Joint USAF/NOAA Report of Solar and Geophysical Activity 16 April 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Apr 16 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 106 Issued at 2200Z on 16 Apr 2011
IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity was at low levels. Occasional C-class
flares were observed during the period. Two C5 flares were observed
from Region 1190 (N14W40): a C5/Sf flare at 16/0057Z and a C5/Sf
flare at 16/1414Z. Additionally, Region 1185 (N14W93) produced a C3
flare at 16/1653Z Regions 1190 and 1193 continue to remain the most
significant regions on the disk. The CME mentioned in the forecast
yesterday is not expected to disturb the field during the forecast
period (17-19 April).
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels, with C-class flares expected for the next three days
(17-19 April). There is also a chance for M-class flares during the
period.
IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field was at quiet levels. 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 at predominantly quiet levels for the next three days
(17-19 April).
III. Event Probabilities 17 Apr-19 Apr
Class M 40/40/40
Class X 05/05/05
Proton 05/05/05
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 16 Apr 119
Predicted 17 Apr-19 Apr 123/125/128
90 Day Mean 16 Apr 103
V. Geomagnetic A Indices
Observed Afr/Ap 15 Apr 003/006
Estimated Afr/Ap 16 Apr 002/005
Predicted Afr/Ap 17 Apr-19 Apr 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 17 Apr-19 Apr
A. Middle Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 10/10/10
Minor storm 01/01/01
Major-severe storm 01/01/01