domenica 20 Settembre 2020
Home > Propagazione > Propagation outlook from Boulder

Propagation outlook from Boulder

:Product: Weekly Highlights and Forecasts
:Issued: 2015 Sep 21 0538 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 14 – 20 September 2015

Solar activity was low from 14-16 Sep. Activity increased to
moderate levels on 17 Sep when Region 2415 (S19, L=233, class/area
Eac/240 on 19 Sep) produced an M1/Sf flare at 17/0940 UTC. A long
duration C2/Sf flare observed at 18/0631 UTC was accompanied by Type
II (850 km/s) and Type IV radio sweeps along with a coronal mass
ejection (CME). Low levels were observed on 18-19 Sep but returned
to moderate levels on 20 Sep. Region 2420 (N09, L=108, class/area
Ekc/270 on 20 Sep) produced an M1 at 20/0503 UTC as it rotated onto
the east limb. Region 2415 produced an M2/2n flare at 20/1803 UTC
accompanied by a Type II (1358 km/s) radio sweep as well as a 320
sfu Tenflare. An associated CME was observed in SOHO LASCO C2
imagery beginning at 20/1812 UTC and a WSA-Enlil model run is in
progress to determine geoeffectiveness.

No proton events were observed at geosynchronous orbit, however, an
enhancement was observed in conjunction with the M2 flare from 20
Sep with a peak flux of 3 pfu at 20/2045 UTC.

The greater than 2 MeV electron flux at geosynchronous orbit was at
moderate to high levels from 14-18 Sep due to a combination of
effects from a CME and coronal hole high speed stream (CH HSS)
influence. Normal to moderate levels were observed on 19-20 Sep.

Geomagnetic field activity was at quiet to minor storm levels on 14
Sep due to the onset of a recurrent, positive polarity CH HSS late
in the day. Quiet to active levels persisted from 15-17 Sep as HSS
influence continued. Quiet to unsettled conditions were observed on
18 Sep as CH HSS effects subsided. Predominately quiet to unsettled
levels were observed on 19 Sep with the exception of isolated active
and minor storm periods from 19/0300-0600 UTC and 19/0600-0900 UTC,
respectively, in response to a solar sector boundary change and a
prolonged period of negative Bz. A geomagnetic Sudden Impulse of 27
nT was observed at the Boulder magnetometer on 20 Sep at 0605 UTC
indicating the arrival of the 18 Sep CME. Unsettled to severe storm
conditions were subsequently observed and then were followed by the
onset of a recurrent, positive polarity CH HSS.

FORECAST OF SOLAR AND GEOMAGNETIC ACTIVITY 21 SEPT – 17 OCT 2015

Solar activity is expected to be at low to moderate levels from 21
Sep – 02 Oct as Region 2420 makes its way across the visible disk.
Low levels are anticipated from 03-05 Oct. Low to moderate levels
are likely to return on 06 Oct when Region 2415 is expected to
rotate back into view and remain elevated through the end of the
forecast period (17 Oct).

No proton events are expected at geosynchronous orbit although a
slight chance exists from 21-22 Sep when Region 2415 rotates off of
the west limb and 06-17 Oct when it returns as it now has a history
of producing protons.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at moderate to high levels from 21-27 Sep due to
influence from various CME and CH HSS activity. Normal to moderate
levels are expected from 28 Sep to 01 Oct. Chances for high levels
return from 02-11 Oct due to effects from a series of recurrent,
positive polarity high speed streams. Predominately normal to
moderate levels are expected for the remainder of the period.

Geomagnetic field activity is expected to reach minor storm levels
early on 21 Sep due to waning effects of the 18 Sep CME and CH HSS
influence. Quiet to unsettled conditions are expected from 22-24 Sep
although analysis is ongoing to determine if and when the 20 Sep CME
will affect field activity. Unsettled to active levels are expected
from 25-26 Sep due to influence from a negative polarity CH HSS.
Quiet to unsettled conditions are expected from 27-30 Sep. A series
of recurrent positive polarity high speed streams are expected to
increase field activity to a baseline of unsettled to active
conditions from 01-09 Oct with minor storm levels likely on 01 Oct
and 05-06 Oct and major storm levels likely on 04 and 08 Oct during
peak influence as well as co-rotating interaction regions (CIRs)
preceding the onset of the individual streams. Quiet to unsettled
conditions are expected from 10-16 Oct with isolated active periods
possible during periods of sustained negative Bz as HSS influence
subsides. Unsettled to active levels are expected with a chance for
minor storm periods on 17 Oct due to positive polarity CH HSS
influence.

:Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2015 Sep 21 0539 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 2015-09-21
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2015 Sep 21     110          20          5
2015 Sep 22     110          12          3
2015 Sep 23     110           8          3
2015 Sep 24     105           8          3
2015 Sep 25     100          16          4
2015 Sep 26      95          14          3
2015 Sep 27      95           8          3
2015 Sep 28      95           8          3
2015 Sep 29     100           8          3
2015 Sep 30     100           8          3
2015 Oct 01     100          20          5
2015 Oct 02      95          15          3
2015 Oct 03      95          15          3
2015 Oct 04      95          45          6
2015 Oct 05      95          25          5
2015 Oct 06     100          18          5
2015 Oct 07     100          12          4
2015 Oct 08     105          50          6
2015 Oct 09     105          15          4
2015 Oct 10     105          12          3
2015 Oct 11     105          12          3
2015 Oct 12     100          12          3
2015 Oct 13      95          12          3
2015 Oct 14      95          12          3
2015 Oct 15      95          12          3
2015 Oct 16      90          12          3
2015 Oct 17      90          18          4
(SWPC via DXLD)

Check Also

Propagation News – 20 September 2020

We had another uninspiring week with zero sunspots. However, there was DX to be had, …

Copy Protected by Chetan's WP-Copyprotect.