Joint USAF/NOAA Report of Solar and Geophysical Activity 23 June 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Jun 23 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 174 Issued at 2200Z on 23 Jun 2011
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was very low. There were three B class
flares in the past 24 hours. Region 1240 (S18E02) produced a B2 at
0213Z and appeared to be slowly growing. Region 1236 (N16W46) was
unchanged but produced a B5 at 1240Z and a B4 at 1407Z. Region 1239
(N16W27) was slowly decaying.
IB. Solar Activity Forecast: Solar activity is expected to be very
low with a chance for an isolated C-class flare.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field has been unsettled to active for the past 24
hours. ACE solar wind data showed elevated velocities around 600 to
700 km/s consistent with a high speed stream from a favorably
positioned coronal hole. A sudden impulse was observed at 0258Z and
measured 22 nT at the Boulder magnetometer. 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 active with a chance for minor storm periods at
mid-latitudes and isolated major storm periods at high latitudes for
tomorrow (24 June). This activity is expected as a response to the
arrival of the halo CME observed on 21 June. Conditions are
expected to decrease to unsettled to active levels for the second
day (25 June), and quiet to unsettled levels for the third day (26
June).
III. Event Probabilities 24 Jun-26 Jun
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 23 Jun 096
Predicted 24 Jun-26 Jun 095/095/090
90 Day Mean 23 Jun 103
V. Geomagnetic A Indices
Observed Afr/Ap 22 Jun 007/012
Estimated Afr/Ap 23 Jun 018/025
Predicted Afr/Ap 24 Jun-26 Jun 025/030-012/018-007/012
VI. Geomagnetic Activity Probabilities 24 Jun-26 Jun
A. Middle Latitudes
Active 30/15/05
Minor storm 30/10/01
Major-severe storm 20/05/01
B. High Latitudes
Active 25/20/05
Minor storm 35/15/01
Major-severe storm 30/10/01