[RSM] W3LPL forecast through Thurs, May 11

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 10 May 2023 03:03:18 -0400 (EDT)
Subject: [PVRC] Low latitude propagation is likely to be mostly normal
through Thursday. Mid-latitude propagation is likely to be mostly below
normal through midday Thursday improving to mostly normal by late Thursday.
High latitude propagation is likely to be below normal through midday
Thursday improving to mostly normal by 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 latitudes is likely to be mostly normal through
Thursday. There is a chance of moderate degradations early Thursday due to
a chance of strong geomagnetic storms.

Propagation crossing mid-latitudes is likely to be mostly below normal
through mid-day Thursday gradually improving to mostly normal by late
Thursday. There is a chance of moderate to strong degradations early
Thursday due to a chance of strong geomagnetic storms.

Propagation crossing the auroral ovals and polar regions is likely to be
below normal through mid-day Thursday gradually improving to mostly below
normal by late Thursday. There is a chance of moderate to severe
degradations early Thursday due to a chance of strong geomagnetic storms.

VE3EN’s End-of-Day Solar Report is published daily at 0045Z at
https://www.solarham.net

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

Click *here* <https://services.swpc.noaa.gov/images/station-k-index.png>
for today’s
latest planetary Kp Index, updated every three hours.

Click *here* <http://www.hamqsl.com/solar.html> for N0NBH’s current HF Band
Conditions, updated regularly.  Mid-latitude northern hemisphere sunset is
50 minutes later and day length is 120 minutes longer than it was on March
20th. 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 in the F2 region over Canada above 50 degrees
north latitude.

The May 10th Estimated International Sunspot Number was 161. Today's Solar
Flux Index (SFI) is 180 and likely to be about the same through Thursday.
The sun’s visible disk has one very large, one large and four medium and
three tiny active region containing 61 sunspots with a total sunspot area
of 1180 micro-hemispheres (about six 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 probable through Thursday. There is a slight chance of isolated strong
daytime radio blackouts caused by X-class solar flares through Thursday.

The solar wind is likely to remain strongly elevated to about 500 to 600
km/second through mid-day Thursday due to CME effects, gradually declining
to about 500 km/second by late Thursday.

Geomagnetic activity is likely to mostly active to unsettled through
Thursday. CME effects are likely to elevate geomagnetic activity to minor
to moderate geomagnetic storm levels from early through mid-day Thursday.
Energetic proton flux radiation has persisted at SWPC S1 minor solar
radiation storm warning threshold levels almost continuously since 1200Z
Tuesday. slightly degrading propagation crossing high latitudes.
https://www.swpc.noaa.gov/products/goes-proton-flux

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

40 meter short path propagation from North America to south Asia at about
0000Z is likely to be below normal early Thursday gradually improving to
mostly normal by late Thursday. Short path propagation from North America
to east Asia after about 0930Z is likely to be below normal through
Thursday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly below normal through midday Thursday gradually improving to
mostly normal by 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 mostly below normal through midday
Thursday gradually improving to mostly normal by late Thursday. 20
meter transpolar propagation within a few hours of sunrise and sunset is
likely to be mostly below normal through midday Thursday gradually
improving to mostly normal by late Thursday.

17 and 15 meter long distance propagation is likely to be mostly below
normal through midday Thursday gradually improving to mostly normal by late
Thursday. 17 and 15 meter long path propagation from North America to east
Asia from about 1200Z to 1400Z is likely to be below normal through
Thursday.

12 and 10 meter long distance propagation is likely to be mostly below
normal through midday Thursday gradually improving to mostly normal by late
Thursday. 12 and 10 meter long distance propagation crossing the north
Atlantic and north Pacific is suffering from normal seasonally lower MUFs
due to reduced free electron density in the F2 region through
mid-September. 12 and 10 meter long path propagation from North America to
east Asia from about 1200Z to 1400Z is likely to be below normal through
Thursday.

There is a chance through Thursday of 6 meter F2 trans-equatorial
propagation (TEP) from the southern tier of U.S. states to South America
from early afternoon through late evening. There is a lesser chance through
Thursday of oblique-TEP from the southern tier of US states to equatorial
Africa during mid-afternoon and to VK/ZL and the south Pacific during late
afternoon and early evening. There is a slight chance that stations at
mid-latitudes in the U.S. may briefly couple into TEP and oblique-TEP via
brief geographically focused intervals of mid-latitude sporadic-E or
enhanced F2 propagation. TEP may be enhanced during the onset of strong to
severe geomagnetic storms. 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
faster than 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

Click *here* <https://www.spaceweather.gc.ca/solarflux/sx-4-en.php> for today’s
Penticton 10.7 cm solar flux index updated at 1700Z, 2000Z and 2300Z daily.

Click *here*
<https://spaceweather.gfz-potsdam.de/fileadmin/ruggero/Kp_forecast/forecast_figures/KP_FORECAST_CURRENT.png>
for today’s
three-day GFZ Planetary K Index forecast updated every three hours.

Click *here* <http://sidc.oma.be/products/meu/> for today's SIDC Daily
Bulletin on Solar and Geomagnetic Activity updated at 1230Z daily.

Click *here* <https://www.swpc.noaa.gov/products/forecast-discussion>
for today's
SWPC Solar Activity Forecast Discussion updated at 0030Z and 1230Z daily.

Click *here* <https://www.sws.bom.gov.au/Space_Weather/1/1> for today's
Australian Space Forecast Centre Summary and Forecast updated at 2330Z
daily.

Perhaps the most useful HF propagation pages for DXers can be found at:
http://dx.qsl.net/propagation and https://www.solarham.net