Joint USAF/NOAA Report of Solar and Geophysical Activity 30 April 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Apr 30 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 120 Issued at 2200Z on 30 Apr 2011
IA. Analysis of Solar Active Regions and Activity from 29/2100Z
to 30/2100Z: Solar activity was low. Regions 1195 (S16W80) and 1199
(N20W74) produced a few C-class flares during the period.
IB. Solar Activity Forecast: Solar activity is forecast to be low
with a chance for a M-class flare on days 1 and 2 (1-2 May), before
Regions 1195 and 1199 rotate off the disk. Low activity is expected
on day 3 (3 May).
IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z:
The geomagnetic field ranged from unsettled to minor storm conditions
as the result of coronal hole (CH) high-speed stream (HSS) effects.
The solar wind speeds at the ACE spacecraft ranged between 640 km/s
and 700 km/s during the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to range from unsettled to active conditions with isolated
minor storms possible for days 1 and 2 (1-2 May). Mostly quiet to
unsettled conditions are expected on day 3 (3 May), when CH HSS
effects begin to subside.
III. Event Probabilities 01 May-03 May
Class M 25/25/05
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 30 Apr 110
Predicted 01 May-03 May 110/110/105
90 Day Mean 30 Apr 108
V. Geomagnetic A Indices
Observed Afr/Ap 29 Apr 008/012
Estimated Afr/Ap 30 Apr 015/025
Predicted Afr/Ap 01 May-03 May 015/018-010/010-008/008
VI. Geomagnetic Activity Probabilities 01 May-03 May
A. Middle Latitudes
Active 50/40/30
Minor storm 40/30/10
Major-severe storm 10/05/01
B. High Latitudes
Active 25/50/40
Minor storm 50/25/15
Major-severe storm 15/10/05