[RSM] W3LPL forecast: Tuesday down, improving to normal after midday Wednesday

Tue Aug 8 05:45:15 EDT 2023

 From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 8 Aug 2023 01:31:39 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly below normal at mid and
high latitudes through late Tuesday, slowly improving to mostly normal by
early Wednesday and further improving to normal after midday Wednesday

My propagation forecast derived from today's NOAA/SWPC web pages and twelve
other online sources (the URLs included in 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 mostly normal through
midday Wednesday, degrading to mostly normal during local nighttime hours
late Tuesday and early Wednesday. Normal conditions are likely after midday
Wednesday.   Propagation crossing mid latitudes is likely to be mostly
normal through midday Wednesday, degrading to mostly below normal
during local nighttime hours late Tuesday and early Wednesday. Normal
conditions are likely after midday Wednesday.   Propagation crossing the
auroral ovals and polar regions is likely to be mostly below normal through
midday Wednesday, degrading to below normal during local nighttime hours
late Tuesday and early Wednesday. Normal conditions are likely after midday
Wednesday.
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 33 minutes later and sunset is
28 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 67 and is likely to
remain about the same through Wednesday. The sun’s visible disk has five
medium and three tiny active regions containing 21 sunspots with a total
sunspot area of 430 micro-hemispheres (about two times the surface area of
the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

Minor to moderate daytime radio blackouts caused by M-class solar flares
are likely through Tuesday, minor daytime radio blackouts caused by M-class
solar flares are likely through Wednesday. There is a very slight chance of
isolated strong daytime radio blackouts caused by X-class solar flares
through Wednesday.

Solar wind speed is likely to be moderately elevated at about 500 km/second
or more through midday Tuesday, slowly declining to mildly elevated levels
of about 450 km/second or more through early Wednesday then gradually
declining to near background levels of 400 km/second or less by late
Wednesday.

Geomagnetic activity is likely to be mostly active through late Tuesday
with likely minor to moderate geomagnetic storm intervals before midday
Tuesday due to CME and coronal hole high speed stream effects. Geomagnetic
activity is likely to be unsettled to active through midday Wednesday then
gradually improving to quiet conditions after midday Wednesday.
160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be mostly normal through midday Wednesday,
degrading to mostly normal during local nighttime hours late Tuesday and
early Wednesday. Normal conditions are likely after midday Wednesday.
40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly normal early Wednesday. Short path propagation
between North America and east Asia after about 0930Z is likely to be
mostly below normal on Tuesday and mostly normal on Wednesday.
30 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly normal through early Wednesday, degrading to below normal
during local nighttime hours after early Wednesday, gradually improving to
mostly normal after midday Wednesday. 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 Wednesday,
degrading to below normal during local nighttime hours after early
Wednesday, gradually improving to mostly normal after midday Wednesday. 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 Wednesday,
degrading to below normal during local nighttime hours after early
Wednesday, gradually improving to mostly normal after midday Wednesday. 17
and 15 meter long path propagation from North America to east Asia from
about 1200Z to 1400Z is likely to be below normal on Tuesday and mostly
normal on Wednesday.

12 and 10 meter long distance daytime propagation is likely to be mostly
normal through early Wednesday, degrading to below normal during local
nighttime hours after early Wednesday, gradually improving to mostly normal
after midday Wednesday. 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 below normal on Tuesday and mostly normal on
Wednesday.

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:
https://www.qsl.net/wa3mej/Articles/Propagation/6M%20Prop/K6MIO/Extreme%20Range%2050-MHz%20Es-%20East–West%20(EWEE).pdf
<https://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 Wednesday 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
Wednesday 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 Wednesday 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
Wednesday. 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 170 through Wednesday 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

<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
Virus-free.www.avg.com
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>