Viewing archive of Monday, 17 July 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Jul 17 1239 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

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

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
17 Jul 2017	085	026
18 Jul 2017	083	015
19 Jul 2017	083	007

Bulletin

NOAA active region 2665 (Catania group 36) continued to produce B flares and a couple of C flares. The strongest was a C2.3 flare peaking at 3:28UT. As it is rotating towards the West limb the trailing spots have disappeared from this region but especially the intermediate section of the region appears to remain fairly dynamic. Further C class flares are expected and there remains a potential for an M flare from this region until it has well passed the West limb. No Earth directed CMEs have been observed in coronagraph data. Proton flux levels remained at background values. Strong activity from region 2665 could possibly lead to an increase in proton flux levels in the next few days until the region has well passed the West limb.

Solar wind was marked by the passage of the July 14 CME. After the shock arrival observed in the past reporting period, during this period total magnetic field declined from 21nT at noon July 16 to around 10nT around midnight when also density dropped back to background values. Solar wind speed reached a maximum of over 600 km/s around 21:00UT before declining to under 500km/s currently. The Northward component of the magnetic field remained strongly negative (down to -15nT) until midnight before settling at near zero values on July 17. Over the next 24 hours we expect a recovery towards nominal solar wind conditions with elevated values for magnetic field and Solar wind speed slowly decaying. Geomagnetic conditions reached minor to moderate storm levels (local K Dourbes 5 and NOAA Kp 6) in the afternoon of July 16 due to the persistent strongly negative values of Bz. Since midnight quiet to active conditions (local K Dourbes 2-4, NOAA Kp 3-4) have been recorded. Dst reached a minimum of -69nT at 15:00UT. Over the next 24 hours active periods remain possible due to the elevated Solar wind speed and strong magnetic field. Afterwards quiet to unsettled conditions are expected.

Today's estimated international sunspot number (ISN): 022, based on 20 stations.

Solar indices for 16 Jul 2017

Wolf number Catania	///
10cm solar flux	087
AK Chambon La Forêt	056
AK Wingst	043
Estimated Ap	043
Estimated international sunspot number	021 - Based on 28 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page