[RSM] W3LPL forecast thru Thurs; please QSO W1AW/KH6 in IARU

Wed Jul 5 05:55:57 EDT 2023

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 5 Jul 2023 00:57:11 -0400 (EDT)
Subject: [PVRC] Propagation crossing low and mid-latitudes, the auroral
ovals and polar regions is likely to be above normal though Thursday

Please look for ARRL Headquarters station W1AW/KH6 from 1200Z Saturday
through 1200Z Sunday on both CW and SSB during the IARU HF Championship.

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 and mid-latitudes, the auroral ovals and polar
regions is likely to be above normal through Thursday.  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   prop.kc2g.com
<http://www.prop.kc2g.com/> provides near-real time maps and data about
ionospheric conditions.

Mid-latitude northern hemisphere sunset is unchanged and sunrise is five
minutes later 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 122 and is likely to
remain about the same through Thursday. The  visible solar disk has one
very large, three medium and two tiny active regions containing 61 sunspots
with a total sunspot area of 1310 micro-hemispheres (about seven 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 on Wednesday, declining to a chance on Thursday as active region
3354 rotates off the visible solar disk. There is a very slight chance of
strong daytime radio blackouts caused by X-class solar flares through
Thursday.

The solar wind further declined to background levels at 351 km/second on
Wednesday and is likely to remain at background levels of about 350
km/second or less through Thursday.

Geomagnetic activity is likely to remain quiet through Thursday. There is a
slight chance of brief unsettled to active intervals through Thursday due
to weak coronal hole high speed stream effects.

160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be above normal through Thursday.

40 meter short path propagation from North America to south Asia after
0000Z is likely to be above normal through Thursday. Short path propagation
from North America to east Asia after about 0930Z is likely to be above
normal through Thursday.

30 meter propagation through the auroral ovals and polar regions is likely
to be above normal through Thursday. 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 above normal through Thursday. 20
meter transpolar propagation within a few hours of sunrise and sunset is
likely to be above normal through Thursday. 20 meter long distance
propagation at low and mid latitudes in northern hemisphere is usually
degraded during daylight hours from June through August by E region and
sporadic-E blanketing of long distance F2 propagation.

17 and 15 meter long distance propagation is likely to be above normal
through Thursday. 17 and 15 meter long path propagation from North America
to east Asia from about 1200Z to 1400Z is likely to be above normal through
Thursday.

12 and 10 meter long distance propagation is likely to be above normal
through Thursday. 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
mid-September. 12 and 10 meter long path propagation from North America to
western Australia from about 1200Z to 1400Z is likely to be above normal
through Thursday.

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 through at least mid-July, but its duration and geographic extent is
both sporadic and unpredictable. 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 Thursday 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 Thursday 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 Thursday of brief
isolated oblique-TEP to the south Pacific and VK/ZL during late afternoon
and early evening through Thursday. 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

We are in the summer solstice season when geomagnetic disturbances are less
severe, shorter duration and occur about half as often as during the
equinox seasons.

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

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