[RSM] W3LPL forecast, format-free
Art Boyars
artboyars at gmail.com
Wed Aug 4 15:53:37 EDT 2021
My regular copy-and-paste has been rejected several times since last
night. For my last try today, I've tried removing the formatting. That
will leave you without clickable links.
73, Art K3KU/VE4VTR
From: donovanf at erols.com
To: PVRC Reflector <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 4 Aug 2021 00:27:26 -0400 (EDT)
Subject: [PVRC] Normal propagation is likely through Thursday August 5th
My propagation forecast derived from today's NOAA/SWPC
web pages is published five days a week (M-F) in the Daily DX.
Propagation crossing low and mid latitudes, the auroral ovals
and polar regions is likely to be normal through Thursday.
Click here for today’s latest planetary Kp Index, updated every three hours.
Click here for N0NBH’s current HF Band Conditions, updated regularly.
We are in a mostly quiet to infrequently geomagnetically active
first two weeks in August as we transition into mildly active
geomagnetic activity during the last weeks in August followed by
the geomagnetically active autumn equinox season from early
September through late October.
Sporadic-E propagation will be shorter duration and less reliable
through mid August at mid-latitudes in the northern hemisphere
making long distance propagation up to about 8,000 km
intermittently available in the 17, 15, 12, 10 and 6 meter bands
from shortly after sunrise until a few hours after sunset.
The solar flux index (SFI) is likely to be 76 or less through Thursday.
The sun’s visible disk has one decaying small active region with
three tiny sunspots.
https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg
160 and 80 meter propagation from North America to VK/ZL
and the south Pacific is likely to be seasonably normal through
Thursday. 40 meter short path propagation to south Asia at about
0015Z is likely to be normal through Thursday. 40 meter short
path propagation from North America to east Asia after about
0930Z is likely to be normal through Thursday.
30 meter propagation through the auroral ovals and polar regions
is likely to be normal through Thursday. 30 meter propagation is
always significantly degraded within a few hours of local noon
because of E-region blanketing of long distance F2 propagation.
30 meter night time long distance propagation in the northern
hemisphere is likely to improve due to increased ionizing solar
radiation in the northern high latitude regions caused by moderately
higher solar elevation angles and fairly short nights with no source
of ionizing solar radiation.
20 meter daytime and evening propagation through the auroral
ovals and polar regions is likely to be normal through Thursday.
20 meter northern transpolar propagation within a few hours of
sunrise and sunset is improving with longer duration solar ionizing
radiation on the northern polar region caused by relatively high
solar elevation angles 24 hours per day during the steadily waning
midnight sun season. 20 meter long distance propagation is
significantly degraded from mid-morning through late afternoon
at low and mid-latitudes in the northern hemisphere by F1 region
mid-day blanketing of low angle long distance propagation during
the summer. 20 meter late afternoon, nighttime and early morning
long distance propagation in the northern hemisphere is likely to
improve due to increased ionizing solar radiation in the northern
high latitude regions caused by moderately high solar elevation
angles and fairly short nights with no source of ionizing solar radiation.
17 and 15 meter daytime long distance propagation in the northern
hemisphere is likely to slightly improve due to increased ionizing
solar radiation in the northern high latitude regions caused by
moderately high solar elevation angles and moderately long
mid-summer days. 17, 15, 12, 10 and 6 meter sporadic-E propagation
up to 8,000 km is likely to be intermittent, short duration and
unreliable from a few hours after sunrise until a few hours after
sunset through mid August.
Geomagnetic disturbances caused by coronal hole high speed stream
effects are likely to remain mostly brief, minor and somewhat less
frequent through at least late 2021. The southward oriented (-Bz)
component of the IMF plays a crucial but unpredictable role in
triggering all geomagnetic storms. Brief minor to moderate
geomagnetic storms may be gradually triggered when the IMF
persists in a southward orientation (-Bz) with enhanced IMF field
strength for several hours coincident with the effects of an Earth
directed coronal hole high speed stream. More frequent, longer
duration, minor to severe geomagnetic storms may be triggered
suddenly and unpredictably when the IMF persists in a southward
orientation (-Bz) with enhanced IMF field strength for several hours
or more coincident with the effects of an Earth directed fast CME.
The solar wind is likely to be near background levels until mid-day
Thursday when it is likely to be moderately enhanced ahead of the
arrival of the effects of a coronal hole high speed stream. The
geomagnetic field is likely to be quiet through mid-day Thursday
then unsettled ahead of the arrival of the effects of a coronal hole
high speed stream. CME effects and solar flares strong enough to
affect HF propagation are not likely through Thursday.
Mid-latitude northern hemisphere sunset is now 21 minutes earlier
and daylength is 50 minutes shorter than it was on the June 21st.
Daylength and solar elevation angle in the northern polar region
are steadily declining due to diminishing summer solstice effects.
Click here for today’s Penticton 10.7 cm solar flux index updated at 1700Z,
2000Z and 2300Z daily.
Click here for today’s three-day GFZ Planetary K Index forecast updated
every three hours.
Click here for today's SIDC Daily Bulletin on Solar and Geomagnetic
Activity updated at 1230Z daily.
Click here for today's SWPC Solar Activity Forecast Discussion updated at
0030Z and 1230Z daily.
Click here for today's Australian Space Forecast Centre Summary and
Forecast updated at 2330Z daily.
Perhaps the most useful HF propagation pages for DXers can be found at:
http://dx.qsl.net/propagation and http://www.solarham.net
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