- Press Release
- Sep 29, 2022
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 May 2013
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 146 Issued at 2200Z on 26 May 2013
IA. Analysis of Solar Active Regions and Activity from 25/2100Z to
26/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
26/0957Z from Region 1756 (S20W13). There are currently 5 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (27 May, 28 May,
IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 849 km/s at 25/2207Z. Total IMF reached 13 nT at 25/2258Z. The
maximum southward component of Bz reached -5 nT at 26/0615Z. Protons
greater than 10 MeV at geosynchronous orbit reached a peak level of 2
pfu at 25/2115Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 11636 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (27 May, 28 May)
and quiet levels on day three (29 May).
III. Event probabilities 27 May-29 May
Class M 25/25/25
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 26 May 120
Predicted 27 May-29 May 120/120/120
90 Day Mean 26 May 123
V. Geomagnetic A Indices
Observed Afr/Ap 25 May 025/040
Estimated Afr/Ap 26 May 016/018
Predicted Afr/Ap 27 May-29 May 010/010-007/008-006/005
VI. Geomagnetic Activity Probabilities 27 May-29 May
A. Middle Latitudes
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 25/20/20
Major-severe storm 25/20/10