[RSM] W3LPL propagation forecast Tue-Wed, May 4-5.

[Art Boyars]

I've been very busy and I've missed a few days' reports.  (Note that I am
sending this at 3:40AM.  I get my PVRC Reflector emails in a digest,and
sometimes there is a delay.) I hope I did not cause you to miss an ATNO.

73, Art VE4VTR/K3KU

From: donovanf at erols.com
To: PVRC List <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 4 May 2021 01:36:53 -0400 (EDT)
Subject: [PVRC] Mostly normal -- but near solar minimum -- conditions
likely through Wednesday

Long distance propagation forecast for Tuesday and Wednesday May 4-5



My propagation forecast derived from today's NOAA/SWPC web

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



Low and mid-latitude propagation is likely to be normal through

Wednesday. Propagation through the auroral ovals and polar regions

is likely mostly normal through Wednesday.



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.



The solar flux index (SFI) is likely to be about 72 through Wednesday.

The visible disk is spotless for the third day in a row. Sunspots are

likely to return to the visible disk later this week.



160 and 80 meter short path propagation from North America to

VK/ZL and the south Pacific is likely to be normal through Wednesday.

40 meter short path propagation to south Asia is likely to be mostly

normal at about 0015Z Wednesday. 80 and 40 meter short path

propagation from North America to east Asia after about 0930Z

is likely to be mostly normal through Wednesday.



30 meter propagation through the auroral ovals and polar regions

is likely to be mostly normal through Wednesday. 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 propagation in the northern

hemisphere is likely to improve slightly mostly due to longer

daylight duration.



20 meter daytime and evening propagation through the auroral ovals

and polar regions is likely to be mostly normal through Wednesday.

20 meter northern transpolar propagation within a few hours of

sunrise and sunset will steadily improve with gradually increasing

electron density in the polar F2 region through June. 20 meter

night time long distance propagation in the northern hemisphere

is likely to improve slightly mostly due to longer daylight duration.



17 and 15 meter daytime long distance propagation in the northern

hemisphere is likely to improve slightly mostly due to longer daylight

duration. 12 and 10 meter daytime long distance propagation is likely

to be mostly unreliable and mostly limited to propagation from

North America to Southern Africa, South Atlantic, South America

and South Pacific regions.



Geomagnetic disturbances *caused by coronal hole high speed streams*

are likely to remain mostly brief, minor and less frequent through

at least late 2021. The north-south (Bz) component of the IMF plays

a *crucial role* in triggering all geomagnetic storms. Brief minor to

moderate geomagnetic storms may be gradually triggered when

Bz 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* when

Bz 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 moderately enhanced by coronal hole

high speed stream effects on Tuesday and near ambient levels on

Wednesday. Geomagnetic storms and earth directed solar flares and

CMEs strong enough to affect HF propagation are not likely through

Wednesday.



Mid latitude northern hemisphere sunset is now 43 minutes later and

daylength is 108 minutes longer than it was on the March 20th.

Daylength is increasing by two minutes per day which is steadily

lengthening the duration of common daylight between distant locations

in the northern hemisphere. The The elevation angle of the midnight sun

in the northern polar region is increasing about three degrees per week,

steadily improving 20 meter northern trans-polar propagation through June.



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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