Viewing archive of Tuesday, 27 October 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Oct 27 1230 UTC

SIDC Forecast

Valid from 1230 UTC, 27 Oct 2015 until 29 Oct 2015
Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

10cm fluxAp
27 Oct 2015106006
28 Oct 2015106007
29 Oct 2015106007

Bulletin

Solar activity was low. The X ray flux initially only briefly touched the C level with a C1 flare from Catania group 54 (NOAA 2436) peaking at 5:14UT. However, just before the end of the reporting period X-ray flux increased due to an ongoing C1.5 flare (peak at 12:11 UT) from a region at or beyond the East limb. The new Catania group 56 (NOAA 2440) grew as it was passing the central meridian with also another sunspot group (Catania 57) emerging behind it. Flaring is expected at C level mainly from the new regions, Catania 54 (NOAA2436) and the unnumbered region at the East limb. Yesterdays C2.1 flare seems to have caused a CME off the West limb, however currently available coronagraph images do not yet allow a conclusive analysis of its extent. Solar wind speed saw a gradual decline from around 480 km/s to 360 km/s. Total magnetic field also declined from around 6.8 nT to around 5 nT. Bz was between -3.5 nT and 4.4 nT. The magnetic field phi angle was stable in the positive sector. Geomagnetic conditions were quiet (both local K Dourbes and NOAA Kp 0-2). Solar wind conditions are expected to remain nominal with associated quiet geomagnetic conditions.

Today's estimated international sunspot number (ISN): 068, based on 18 stations.

Solar indices for 26 Oct 2015

Wolf number Catania///
10cm solar flux106
AK Chambon La Forêt005
AK Wingst002
Estimated Ap002
Estimated international sunspot number071 - Based on 32 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-flare2025/06/19X1.9
Last M-flare2025/10/03M1.2
Last geomagnetic storm2025/10/03Kp5 (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
September 2025129.8 -3.7
October 2025140.1 +10.3
Last 30 days131.3 -1.2

This day in history*

Solar flares
12012M3.35
22024M1.2
31999C9.19
42024C8.0
52023C6.6
DstG
12024-153G3
21960-112G1
32002-108G2
42012-99G2
52015-97G2
*since 1994

Social networks