Viewing archive of Saturday, 16 December 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Dec 16 1230 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
16 Dec 2017	072	015
17 Dec 2017	072	019
18 Dec 2017	072	007

Bulletin

The Sun produced no C flares in the past 24 hours. The chance for a C flare in the next 24 hours is estimated at 5%. A filament eruption near 25S 40E was observed in GONG H-alpha and SDO/AIA 304 A images around 12h UT on December 15. An associated CME was detected by CACTUS in LASCO C2 images at 12:12 UT, with an estimated low speed of 284 km/s using COR2 A J-maps. This CME may arrive at Earth (probability: 20%), in which case it should arrive early on December 20 according to the drag based model. The greater than 10 MeV proton flux was at nominal levels. Solar wind speed measured by DSCOVR suddenly increased from about 345 to 370 km/s around 21:30 UT on December 15. Afterwards, it gradually decreased to current values around 340 km/s. The Interplanetary Magnetic Field (IMF) was mainly directed away from the Sun and its magnitude ranged between about 0.5 and 7 nT. Bz was never below -5 nT. Quiet geomagnetic conditions (K Dourbes between 0 and 2; NOAA Kp between 0 and 2) were registered in the past 24 hours. Active conditions (K Dourbes = 4) are possible on December 16 and 17, with a slight chance for minor geomagnetic storm intervals (K Dourbes = 5), due to the expected arrival of a high speed stream from a recurrent positive equatorial coronal hole. Quiet to unsettled conditions (K Dourbes < 4) are expected on December 18.

Today's estimated international sunspot number (ISN): 000, based on 16 stations.

Solar indices for 15 Dec 2017

Wolf number Catania	000
10cm solar flux	072
AK Chambon La Forêt	006
AK Wingst	003
Estimated Ap	003
Estimated international sunspot number	000 - Based on 17 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

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