mercoledì 20 maggio 2015

Propagation outlook from Boulder

:Product: Weekly Highlights and Forecasts
:Issued: 2015 May 18 0402 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 11 - 17 May 2015

Solar activity was low from 11-15 May. The largest event of the
period was a C9/1n at 13/1838 UTC associated with a filament
eruption near Region 2345 (N16, L=113, class/area Axx/020 on 13
May). Region 2339 (N13, L=129, class/area Fkc/900 on 08 May) was the
most active region on the disk and produced 19 C-class events during
the period. There were several filament eruptions observed during
the period however, none of them turned out to be geoeffective.
Solar activity decreased to very low levels for 16-17 May.

The greater than 10 MeV proton flux at geosynchronous orbit was
enhanced on 12 May reaching a peak flux of 6 pfu at 12/0720 UTC but
never crossed alert threshold.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels on 11-13 May before reaching high levels
daily for the remainder of the period in response to effects from a
negative polarity coronal hole high speed stream (CH HSS).

Geomagnetic field activity was at unsettled to active levels on 11
May and mostly unsettled levels on 12 May due to extended periods of
negative Bz. On 13 May, geomagnetic field conditions increased to
active to major storm levels due to the onset of a recurrent
negative polarity CH HSS. Quiet to unsettled levels persisted on
14-15 May as effects from the HSS subsided. Quiet conditions
prevailed for the remainder of the period.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY 18 MAY - 13 JUNE 2015

Solar activity is expected to be at very low levels with a chance
for C-class flares and a slight chance of M-class flares on 18 May
before decreasing further to only a chance for C-class flares once
Region 2339 rotates fully around the west limb on 19 May. The chance
for M-class activity increases on 25 May with the return of old
Region 2335 (S15, L=192) and remain elevated through the remainder
of the forecast period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at moderate to high levels from 18-28 May due to
residual effects from last weeks negative polarity CH HSS followed
by effects from an anticipated positive polarity HSS due to become
geoeffective on 18 May. Normal to moderate levels are expected to
prevail with the exception of 31 May-01 Jun, 04-06 Jun, and 10-12
Jun following various recurrent CH high speed streams.

Geomagnetic field activity is expected to be quiet to active on
18-19 May due to effects from a positive polarity CH HSS. Mostly
quiet conditions are expected from 20 May to 01 Jun. Quiet to
unsettled conditions with a chance for active periods are expected
on 02-03 Jun due to effects from a negative polarity HSS followed by
quiet conditions through 06 Jun. Unsettled conditions are expected
on 07 and 10 Jun as well as active to minor storm conditions on
08-09 Jun due to the anticipated return of the recurrent negative
polarity CH HSS that yielded major storm conditions this week.
Mostly quiet conditions are expected for the remainder of the
period.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2015 May 18 0403 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 2015-05-18
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2015 May 18     115          15          3
2015 May 19     105          12          4
2015 May 20      95           5          2
2015 May 21      90           5          2
2015 May 22      90           5          2
2015 May 23      90           5          2
2015 May 24      95           5          2
2015 May 25     105           5          2
2015 May 26     105           5          2
2015 May 27     105           5          2
2015 May 28     105           5          2
2015 May 29     105           8          3
2015 May 30     105           8          3
2015 May 31     110           5          2
2015 Jun 01     115           5          2
2015 Jun 02     120          15          4
2015 Jun 03     120          10          3
2015 Jun 04     125           5          2
2015 Jun 05     130           5          2
2015 Jun 06     130           5          2
2015 Jun 07     120          12          3
2015 Jun 08     120          25          5
2015 Jun 09     120          25          5
2015 Jun 10     120          12          3
2015 Jun 11     120           5          2
2015 Jun 12     120           5          2
2015 Jun 13     110           8          3
(SWPC via DXLD)