Weekly Highlights of Solar and Geomagnetic Activity, 16 - 22 May 2011
 

:Product: Weekly Highlights and Forecasts
:Issued: 2011 May 24 1842 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
16 - 22 May 2011

Solar activity was at very low to low levels, with predominantly
B-class flares. A C1 flare occurred at 18/1259 UTC from Region 1218
(N16, L=168, class/area Bxo/010 on 19 May), and a long duration C2
flare occurred at 18/1830 UTC from Region 1208 (N12, L=318,
class/area Dso/100 on 09 May). A long duration B3 flare occurred at
19/0436 UTC which was associated with a filament eruption centered
near N20W25.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels.

Geomagnetic field activity was at quiet to active levels, with an
isolated minor storm levels at high latitudes during 16-17 May.
During this time, wind speeds ranged from 428-610 km/s, while Bt
ranged from 11 to 2 nT, and Bz ranged from -6 to 7 nT. The increase
in activity was due to a favorably positioned coronal hole
high-speed stream. Activity decreased to quiet levels for the rest
of the period.

Forecast of Solar and Geomagnetic Activity
25 May - 20 June 2011

Solar activity is expected to be very low, with a slight chance for
low levels between 25-30 May. Activity is expected to increase to
very low to low levels during the rest of the period, when old
Region 1208 returns during the rest of the period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at normal to moderate levels. High levels are
expected during 29 May - 06 June.

Geomagnetic field activity is expected to be at quiet levels on 25
May. Activity is expected to increase to quiet to active levels,
with isolated minor storm levels at high latitudes during 26-30 May,
due to a recurrent coronal hole high-speed stream. Activity is
expected to decrease to predominantly quiet levels during 31 May -
10 June. Activity is expected to increase to during 11 - 12 June due
to a recurrent coronal hole high-speed stream. Quiet levels are
expected for the rest of the period.