Joint USAF/NOAA Report of Solar and Geophysical Activity 1 May 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 May 01 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 121 Issued at 2200Z on 01 May 2011
IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 01/2100Z: Solar activity was low. Region 1195 (S16W99) produced
the sole event of the period, a C1 flare at 01/0814Z.
IB. Solar Activity Forecast: Solar activity is forecast to be very
low to low for the next 3 days (2-4 May).
IIA. Geophysical Activity Summary 30/2100Z to 01/2100Z:
The geomagnetic field was unsettled to active at mid latitudes. Minor
to major storm conditions occurred at high latitudes due to Coronal
Hole (CH) high-speed stream (HSS) effects. Solar winds speeds were
sustained above 620 km/s during the period. 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 mostly unsettled to active with a chance for a minor
storm on day 1 (2 May). Conditions are forecast to be unsettled to
active on day 2 (3 May) and return to quiet on day 3 (4 May) as CH
HSS effects are expected to subside.
III. Event Probabilities 02 May-04 May
Class M 10/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 01 May 106
Predicted 02 May-04 May 105/100/100
90 Day Mean 01 May 108
V. Geomagnetic A Indices
Observed Afr/Ap 30 Apr 017/024
Estimated Afr/Ap 01 May 016/022
Predicted Afr/Ap 02 May-04 May 012/015-008/010-005/005
VI. Geomagnetic Activity Probabilities 02 May-04 May
A. Middle Latitudes
Active 40/30/20
Minor storm 30/10/01
Major-severe storm 05/01/01
B. High Latitudes
Active 50/40/20
Minor storm 25/15/01
Major-severe storm 10/01/01