Space Weather Guide

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What is Space Weather?

Most of the time space, weather is of little concern in our everyday lives. However, when the space environment is disturbed by the variable output of particles and radiation from the Sun, technologies that we depend on in our daily life, in space orbit as well as on the ground, can be affected. Some of the most dramatic space weather effects occur in association with eruptions of material from the solar atmosphere into interplanetary space. Thus, our space weather is a consequence of the behavior of the Sun, the nature of Earth's magnetic field and atmosphere, and our location in the solar system. The increasing deployment of radiation -current- and field sensitive technological systems over the last few decades and the increasing presence of complex systems in space combine to make society more vulnerable to solar-terrestrial disturbances. This has been emphasized by the large number of problems associated with the severe magnetic storms between 1989 and 1991 as the 11 year solar activity cycle peaked.

SOHO Real-time View of the Sun

Space Weather Outlook

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 May 2015


Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 141 Issued at 2200Z on 21 May 2015


IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 21/0706Z from Region 2349 (S21W10). There are currently 3 numbered sunspot regions on the disk.


IB.  Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (22 May, 23 May, 24 May).


IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 468 km/s at 21/1022Z. Total IMF reached 6 nT at 20/2106Z. The maximum southward component of Bz reached -3 nT at 21/1130Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 146 pfu.


IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (22 May, 23 May, 24 May).


III.  Event probabilities 22 May-24 May

Class M    01/01/01

Class X    01/01/01

Proton     01/01/01

PCAF       green


IV.  Penticton 10.7 cm Flux

Observed           21 May 102

Predicted   22 May-24 May 100/100/100

90 Day Mean        21 May 128


V.  Geomagnetic A Indices

Observed Afr/Ap 20 May  010/009

Estimated Afr/Ap 21 May  003/004

Predicted Afr/Ap 22 May-24 May  006/005-006/005-006/005


VI.  Geomagnetic Activity Probabilities 22 May-24 May

A.  Middle Latitudes

Active                10/10/10

Minor Storm           01/01/01

Major-severe storm    01/01/01

B.  High Latitudes

Active                20/20/20

Minor Storm           20/20/20

Major-severe storm    10/10/10


NOAA/SEC Satellite Environment

GOES X-Ray Flux

Dst Geomagnetic Index Estimate

Auroral Activity Extrapolated from NOAA POES


Dst > -20 nT


-20 nT > Dst > -50 nT


High: -50 nT > Dst > -100 nT


Dst < -100 nT


ACE Solar Wind Real-Time Data

Note: Images and text on this page are provided by NASA/ESA SOHO website. Space Weather Today from NOAA's Space Environment Center.