lunedì 24 aprile 2017

Propagation outlook from Boulder

:Product: Weekly Highlights and Forecasts
:Issued: 2017 Apr 24 0153 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 17 - 23 April 2017

Solar activity reached low levels on 17-18 Apr due to isolated
C-class flare activity from Region 2651 (N12, L=070,
class/area=Cso/150 on 23 Apr), but solar activity was at very low
levels through the remainder of the period (19-23 Apr). The largest
event of the period, a long-duration C5/Sf flare at 18/2010 UTC with
both Type-II and IV radio emissions, had an associated CME that was
observed in C2 coronagraph imagery beginning at 18/1948 UTC. CME
analysis and WSA-Enlil modelling suggested that this event did not
have an Earth-directed component, however, it is likely that this
event reached Earth late on 21 Apr. No other Earth-directed CMEs
were observed.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels on 17-18, 21-23 Apr, moderate levels on 20 Apr, and
normal levels on 19 Apr.

Geomagnetic field activity was quiet on 17 Apr and quiet to
unsettled on 18 Apr under a nominal solar wind regime. The influence
of a recurrent, positive polarity CH HSS caused periods of G1
(Minor) geomagnetic storm conditions on 19 Apr and G1-G2
(Minor-Moderate) storm conditions on 20 Apr. The likely arrival of a
CME (from 18 Apr) combined with the onset of a CIR caused G1 (Minor)
geomagnetic storm levels late on 21 Apr. The influence of a
recurrent, negative polarity CH HSS began early on 22 Apr and caused
G1-G2 (Minor-Moderate) geomagnetic storms on 22-23 Apr.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY 24 APRIL - 20 MAY 2017

Solar activity is expected to be very low with a chance for C-class
flare activity throughout the outlook period (24 Apr-20 May).

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
likely to reach very high levels on 29-30 Apr with high levels
likely on 24-28 Apr and 06-12, 17-20 May. Normal to moderate flux
levels are expected for the remainder of the period.

Geomagnetic field activity is likely to reach G2 (Moderate)
geomagnetic storm levels on 19-20 May with G1 (Minor) geomagnetic
storms likely on 24-27 Apr and 01, 17-18 May due to the influence of
multiple, recurrent CH HSSs. Active conditions are likely on 28 Apr
and 05-06, 16 May with quiet or quiet to unsettled field activity
expected for the remainder of the period.

:Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2017 Apr 24 0153 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/wwire.html
#
#      27-day Space Weather Outlook Table
#                Issued 2017-04-24
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2017 Apr 24      84          30          5
2017 Apr 25      84          20          5
2017 Apr 26      84          20          5
2017 Apr 27      84          20          5
2017 Apr 28      84          15          4
2017 Apr 29      84           8          3
2017 Apr 30      84           5          2
2017 May 01      80          20          5
2017 May 02      75          10          3
2017 May 03      75          10          3
2017 May 04      75          10          3
2017 May 05      75          15          4
2017 May 06      75          15          4
2017 May 07      75           8          3
2017 May 08      75           8          3
2017 May 09      75           5          2
2017 May 10      75           5          2
2017 May 11      75           5          2
2017 May 12      75           5          2
2017 May 13      75           5          2
2017 May 14      75           5          2
2017 May 15      80           8          3
2017 May 16      80          15          4
2017 May 17      80          30          5
2017 May 18      80          25          5
2017 May 19      85          45          6
2017 May 20      85          50          6
(SWPC via DXLD)