Solar activity report

Viewing archive of Thursday, 15 September 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 Sep 15 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 258 Issued at 2200Z on 15 Sep 2011

IA. Analysis of Solar Active Regions and Activity from 14-2100Z to 15-2100Z

Solar activity was low. Nine C-class flares were observed during the period. The largest was a C4/Sf at 15/0029Z from Region 1297 (S18W64). Region 1295 (N22E30) showed growth in its trailing spots.

IB. Solar Activity Forecast

Solar activity is expected to be low with a chance for isolated M-class flares during the period (16-18 September).

IIA. Geophysical Activity Summary 14-2100Z to 15-2100Z

The geomagnetic field was at predominantly quiet levels. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels throughout the period.

IIB. Geophysical Activity Forecast

The geomagnetic field is expected to be at predominantly quiet levels on day one (16 September). Unsettled to active levels are possible late on day one, due to the expected arrival of the full halo CME observed at 14/0000Z. Activity is expected to be at unsettled to active levels, with isolated minor storm levels at high latitudes on day two (17 September) as the CME continues. Activity is expected to decrease to quiet to active levels on day three (18 September).

III. Event Probabilities 16 Sep to 18 Sep

Class M	35%	35%	35%
Class X	01%	01%	01%
Proton	01%	01%	01%
PCAF	green

IV. Penticton 10.7 cm Flux

  Observed       15 Sep 141
  Predicted   16 Sep-18 Sep  140/140/135
  90 Day Mean        15 Sep 101

V. Geomagnetic A Indices

  Observed Afr/Ap 14 Sep  005/004
  Estimated     Afr/Ap 15 Sep  004/004
  Predicted    Afr/Ap 16 Sep-18 Sep  010/010-018/020-010/015

VI. Geomagnetic Activity Probabilities 16 Sep to 18 Sep

A. Middle Latitudes
Active	25%	25%	25%
Minor storm	10%	15%	10%
Major-severe storm	01%	05%	01%

B. High Latitudes
Active	30%	30%	30%
Minor storm	15%	20%	15%
Major-severe storm	05%	05%	01%

All times in UTC

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G2 - Moderate geomagnetic storm

Observed Kp: 6
Threshold reached: 20:16 UTC

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

Oulu, Rovaniemi, Sodankylä, Utsjoki
Kirkenes, Tromsø
Murmansk, Vorkuta
Kiruna, Luleå

The solar wind speed is currently moderately high (576.3 km/sec.)

The strength of the interplanetary magnetic field is moderate (17.49nT), the direction is North (4.03nT).

The Disturbance Storm Time index predicts moderate storm conditions right now (-77nT)

The maximum X-ray flux of the past two hours is:

C7.01

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