[RSM] W3LPL forecast Tue-Wed, Jul 18-19

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 18 Jul 2023 02:07:13 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal with mild to
moderate degradations at mid to high latitudes during midday Tuesday and
Wednesday improving to normal conditions by late Wednesday

My propagation forecast derived from today's NOAA/SWPC web pages and twelve
other online sources (the URLs are 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
Wednesday.   Propagation crossing mid-latitudes is likely to be mostly
normal with possible mild degradations during midday Tuesday and Wednesday
improving to normal conditions by late Wednesday.   Propagation crossing
the auroral ovals and polar regions is likely to be mostly normal with
likely moderate degradations during midday Tuesday and 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 prop.kc2g.com
<http://www.prop.kc2g.com/>

Mid-latitude northern hemisphere sunrise is 14 minutes later and sunset is
seven 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 45 degrees north latitude.

Today’s Estimated International Sunspot Number is 145 and is likely to
remain about the same through Wednesday. The sun’s visible disk has three
very large and five tiny active regions containing 69 sunspots with a total
sunspot area of 1980 micro-hemispheres (about ten 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 Wednesday. There is a slight chance of strong daytime
radio blackouts caused by X-class solar flares through Wednesday.

The solar wind is likely to remain enhanced at about 500 to 600 km/second
through Tuesday, decreasing to mildly elevated levels of about 500
km/second through late Wednesday due to effects of multipole CMEs then
gradually improving to 500 km/second or less by late Wednesday.

Geomagnetic activity is likely to be quiet to active through Wednesday with
a chance of minor to moderate geomagnetic storm activity during midday
Wednesday due to the effects of multiple CMEs, then gradually improving to
mostly unsettled by late Wednesday.
160 and 80 meter propagation from North America to VK/ZL and
the South Pacific is likely to be normal through Wednesday.

40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly normal on Wednesday due to waning effects of
multiple CMEs. Short path propagation from North America to east Asia after
about 0930Z is likely to be mostly normal with possible mild to moderate
degradations during midday Tuesday and Wednesday.
30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with mild to moderate degradations during midday
Tuesday and Wednesday. 30 meter propagation is always mildly to moderately
degraded within a few 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 with mild to moderate
degradations during midday Tuesday and Wednesday. 20 meter transpolar
propagation within a few hours of sunrise and sunset is likely to be mostly
normal with mild to moderate degradations during midday Tuesday and
Wednesday. 20 meter long distance propagation at low and mid latitudes in
the northern hemisphere is usually degraded from a few hours before noon
until a few hours after noon through late August by E region and sporadic-E
blanketing of long distance low angle F2 propagation.

17 and 15 meter long distance propagation is likely to be mostly normal
with mild to moderate degradations during midday Tuesday and Wednesday. 17
and 15 meter long path propagation from North America to east Asia from
about 1200Z to 1400Z is likely to be mostly normal with possible mild to
moderate degradations through Wednesday.

12 and 10 meter long distance propagation is likely to be mostly normal
with mild to moderate degradations during midday Tuesday and Wednesday. 12
and 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 is likely to be mostly normal
with possible mild to moderate degradations through Wednesday.

6 meter long distance sporadic-E propagation up to 10,000 km occasionally
occurs in the northern hemisphere from early morning through late evening
hours but its duration and geographic extent became much more sporadic and
unreliable since mid-July. 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 Wednesday of brief 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
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 brief
isolated oblique-TEP to the south Pacific and VK/ZL during late afternoon
and early evening through Wednesday. There is a very slight chance that
stations in the lower 48 U.S. states 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.

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

The Penticton 10.7 cm solar flux index is updated daily at 1700, 2000 and
2300Z at:
https://www.spaceweather.gc.ca/forecast-prevision/solar-solaire/solarflux/sx-5-flux-en.php

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