Viewing archive of Thursday, 22 August 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Aug 22 1224 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
22 Aug 2013	125	016
23 Aug 2013	125	006
24 Aug 2013	128	026

Bulletin

A C4.2 flare on 22 August at 5h00 UT was the strongest event of the past 24 hours. The flare originated from NOAA AR 1818, which is currently located at the west limb. NOAA AR 1820 is the strongest candidate for further C-class flaring, given it's magnetic complexity. There is a slight chance for M-class flaring. No Earth directed CMEs were observed. Solar wind speed as observed by ACE has evolved from about 460 km/s to 520 km/s with a maximum of 580 km/s. The magnitude of the interplanetary magnetic field is varying between 5 and 10 nT, with a fluctuating Bz component between -5 and +5 nT. Current geomagnetic conditions are unsettled to active; with both K at Dourbes and estimated NOAA Kp making excursions to K=4. Geomagnetic activity is expected to return to quiet levels in the next few hours. A new increase to active levels is predicted on 23 August in the afternoon due to the arrival of the CME of 20 August. On 24 and 25 August we expect effects of the CME of 21 August, combined with some minor influence of a fast speed stream from two small coronal holes, one in the southern hemisphere that just past the central meridian and another low latitude in the northern hemisphere currently at a central position.

Today's estimated international sunspot number (ISN): 095, based on 13 stations.

Solar indices for 21 Aug 2013

Wolf number Catania	///
10cm solar flux	130
AK Chambon La Forêt	037
AK Wingst	024
Estimated Ap	023
Estimated international sunspot number	100 - Based on 22 stations

Noticeable events summary

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

All times in UTC

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