[RSM] W3LPL forecast thru Wednesday 2023-05-17

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 16 May 2023 01:08:33 -0400 (EDT)
Subject: [PVRC] Low and mid-latitude propagation is likely to be normal and
high latitude propagation is likely to be mostly normal through early
Wednesday improving to normal through 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 and mid-latitudes is likely to be normal through
Wednesday.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal through early Wednesday improving to normal through late
Wednesday.

VE3EN’s End-of-Day Solar Report is published at 0045Z daily at
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 55 minutes later and day length
is 132 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 15th Estimated International Sunspot Number was 106. Today's Solar
Flux Index (SFI) is 135 and likely to be about the same through Wednesday.
The sun’s visible disk has three medium and three tiny active regions
containing 43 sunspots with a total sunspot area of 330 micro-hemispheres
(about twice the surface area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

There is a slight chance of minor to moderate daytime radio blackouts
caused by M-class solar flares on Tuesday and a somewhat higher chance on
Wednesday.

The solar wind is slightly enhanced at about 480 km/second, likely to
gradually decline to weakly enhanced at about 400 km/second through early
Wednesday then reaching ambient levels less than 400 km/second through late
Wednesday. Isolated weak enhancements from a glancing CME blow are possible
through early Wednesday.

Geomagnetic activity is likely to quiet to unsettled through early
Wednesday improving to mostly quiet through 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 at about
0000Z is likely to be mostly normal early Wednesday improving to normal
late Wednesday. Short path propagation from North America to east Asia
after about 0930Z is likely to be normal through Wednesday.

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

17 and 15 meter long distance propagation is likely to be mostly normal
through early Wednesday improving to normal through late 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 on Tuesday improving to normal
on Wednesday.

12 and 10 meter long distance propagation is likely to be mostly normal
through early Wednesday improving to normal through late Wednesday. 12 and
10 meter long distance propagation crossing the north Atlantic and north
Pacific is degraded by 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 mostly normal on Tuesday improving to normal on
Wednesday.

There is a chance through Wednesday of 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 slight chance through Wednesday of propagation via the
northern equatorial ionization anomaly from the southern tier of US states
to equatorial Africa during mid-afternoon.  There is a slight chance
through Wednesday of oblique-TEP to the south Pacific and VK/ZL during late
afternoon and early evening through Wednesday. 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 then degrading significantly 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
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
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: dx.qsl.net/propagation and www.solarham.net