[RSM] W3LPL forecast thru Friday, Sept. 1

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Thu, 31 Aug 2023 02:23:37 -0400 (EDT)
Subject: [PVRC] Propagation crossing low and mid latitudes is likely to be
normal through Friday. Propagation crossing the auroral ovals and polar
regions is likely to be mostly normal with a chance of mild degradations
during local night time hours through Friday

My propagation forecast derived from today's NOAA/SWPC web pages and twelve
other online sources (the URLs included this forecast) is published five
days a week (M-F) in The Daily DX. All days and times in this forecast are
in UTC (Zulu) time.

Propagation crossing low and mid latitudes is likely to be normal through
Friday.   Propagation crossing the auroral ovals and polar regions is
likely to be mostly normal with a chance of mild degradations during local
night time hours through Friday.
NWRA’s Table of Space Weather Indices is updated 40 minutes after every
hour at https://spawx.nwra.com/spawx/env_latest.html

SILSO’s Estimated International Sunspot Number is updated continuously at
https://www.sidc.be/silso/DATA/EISN/EISNcurrent.png

SWPC’s estimated planetary Kp Index is updated every three hours at
https://services.swpc.noaa.gov/images/station-k-index.png

N0NBH’s current HF Band Conditions report is updated regularly at
https://www.hamqsl.com/solar.html  Near-real time maps and data about
ionospheric conditions are available at https://prop.kc2g.com

Mid-latitude northern hemisphere sunrise is 55 minutes later and sunset is
58 minutes earlier than it was on June 21st. Sunrise is about two hours
earlier and sunset is about two hours later at the 300 km altitude of the
F2 region than it is at ground level. The sun never sets today on the F2
region north of 60 degrees north latitude.

Today’s Estimated International Sunspot Number is 99 and is likely to
remain about the same through Friday. The sun’s visible disk has two large,
two medium and two tiny active regions containing 34 sunspots with a total
sunspot area of 700 micro-hemispheres (about four times the surface area of
the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

There is a slight chance of isolated minor to moderate daytime radio
blackouts caused by M-class solar flares through Friday.

Solar wind speed is likely to be at background levels at about 350
km/second or less through Thursday and slightly elevated to about 400
km/second or less though Friday.

Geomagnetic activity is likely to be primarily quiet through Thursday and
quiet to unsettled with a slight chance of isolated periods of active
geomagnetic conditions through Friday.
160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be normal through Friday.
40 meter short path propagation from North America to south Asia after
0000Z is likely to be normal through early Friday. Short path propagation
between North America and east Asia after about 0930Z is likely to be
normal through Friday.
30 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly normal with a chance of mild degradations during local night
time hours through Friday. 30 meter propagation is always mildly to
moderately degraded within several hours of local noon by E-region
blanketing of long distance low angle F2 propagation.

20 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly normal with a chance of mild degradations during local night
time hours through Friday. 20 meter long distance propagation at low and
mid latitudes in the northern hemisphere is usually degraded from several
hours before noon until several hours after noon through late August by E
region and sporadic-E blanketing of long distance low angle F2 propagation.

17 and 15 meter propagation crossing the auroral ovals and polar regions is
likely to be mostly normal with a chance of mild degradations during local
night time hours through Friday. 17 and 15 meter long path propagation from
North America to southeast and east Asia from about 1200Z to at least 1400Z
is likely to be normal through Friday.

12 and 10 meter long distance daytime propagation is likely to be mostly
normal with a chance of mild degradations during local night time hours
through Friday. 12 and especially 10 meter long distance propagation
crossing the north Atlantic and north Pacific is degraded by seasonally
lower daytime MUFs due to reduced daytime free electron density in the F2
region through late September 12 and 10 meter long path propagation from
North America to southeast and east Asia from about 1200Z to at least 1400Z
is likely to be normal through Friday.
There is a very slight chance through Friday of very brief isolated 6 meter
F2 trans-equatorial propagation (TEP) from the southern tier of U.S. states
to South America and the south Atlantic (e.g., ZD7) from early afternoon
through late evening. There is a very slight chance through Friday of very
brief isolated propagation via the northern equatorial ionization anomaly
from the southern tier of US states to equatorial Africa during
mid-afternoon.  There is a very slight chance through Friday of very brief
isolated oblique-TEP from the southern tier of US states to the south
Pacific and VK/ZL during late afternoon and early evening through Friday.
There is a very slight chance that more northerly US stations may briefly
couple into TEP and oblique-TEP via geographically focused intervals of
mid-latitude sporadic-E propagation. TEP may be enhanced during the onset
of strong to severe solar flares and geomagnetic storms then significantly
degrading after initial enhancement. See K6MIO’s excellent article on 6
meter TEP, oblique-TEP, TEP-related and mid-latitude sporadic-E linking to
TEP beginning on page 9 at: http://www.oh3ac.fi/QEX-2016-11.pdf

Persistent southward orientation (-Bz) of the north-south component of the
interplanetary magnetic field (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 IMF field strength of about 5 nanoteslas
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
IMF field strength mildly stronger than 5 nanoteslas for several hours
or more coincident with the effects of an Earth directed CME and solar wind
exceeding 500 km/second.   The Penticton 10.7 cm solar flux index is likely
to remain at about 139 through Friday and is updated daily at 1700, 2000
and 2300Z at:
https://www.spaceweather.gc.ca/forecast-prevision/solar-solaire/solarflux/sx-5-flux-en.php

Real time geomagnetic data including Bz orientation, IMF field strength,
solar wind speed and short term k-index forecast are available at:
https://www.swpc.noaa.gov/products/geospace-geomagnetic-activity-plot

Today's three-day GFZ Planetary K Index forecast is updated every three
hours at:
https://spaceweather.gfz-potsdam.de/fileadmin/ruggero/Kp_forecast/forecast_figures/KP_FORECAST_CURRENT.png

Today's SIDC Daily Bulletin on Solar and Geomagnetic Activity is
updated daily at 1230Z at:
https://www.sidc.be/spaceweatherservices/data/ClassicalRWCproducts/meu

Today's SWPC Solar Activity Forecast Discussion is updated daily at 0030Z
and 1230Z at: https://www.swpc.noaa.gov/products/forecast-discussion

Today's Australian Space Forecast Centre Summary and Forecast is updated
daily at 2330Z at: https://www.sws.bom.gov.au/Space_Weather/1/1

Perhaps the most useful HF propagation pages for DXers can be found at:
http://dx.qsl.net/propagation and https://www.solarham.net