[RSM] W3LPL forecast Mon/7 - Tue/8

Mon Jun 7 05:07:50 EDT 2021

I receive the PVRC Reflector emails in "digest" form.  I don't know the
algorithm for how the reflector decides it's time to send a digest.
Whatever, this time it's pretty fresh.
73, Art K3KU/VE4VTR
=========================

From: donovanf at erols.com
To: PVRC Submissions <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 7 Jun 2021 01:36:16 -0400 (EDT)
Subject: [PVRC] Normal propagation on Monday with possible below normal
intervals on Tuesday

Long distance propagation forecast for Monday and Tuesday June 7-8

My propagation forecast derived from today's NOAA/SWPC

web pages is published five days a week (M-F) in the Daily DX.

Low latitude propagation is likely to be normal through Tuesday.

Mid-latitude propagation is likely to be normal on Monday

gradually degrading to mostly normal on Tuesday.

Propagation through the auroral ovals and polar regions is likely

to be mostly normal on Monday with possible below normal

intervals on Tuesday.

Click *here* <https://services.swpc.noaa.gov/images/planetary-k-index.gif>
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.

We are in the quiet geomagnetic activity season, only about half

as many geomagnetically disturbed days occur in June and July

compared to the more geomagnetically active equinox seasons.

Sporadic-E propagation occurs every day during June and July at

mid-latitudes in the northern hemisphere making long distance

propagation up to 15,000 km sporadically available in the

17, 15, 12, 10 and 6 meter bands from sunrise through midnight

and occasionally somewhat later.

The solar flux index (SFI) is likely to be about 78 through Tuesday.

Three active regions containing 12 tiny sunspots are slightly

improving HF propagation.

160 and 80 meter propagation from North America to VK/ZL and

the south Pacific is likely to be normal through Tuesday. 40 meter

short path propagation to south Asia is likely to be mostly normal

at about 0015Z Tuesday. 40 meter short path propagation from

North America to east Asia after about 0930Z is likely to be

mostly normal on Monday with possible below normal intervals

on Tuesday.

30 meter propagation through the auroral ovals and polar regions

is likely to be mostly normal on Monday and with possible below

normal intervals on Tuesday. 30 meter propagation is always

significantly degraded within a few hours of local noon because

of E-region blanketing of long distance F2 propagation. 30 meter

night time long distance propagation in the northern hemisphere

is likely to improve due to increased ionizing solar radiation in the

northern high latitude regions caused by higher solar elevation angles

and much shorter nights with no source of ionizing solar radiation.

20 meter daytime and evening propagation through the auroral

ovals and polar regions is likely to be mostly normal on Monday

and with possible below normal intervals on Tuesday. 20 meter

northern transpolar propagation within a few hours of sunrise

and sunset is improving with increased solar ionizing radiation

on the northern polar region caused by higher solar elevation angles

24 hours per day during the midnight sun season. 20 meter long

distance propagation is significantly degraded from mid-morning

through late afternoon at low and mid-latitudes in the northern

hemisphere by F1 region midday blanketing of low angle

propagation during the summer. 20 meter nighttime long distance

propagation in the northern hemisphere is likely to improve due to

increased ionizing solar radiation in the northern high latitude

regions caused by higher solar elevation angles and much shorter

nights with no source of ionizing solar radiation.

17 and 15 meter daytime long distance propagation in the northern

hemisphere is likely to improve due to increased ionizing solar

radiation in the northern high latitude regions caused by higher

solar elevation angles and much longer days. 17, 15, 12, 10 an

6 meter sporadic-E propagation up to 15,000 km is likely to be

sporadically available from sunrise through midnight and

occasionally later through late July.

Geomagnetic disturbances *caused by coronal hole high speed*

*streams* are likely to remain mostly brief, minor and somewhat

less frequent through at least late 2021. The southward oriented

(-Bz) component of the 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 enhanced IMF

field strength 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 enhanced IMF field strength

for several hours or more *coincident with* the effects of an Earth

directed CME.

IMF field strength, solar wind speed near Earth and geomagnetic

activity are likely to be at nearly ambient levels on Monday

degrading to moderately enhanced levels on Tuesday due to

influence of coronal hole high speed stream effects. CME and

solar flare activity are not expected through Tuesday. The is a slight

chance of a brief minor geomagnetic storm on Tuesday.

Mid-latitude northern hemisphere sunset is now 71 minutes later

and daylength is 160 minutes longer than it was on the March 20th.

Daylength is increasing by less than one minute per day which is

slightly lengthening the duration of common daylight between

distant locations in the northern hemisphere. The elevation angle

of the midnight sun in the northern polar region is increasing about

two degrees per week, slowly improving 20 meter northern

trans-polar propagation.

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 http://www.solarham.net

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