lunedì 7 agosto 2017

Propagation outlook from Boulder

:Product: Weekly Highlights and Forecasts
:Issued: 2017 Aug 07 0315 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 31 July - 06 August 2017

Solar activity was mostly at very low levels with low levels
observed on 01 August due to an isolated C1 flare observed at
01/0747 UTC. Region 2670 (S05, L=119, class/area Cso/160 on 02 Aug)
rotated around the east limb on 02 Aug. This region was the return
of old Region 2665 which was responsible for two M-class flares as
well as a fast halo CME on the far side of the Sun. However, during
its return on the visible disk, the region has been relatively quiet
and stable, only managing to produce B-class flares with the
exception of the aforementioned C1 flare that occurred as it was
rounding the eastern limb. No Earth-directed coronal mass ejections
were observed during the period.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
moderate levels on 04 Aug and high levels from 31 Jul-03 Aug and
again from 05-06 Aug. The largest flux of the period was 8,649 pfu
observed at 06/1715 UTC.

Geomagnetic field activity ranged from quiet to active levels over
the period. The period began at nominal levels with solar wind
speeds near 340 km/s and total field around 4 nT. A solar sector
boundary crossing from a positive sector to a negative sector was
observed around midday on 01 Aug along with an increase in total
field to near 10 nT and an increase in solar wind speed to near 450
km/s. A general decrease in total field and solar wind speed to
nominal levels was observed on 02 Aug. The geomagnetic field
responded with quiet conditions on 31 Jul and 02 Aug with an
isolated unsettled period on 01 Aug. At approximately 03/1000 UTC,
an increase in total field was observed to 20 nT followed by an
increase in solar wind speed to near 750 km/s as a corotating
interaction region preceded an positive polarity coronal hole high
speed stream (CH HSS). Phi angle rotated into a mostly positive
orientation around 04/0220 UTC and remained positive through the
rest of the period. Solar wind speed began a slow decline late on 05
Aug after having reached a maximum of 794 km/s at 05/1216 UTC. Quiet
to active levels were observed on 03 Aug and 05-06 Aug with
unsettled to active levels on 04 Aug.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY 7 AUGUST - 2 SEPTEMBER 2017

Solar activity is expected to be at very low levels throughout the
forecast period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach moderate levels on 08, 17, and 31 Aug while high
levels are expected on 07, 09-16, 18-30 Aug and from 01-02 Sep due
to CH HSS influence.

Geomagnetic field activity is expected to be unsettled to active
levels from 07-09 Aug, 17-22 Aug, and 30 Aug-02 Sep with G1 (Minor)
geomagnetic storm levels likely on 18, 31 Aug and again on 01 Sep
due to recurrent CH HSS activity.

:Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2017 Aug 07 0315 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 2017-08-07
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2017 Aug 07      74           8          3
2017 Aug 08      74          10          4
2017 Aug 09      74           8          3
2017 Aug 10      74           5          2
2017 Aug 11      74           5          2
2017 Aug 12      74           5          2
2017 Aug 13      74           5          2
2017 Aug 14      72           5          2
2017 Aug 15      70           5          2
2017 Aug 16      70           7          3
2017 Aug 17      70          16          4
2017 Aug 18      70          18          5
2017 Aug 19      70          16          4
2017 Aug 20      70          14          4
2017 Aug 21      70          12          3
2017 Aug 22      70          10          3
2017 Aug 23      70           7          3
2017 Aug 24      70           5          2
2017 Aug 25      70           5          2
2017 Aug 26      70           5          2
2017 Aug 27      72           5          2
2017 Aug 28      74           5          2
2017 Aug 29      74           5          2
2017 Aug 30      74          12          4
2017 Aug 31      74          24          5
2017 Sep 01      74          18          5
2017 Sep 02      74          16          4
(SWPC via DXLD)