[RSM] W3LPL forecast thru Thursday, July 13

Wed Jul 12 05:58:30 EDT 2023

(Big flare yesterday 1808Z)

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 12 Jul 2023 02:23:09 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be normal through midday
Wednesday, mostly normal through midday Thursday improving to normal
through late Thursday

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 is likely to be normal through
Thursday.   Propagation crossing the auroral ovals and polar regions is
likely to be normal through midday Wednesday, mostly normal through midday
Thursday improving to normal through late 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  Maps and data about ionospheric
conditions are updated in near real time at prop.kc2g.com
<http://www.prop.kc2g.com/>
Mid-latitude northern hemisphere sunrise is ten minutes later and sunset is
three 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 214 and is likely to
remain about the same through Thursday. The sun’s visible disk has one very
large, two large, five medium and four tiny active regions containing 107
sunspots with a total sunspot area of 1860 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 Thursday. There is a slight chance of strong daytime
radio blackouts caused by X-class solar flares through Thursday.

The solar wind is likely to remain at background levels of about 350
km/second or less through midday Wednesday, possibly increasing to
moderately elevated levels of about 450 km/second by late Wednesday then
declining to mildly elevated levels of 400 km/second or less after midday
Thursday.

Geomagnetic activity is likely to be mostly quiet through midday Wednesday
degrading to unsettled to active with a slight chance of an isolated minor
geomagnetic storm through early Thursday due to possible weak CME effects,
improving to quiet levels after midday Thursday.

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

40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly normal. Short path propagation from
North America to east Asia after about 0930Z is likely to be normal on
Wednesday and mostly normal on Thursday.
30 meter propagation through the auroral ovals and polar regions is likely
to be normal through midday Wednesday, mostly normal through midday
Thursday improving to normal through late 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 normal through midday Wednesday, mostly
normal through midday Thursday improving to normal through late Thursday.
20 meter transpolar propagation within a few hours of sunrise and sunset is
likely to be normal through midday Wednesday, mostly normal through midday
Thursday improving to normal through late Thursday. 20 meter long distance
propagation at low and mid latitudes in the northern hemisphere is usually
degraded from a few hours after sunrise until a few hours before sunset
from June through 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 normal through
midday Wednesday, mostly normal through midday Thursday improving to normal
through late Thursday. 17 and 15 meter long path propagation from North
America to east Asia from about 1200Z to 1400Z is likely to be normal on
Wednesday and mostly normal on Thursday.

12 and 10 meter long distance propagation is likely to be normal through
midday Wednesday, mostly normal through midday Thursday improving to normal
through late 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 late September. 12 and 10 meter long path propagation from North
America to western Australia from about 1200Z to 1400Z is likely to be
normal on Wednesday and mostly normal on 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

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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