Solar activity report

Viewing archive of Saturday, 23 July 2011

Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.

Report of Solar-Geophysical Activity 2011 Jul 23 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 204 Issued at 2200Z on 23 Jul 2011

IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z

Solar activity was very low. Region 1254 (S26W54) and Region 1259 (N23E02) are classified as Cao type spot groups. Both regions remained quiet and stable. Multiple B class x-ray events were observed, the largest a B5 at 23/1449 Z. The origin of the activity is just beyond the east limb and is likely returning Region 1246 (L=329).

IB. Solar Activity Forecast

Solar activity is expected to be very low to low for the next three days (24-26 July).

IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z

The geomagnetic field has been quiet to unsettled during the past 24 hours. Solar wind data observed at the ACE spacecraft indicated a decrease in velocity from 600 km/s to about 500 km/s during the period. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.

IIB. Geophysical Activity Forecast

The geomagnetic field is expected to be quiet to unsettled with a slight chance of isolated active periods for the next three days (24-26 July). The activity is forecast due to the expected arrival of another coronal hole high speed stream.

III. Event Probabilities 24 Jul to 26 Jul

Class M	01%	01%	01%
Class X	01%	01%	01%
Proton	01%	01%	01%
PCAF	green

IV. Penticton 10.7 cm Flux

  Observed       23 Jul 088
  Predicted   24 Jul-26 Jul  088/088/086
  90 Day Mean        23 Jul 096

V. Geomagnetic A Indices

  Observed Afr/Ap 22 Jul  010/010
  Estimated     Afr/Ap 23 Jul  008/008
  Predicted    Afr/Ap 24 Jul-26 Jul  006/006-005/005-009/009

VI. Geomagnetic Activity Probabilities 24 Jul to 26 Jul

A. Middle Latitudes
Active	10%	10%	15%
Minor storm	05%	05%	05%
Major-severe storm	01%	01%	01%

B. High Latitudes
Active	10%	10%	15%
Minor storm	05%	05%	05%
Major-severe storm	01%	01%	01%

All times in UTC

Previous rotation Previous day Calendar

Next day Next rotation

<< Go to daily overview page

G1 - Minor geomagnetic storm

Observed Kp: 5
Threshold reached: 23:35 UTC

Current data suggests there is a high possibility for aurora to appear at the following high latitude regions in the near future

Nuuk
Rovaniemi, Sodankylä, Utsjoki
Reykjavik
Kirkenes, Tromsø
Murmansk
Kiruna

Current data suggests there is a moderate possibility for aurora to appear at the following high latitude regions in the near future

Tórshavn
Oulu
Trondheim
Arkhangelsk
Luleå, Umeå

Current data suggests there is a slight possibility for aurora to appear at the following high latitude regions in the near future

Kuopio
Bergen
Sundsvall

Current data suggests there is a slight possibility for aurora to appear at the following middle latitude regions in the near future

Tampere
Petrozavodsk

The strength of the interplanetary magnetic field is high (20.25nT), the direction is moderately South (-15.51nT).

Latest news

Wednesday, 5 March 2025

Coronal hole faces Earth

Sunday, 23 February 2025

X2.0 solar flare from sunspot region 4001

Friday, 7 February 2025

Coronal hole faces Earth, Minor G1 geomagnetic storm watch

More news

Latest forum messages

CMEs from March 16-17 and small CH 207 Aurora- with positive BZ and negative BY 39 Filaments and prominences 738 AR4028 16 Changelog/Featurelog 167

Support SpaceWeatherLive.com!

A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!

Donate SpaceWeatherLive Pro

Support SpaceWeatherLive with our merchandise

Check out our merchandise

Latest alerts

00:18 UTC - Hemispheric Power Index

The OVATION model predicts the Hemispheric Power Index to reach 101GW at 01:06 UTC

Friday, 21 March 2025

23:45 UTC - Geomagnetic activity

Minor G1 geomagnetic storm (Kp5) Threshold Reached: 23:30 UTC

23:12 UTC - Hemispheric Power Index

The OVATION model predicts the Hemispheric Power Index to reach 77GW at 00:01 UTC

19:39 UTC - Hemispheric Power Index

The OVATION model predicts the Hemispheric Power Index to reach 53GW at 20:34 UTC

19:00 UTC - Geomagnetic activity

Minor G1 geomagnetic storm (Kp5) Threshold Reached: 18:55 UTC

Get instant alerts!

Space weather facts

Last X-flare	2025/02/23	X2.0
Last M-flare	2025/03/21	M1.2
Last geomagnetic storm	2025/03/14	Kp6- (G2)

Spotless days
Last spotless day	2022/06/08

Monthly mean Sunspot Number
February 2025	154.6 +17.6
March 2025	138.4 -16.2
Last 30 days	140.3 -10.9

This day in history*

Solar flares
1	2001	M2.65
2	2013	M2.32
3	2000	M1.51
4	2001	M1.41
5	2000	M1.26

		Dst	G
1	1990	-136	G3
2	1998	-85	G2
3	2001	-83
4	1974	-77	G3
5	1989	-75

*since 1994