnetic activity on 21-Feb.

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

PCA Event : No event.

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

COMMENT: HF conditions are expected to be initially near normal, 
becoming fair to poor HF conditions for middle to high latitudes 
from late 20-21 Feb, due to possible increased geomagnetic activity 
from a recent CME. Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
19 Feb   132

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 15-85%.
   Niue Island Region:
      Enhanced by 15%.
   Northern Australian Region:
      Enhanced by 20-50%.
   Southern Australian Region:
      Enhanced by 15-35%.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values 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
20 Feb   120    About 15% above predicted monthly values
21 Feb    95    Near predicted monthly values
22 Feb    95    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 19-Feb were strongly enhanced. Spread F was observed 
at Hobart during local night hours. MUFs are expected to be 15% 
enhanced on 20-Feb. The anticipated increase in geomagnetic activity 
on 19-Feb did not eventuate, and the subsequent mild depressions 
forecast for 20-Feb are now not expected. MUFs are expected to 
be near predicted monthly values on 21-22 Feb, with mild depressions 
possible due to anticipated geomagnetic activity caused the anticipated 
arrival of a CME. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 18 Feb
       Daily Proton Fluence >1 MeV:   2.2E+05
       Daily Proton Fluence >10 MeV:  2.6E+04
       Daily Electron Fluence >2 MeV: 4.60E+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 18 Feb
Speed: 432 km/sec  Density:    5.5 p/cc  Temp:   104000 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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