[RSM] W3LPL forecast thru Tues/10

[Art Boyars]

Formatted version was blocked again.

Art K3KU/VE4VTR

From: donovanf at erols.com
To: PVRC Submissions <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 9 Aug 2021 00:04:14 -0400 (EDT)
Subject: [PVRC] Mostly normal near solar minimum propagation through
Tuesday August 10th

My propagation forecast derived from today's NOAA/SWPC

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



Propagation crossing low and mid latitudes is likely to be normal

through Tuesday.



Propagation crossing the auroral ovals and polar regions is likely

to be normal on Monday, mostly normal with below normal

intervals early Tuesday, then normal through late Tuesday



Click here for today’s latest planetary Kp Index, updated every three hours.

Click here for N0NBH’s current HF Band Conditions, updated regularly.



We are in a mostly quiet to infrequent geomagnetically active period

during the first two weeks in August as we transition into mildly

active geomagnetic activity during the last weeks in August.

The more geomagnetically active autumn equinox season runs

from September through late October.



Sporadic-E propagation will be shorter duration and less reliable

through mid-August at mid-latitudes in the northern hemisphere

making long distance propagation up to about 8,000 km intermittently

available in the 17, 15, 12, 10 and 6 meter bands from a few hours

after sunrise until a few hours after sunset.



The solar flux index (SFI) is likely to be 73 or less through Tuesday.

The sun’s visible disk is spotless.

https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg



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

and the south Pacific is likely to be seasonably normal through

Tuesday. 40 meter short path propagation to south Asia at about

0015Z is likely to be mostly normal with below normal intervals

through Tuesday. 40 meter short path propagation from North

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

through Tuesday.



30 meter propagation through the auroral ovals and polar regions

is likely to be normal on Monday, normal with below normal intervals

early Tuesday, then normal through late 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

moderately higher solar elevation angles and fairly short 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 normal on Monday, normal with

below normal intervals early Tuesday, then normal through late

Tuesday. 20 meter northern transpolar propagation within a few hours

of sunrise and sunset is improving with longer duration solar ionizing

radiation on the northern polar region caused by relatively high solar

elevation angles 24 hours per day during the steadily waning 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 mid-day

blanketing of low angle long distance propagation during the summer.

20 meter late afternoon, nighttime and early morning 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 moderately high solar elevation angles and fairly short nights

with no source of ionizing solar radiation.



17 and 15 meter daytime long distance propagation in the northern

hemisphere is likely to be slightly improved due to increased ionizing

solar radiation in the northern high latitude regions caused by

moderately high solar elevation angles and moderately long

mid-summer days. 17, 15, 12, 10 and 6 meter sporadic-E propagation

up to 8,000 km is likely to be intermittent, short duration and

unreliable from a few hours after sunrise until a few hours after

sunset through mid August.



Geomagnetic disturbances caused by coronal hole high speed stream

effects 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 fast CME.



The solar wind is likely to be slightly enhanced through Tuesday

due to mild coronal hole high speed stream effects. The geomagnetic

field is likely to be quiet on Monday, quiet with unsettled intervals

early Tuesday, then quiet through late Tuesday. CME effects and

solar flares strong enough to affect HF propagation are not likely

through Tuesday.



Mid-latitude northern hemisphere sunset is now 26 minutes earlier

and daylength is 60 minutes shorter than it was on the June 21st.

Daylength and solar elevation angle in the northern polar region are

steadily declining due to diminishing summer solstice effects.


Click here for today’s Penticton 10.7 cm solar flux index updated at 1700Z,
2000Z and 2300Z daily.

Click here for today’s three-day GFZ Planetary K Index forecast updated
every three hours.

Click here for today's SIDC Daily Bulletin on Solar and Geomagnetic
Activity updated at 1230Z daily.

Click here for today's SWPC Solar Activity Forecast Discussion updated at
0030Z and 1230Z daily.

Click here 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