[RSM] W3LPL forecast thru Tuesday, Aug 8

Mon Aug 7 09:46:20 EDT 2023

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 7 Aug 2023 02:20:01 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal through early
Tuesday, significantly degrading to mostly below normal at mid and high
latitudes during local nighttime hours after early Tuesday, then gradually
improving to mostly normal after midday Tuesday

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 latitudes is likely to be normal through early
Tuesday, degrading to mostly normal after early Tuesday, gradually
improving to normal after midday Tuesday.   Propagation crossing mid
latitudes is likely to be normal through early Tuesday, degrading to mostly
below normal during local nighttime hours after early Tuesday, gradually
improving to normal after midday Tuesday.   Propagation crossing the
auroral ovals and polar regions is likely to be mostly normal through early
Tuesday, degrading to below normal during local nighttime after early
Tuesday, gradually improving to mostly normal after midday Tuesday.
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 prop.kc2g.com
<http://www.prop.kc2g.com/>

Mid-latitude northern hemisphere sunrise is 32 minutes later and sunset is
26 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 53 degrees north latitude.

Today’s Estimated International Sunspot Number is 159 and is likely to
remain about the same through Tuesday. The sun’s visible disk has one
large, five medium and one tiny active region containing 27 sunspots with a
total sunspot area of 860 micro-hemispheres (about five times the surface
area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

Minor daytime radio blackouts caused by M-class solar flares are likely
during Monday declining to a chance of minor daytime radio blackouts during
Tuesday. There is a slight chance of isolated strong daytime radio
blackouts caused by X-class solar flares during Monday.

Solar wind speed is likely to be mildly enhanced at about 400 km/second or
more through early Tuesday, increasing to moderately elevated levels of
about 500 km/second or more after early Tuesday then gradually declining to
mildly elevated levels of about 400 km/second or more after midday Tuesday.

Geomagnetic activity is likely to be mostly unsettled to active through
late Monday due to CME and coronal hole high speed stream effects then
improving to mostly quiet through early Tuesday. Minor geomagnetic storm
conditions are expected to commence after early Tuesday due to the effects
of multiple CMEs, gradually improving to mostly unsettled after midday
Tuesday.
160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be normal through early Tuesday, degrading
mostly normal after early Tuesday, gradually improving to normal after
midday Tuesday.

40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly normal early Tuesday. Short path propagation
between North America and east Asia after about 0930Z is likely to be
mostly normal on Monday and mostly below normal on Tuesday.
30 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly normal through early Tuesday, degrading to below normal during
local nighttime hours after early Tuesday, gradually improving to mostly
normal after midday Tuesday. 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 daytime and evening propagation through the auroral ovals and
polar regions is likely to be mostly normal through early Tuesday,
degrading to below normal during local nighttime hours after early Tuesday,
gradually improving to mostly normal after midday Tuesday. 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 daytime and evening propagation through the auroral ovals
and polar regions is likely to be mostly normal through early Tuesday,
degrading to below normal during local nighttime hours after early Tuesday,
gradually improving to mostly normal after midday Tuesday. 17 and 15 meter
long path propagation from North America to east Asia from about 1200Z to
1400Z is likely to be mostly normal through Tuesday.

12 and 10 meter long distance daytime propagation is likely to be mostly
normal through early Tuesday, degrading to below normal after early
Tuesday, gradually improving to mostly normal after midday Tuesday. 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
western Australia from about 1200Z to 1400Z is likely to be mostly normal
through Tuesday.

There is a very slight chance of 6 meter long distance sporadic-E
propagation up to about 8000 km in the northern hemisphere from mid-morning
through early evening. Long distance sporadic-E is very unreliable, very
sporadic and much shorter in duration as we approach the end of regular
sporadic-E propagation in mid-August. See K6MIO’s excellent article about 6
meter long distance sporadic-E:
www.qsl.net/wa3mej/Articles/Propagation/6M%20Prop/K6MIO/Extreme%20Range%2050-MHz%20Es-%20East%E2%80%93West%20(EWEE).pdf

There is a very slight chance through Tuesday 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
Tuesday 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 Tuesday 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
Tuesday. 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 when the solar
wind exceeds about 500 km/second.   The Penticton 10.7 cm solar flux index
is likely to remain at about 170 through Tuesday 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

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