Viewing archive of Tuesday, 19 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 19 1231 UTC

SIDC Forecast

Valid from 1230 UTC, 19 Sep 2017 until 21 Sep 2017
Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

10cm fluxAp
19 Sep 2017072005
20 Sep 2017073006
21 Sep 2017076006

Bulletin

Over the past 24 hours the solar activity was very low with no flaring activity recorded. The Catania sunspot group 55 (NOAA active region 2680) is the only present region on the disc, and is unlikely to produce any flaring activity. We expect the solar activity to remain quiet until the returning region (Catania sunspot group 49 / NOAA active region 2676) will come from behind the East solar limb by the end of the day.

No Earth directed CMEs have been observed and the solar protons remained at background level in the past 24 hours.

Solar wind speed starts a slow overall decline from about 700 km/s to 500 km/s. The interplanetary magnetic field magnitude returned to its nominal 3-6 nT range with the Bz component fluctuating between -4 and 4 nT. The solar wind is expected to further recover to nominal conditions over the next days.

Geomagnetic conditions were quiet to active (local K Dourbes 1-4, NOAA Kp 1-3) and are expected to remain quiet to unsettled over the next days.

Today's estimated international sunspot number (ISN): 012, based on 21 stations.

Solar indices for 18 Sep 2017

Wolf number Catania013
10cm solar flux072
AK Chambon La Forêt026
AK Wingst021
Estimated Ap027
Estimated international sunspot number014 - Based on 35 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmCatania/NOAARadio burst types
None

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

All times in UTC

<< Go to daily overview page

Latest news

Support SpaceWeatherLive.com!

A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!

No Ads on SWL Pro!
No Ads on SWL Pro! Subscriptions
Donations
Support SpaceWeatherLive.com! Donate
Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2026/02/04X4.21
Last M-flare2026/03/15M1.0
Last geomagnetic storm2026/03/14Kp6 (G2)
Spotless days
Last 365 days3 days
20263 days (4%)
Last spotless day2026/02/24
Monthly mean Sunspot Number
February 202678.2 -34.3
March 202683.6 +5.4
Last 30 days59 -67.6

This day in history*

Solar flares
11998M3.67
22002M3.1
32012M2.65
41998M2.41
52000M2.06
DstG
11989-159G3
21993-90G2
32012-88G2
41994-66G2
51981-62G1
*since 1994

Social networks