Viewing archive of Thursday, 24 October 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Oct 24 1308 UTC

SIDC Forecast

Solar flares

Major flares expected (X-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
24 Oct 2013	156	015
25 Oct 2013	156	017
26 Oct 2013	151	007

Bulletin

There were six M flares and eleven C flares on the Sun during the past 24 hours. The brightest one was an M9.3 flare released by NOAA AR 11877 with peak time at 00:30 UT on October 24, and caused a Type II radio burst with estimated shock speed of 750 km/s. All C and M flares were produced either by NOAA AR 11875 or NOAA AR 11877, both of which are beta-gamma-delta regions with rapidly evolving topology. In the next 48 hours, X flares from either region are possible. Since both regions are near the central meridian, there is a substantial risk of halo CMEs and a warning condition for proton storms is issued. In the past 24 hours, solar wind has varied between about 310 and 350 km/s. In the same period, the Interplanetary Magnetic Field has varied between 5 and 8 nT. The M4.2 flare of October 22 was accompanied by a faint halo CME, which could deliver a glancing blow to Earth on October 27. Geomagnetic activity was at quiet levels (K Dourbes between 0 and 3; NOAA Kp between 0 and 1) during the past 24 hours. Active conditions (K Dourbes = 4) with isolated minor storm intervals (K Dourbes = 5) are possible in the second half of October 24 and on October 25, due to a possible glancing blow from the CME from October 22 (observed by LASCO C2 at 4:36 UT). Quiet conditions (K Dourbes < 4) are expected for October 26.

Today's estimated international sunspot number (ISN): 105, based on 13 stations.

Solar indices for 23 Oct 2013

Wolf number Catania	158
10cm solar flux	153
AK Chambon La Forêt	005
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	089 - Based on 18 stations

Noticeable events summary

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

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