SIDC ursigram

3-day-forecast of solar and geomagnetic activity.
Source SIDC (RWC-Belgium)
Frequency Daily
Format Encoded data (ISES)
Mail header SIDC ursigram
SIDC code tot

Latest issue

:Issued: 2021 Apr 18 1230 UTC
:Product: documentation at http://www.sidc.be/products/tot
#--------------------------------------------------------------------#
# DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC     #
#--------------------------------------------------------------------#
SIDC URSIGRAM 10418
SIDC SOLAR BULLETIN 18 Apr 2021, 1230UT
SIDC FORECAST (valid from 1230UT, 18 Apr 2021 until 20 Apr 2021)
SOLAR FLARES  : Quiet conditions (<50% probability of C-class flares)
GEOMAGNETISM  : Active conditions expected (A>=20 or K=4)
SOLAR PROTONS : Quiet
PREDICTIONS FOR 18 Apr 2021  10CM FLUX: 076 / AP: 016
PREDICTIONS FOR 19 Apr 2021  10CM FLUX: 075 / AP: 013
PREDICTIONS FOR 20 Apr 2021  10CM FLUX: 076 / AP: 005
COMMENT: Solar activity remained at very low levels over the last 24 hours.
The visible active regions NOAA 2814 (Catania 86, magnetic type Beta), NOAA
2815 (not classified) and NOAA 2016 (magnetic type Beta) remained at very
low levels of activity. A B9.7 class-flare (peak time 17:17 UTC) was
produced on April 17th by an active region behind the east limb and
resulted in a type II radio emission. The flaring activity within the next
24 hours is expected at very low to low levels with 40% chance for a
C-class flare.

A CME associated with the B9.7 class-flare was detected to leave the east
limb around 16:36 UTC on April 17th. It will not impact the Earth. No other
Earth-directed coronal mass ejections (CMEs) were detected in the available
coronagraph imagery at the moment.

The greater than 10 MeV proton flux was at nominal levels in the past 24
hours and is expected to remain so in the next 24 hours. The greater than
2MeV electron flux crossed the 1000 pfu threshold several times and is
expected to remain above the threshold for long periods throughout April
18th. The 24h electron fluence reached moderate levels and is expected to
remain at moderate levels in the next 24 hours.

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) remained
elevated from the high speed stream (HSS) currently affecting the Earth.
The total magnetic field registered a maximum magnitude of 10 nT with a
minimum Bz of -10 nT. The solar wind speed varied between 570 km/s and 670
km/s. The solar wind speed is expected to remain elevated throughout April
18th.

Unsettled to active geomagnetic conditions were registered over the past 24
hours under the influence of the HSS. Unsettled to active geomagnetic
conditions are expected for the next 24 hours. Isolated periods of minor
geomagnetic storms remain possible in case of prolonged intervals with
negative Bz.
TODAY'S ESTIMATED ISN  : 016, BASED ON 17 STATIONS.
99999

SOLAR INDICES FOR 17 Apr 2021
WOLF NUMBER CATANIA    : ///
10CM SOLAR FLUX        : 075
AK CHAMBON LA FORET    : 031
AK WINGST              : 031
ESTIMATED AP           : 033
ESTIMATED ISN          : 018, BASED ON 29 STATIONS.

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
NONE
END

UMAGF 30503 10418 1004/ 17066 1/031 23344 33332
UMAGF 31523 10418 0000/ 17004 1/031 25443 34544
BT
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Details

The SIDC ursigram starts with the code SIDC URSIGRAM YMMDD, where
Y is the last digit of the year number,
MM is the number of the month,
DD is the day of the month.
Besides the ISES codes like UMAGF, UCOSE and USSPS,
this message contains a forecast on:
the global flare probability,
geomagnetic disturbances,
solar proton events.
PREDICTIONS FOR "today" : 10CM FLUX: xxx / AP: xxx
PREDICTIONS FOR "today+1": 10CM FLUX: xxx / AP: xxx
PREDICTIONS FOR "today+2": 10CM FLUX: xxx / AP: xxx
COMMENT
ESTIMATED ISN : xxx, based on xx stations.
where ISN stands for International Sunspot Number.

OBSERVED SOLAR INDICES FOR THE DAY BEFORE
SUNSPOT INDEX : xxx, the Wolf number observed by Catania
10CM SOLAR FLUX : xxx,
AK CHAMBON LA FORET : xxx,
AK WINGST : xxx,
ESTIMATED AP : xxx,
ESTIMATED ISN : xxx, based on xx stations.

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX END LOC XRAY OP 10CM TYPE Catania NOAA NOTE

DAY gives the day-of-the-month.
BEGIN, MAX and END give the UT time of the different phases of the X-ray output of the event.
LOC gives the location of the event in heliographic coordinates.
XRAY gives the GOES X-ray class of the event.
OP lists the optical flare class.
10cm gives the 10.7 cm radioflux output of the event.
TYPE specifies the type of radiobursts observed.
Catania gives the Catania sunspot group number where the event happened.
NOAA is the corresponding NOAA active region number.
NOTE is the header of any other type of information, e.g. if a CME was observed associated with the event.


Check the ISES code book for information on ISES codes.