[SFDXA] W4HM Daily HF-MF Radio Wave Propagation Forecast #2019-144

Thu May 23 13:55:17 EDT 2019

*#144 issued Thursday May 23, 2019 at 1400 UTC*

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*GLOBAL (HF-MF 3000-30000 kHz- 300-3000 kHz) RADIO WAVE PROPAGATION 
CONDITIONS EXPECTED-***

**

*Radio wave propagation condition ???trend??? on May 23, 2019- STEADY.*

**

*Radio wave propagation condition ???trend??? on May 24, 2019- STEADY.*

**

*Radio wave propagation condition ???trend??? on May 25, 2019- MINOR 
DETERIORATION.*

**

*We are now moving into the northern hemisphere HF-MF radio wave 
propagation summer season.*

**

*The 14000- 30000 kHz frequency range closes later due to more sun light 
illuminating the ionosphere than in the southern hemisphere. But the 
maximum usable frequency (MUF) is lower than in the southern hemisphere 
as heating in the F2 layer of the ionosphere is higher and the layer 
ions less concentrated.*

**

*Almost d**aily during the northern hemisphere summer season you will 
find that the 25600- 26100 kHz and 28000-29700 kHz frequency ranges will 
open via short north-south and east-west propagation paths via sporadic 
E (Es). Also when multiple sporadic E (Es) clouds form and line up 
favorably much longer propagation paths open up on east-west paths. And 
last but not least north-south propagation paths occur across the 
equator via trans equatorial propagation (TEP).*

**

*NORTHERN HEMISPHERE HIGH FREQUENCY(HF) RADIO WAVE PROPAGATION FORECAST 
*s**g*-*

**

*Received RF signal strength scale-*

*Very Good- +1 over S9 or greater*

*Good- S7-9*

*Fair- S4-6*

*Poor- S1-3*

*Very Poor- S0*

**

*3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 at night and S1-2 at 
day,

6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 at night and
S4-7 at day,

13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 
at night and S4-6 at day,

21000-21850 kHz- S0 at night and S1-2 at day,

24890-24990, 25600-26100 kHz- S0 at night and S0-1 at day,

*

*28000-29700 kHz- S0 at night and S0 at day.*

**

*---------------------------------------------------------------------------------------------------------------------*

**

*We are now moving into the southern hemisphere HF-MF radio wave 
propagation winter season. *

*The approximate 11000- 30000 kHz frequency range closes sooner due to 
less sun light illuminating**the ionosphere than in the northern 
hemisphere. But the maximum usable frequency (MUF) is higher than in the 
northern hemisphere as the F layer of the ionosphere is lower in height 
and the ions more concentrated.*

*The approximately 3000-10000 kHz frequency range often stays open for 
DX all throughout the day due to a weaker D layer and therefore less RF 
signal absorption.*

*A weaker and shorter sporadic E (Es) season occurs during winter time.***

**

*SOUTHERN HEMISPHERE HIGH FREQUENCY (HF) RADIO WAVE PROPAGATION FORECAST 
**w***g*-*

**

*3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S3-4 
at day,

6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+15 at night and
S5-8 at day,

13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 
at night and S5-7 at day,

21000-21850 kHz- S0 at night and S1-2 at day,

24890-24990, 25600-26100 kHz- S0 at night and S1 at day,

*

*28000-29700 kHz- S0 at night and S0 at day.*

**

*---------------------------------------------------------------------------------------------------------------------*

**

*GLOBAL MEDIUM FREQUENCY (MF) (300-3000 KHZ) RADIO WAVE PROPAGATION 
CONDITIONS EXPECTED-*

**

*Received RF signal strength scale-*

*Very Good- +1 over S9 or greater*

*Good- S7-9*

*Fair- S4-6*

*Poor- S1-3*

*Very Poor- S0*

**

**

*FORECASTED NORTHERN HEMISPHERE SHORT PATH-*

*-East <-> West To 1100 Mi /1800 km *

*S7-8*

**North <-> South To 1100 Mi /1800 km*

*S8-9*

*+South <-> North To 1100 Mi /1800 km*

*S6-7*

*
**FORECASTED SOUTHERN HEMISPHERE SHORT PATH-*

*-East <-> West To 1100 Mi / 1800 km*

*S7-8*

**South <-> North To 1100 Mi /1800 km*

*S8-9*

*+North <-> South To 1100 Mi / 1800 km*

*S6-7*

*FORECASTED GREAT CIRCLE LONG OR SKEWED PATH- *

*Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans 
Pacific and cross Equatorial propagation conditions in**excess of 
approximately 3200 mi / 5200 km-*

*High Latitude*

*S6-7*

*Mid Latitude*

*S8-9*

*Low latitude*

*S5-6*

**

*FORECASTED GREAT CIRCLE LONG OR SKEWED PATH- *

*Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans 
Pacific and cross Equatorial propagation conditions in**excess of 
approximately 3200 mi / 5200 km-*

*High Latitude*

*S6-7*

*Mid Latitude*

*S8-9*

*Low latitude*

*S5-6*

**

**

*Received RF signal strength scale-*

*Very Good- +1 over S9 or greater*

*Good- S7-9*

*Fair- S4-6*

*Poor- S1-3*

*Very Poor- S0*

**

*This HF-MF Radio wave propagation forecast is produced based on the 
SIGINT_CAP HF-MF radio wave propagation prediction software. X and O ray 
tracing is included.*

*I wrote it beginning in the late 1980???s and continue to refine it in 2019.*

*But I???m sorry to say that it still can???t be distributed to the general 
public.*

*It does outperform VOA CAP and Prop Lab.*

**

*I do check the actual band conditions at my location in the USA and 
tweak the forecast manually where and when necessary.*

**

*I also check global HF-MF radio wave propagation conditions via remoted 
radio*

*receivers on every continent of the globe and tweak the forecast 
manually if*

*and when necessary.*

**

*And last but not least I look at ionsonde stations on every continent 
of the*

*globe.*

**

*The hamateur radio JT65A mode RF signal levels received are based on 5 
watts*

*and ?? wave dipole up at 40 feet.*

**

*The hamateur radio PSK31 mode RF signal levels received are based on 25*

*watts and ?? wave dipole up at 40 feet.*

**

*The hamateur radio CW mode RF signal levels received are based on 50 watts*

*and ?? wave dipole up at 40 feet.*

**

*The hamateur radio SSB RF mode signal levels received are based on 100 
watts*

*and ?? wave dipole up at 40 feet.*

**

*The HF shortwave broadcast band AM Mode RF signal levels are based on*

*100,000 watts (100 kw) and a typical high gain VOA type curtain array*

*antenna.*

**

*The MF broadcast band AM Mode RF signal levels are based on 50,000 
watts (50 kw) and an omnidirectional vertical antenna.*

**

*Please keep in mind that this is a relatively simplified HF-MF radio wave*

*propagation forecast, so as to keep it easily understandable and 
applicable*

*by the average radio enthusiast.*

**

*Standard Disclaimer-*

**

*Note! I use error prone RAW public domain data from the NOAA Space*

*Environment Center, other U.S. government entities and educational*

*institutions, to produce this daily HF-MF radio wave propagation*

*forecast. This data is gathered and made public by the U.S. Government 
using*

*taxpayer $$$ (including mine).*

**

*However this daily HF-MF propagation forecast that I produce from the RAW*

*public domain data is my personal intellectual property. Therefore this*

*daily HF-MF radio wave propagation forecast contained herein is 
copyrighted ??*

*1988-2019 by Thomas F. Giella, W4HM.*

**

*Feel free without prior permission to redistribute this daily HF-MF 
radio wave*

*propagation forecast, as long as you redistribute it in its entirety and*

*give me credit for it.*

**

*Also HF-MF radio wave propagation forecasting is still an inexact*

*science and therefore also an art. The forecasts are not official but for*

*educational and hobby related purposes only and are subject to human error*

*and acts of God, therefore no guarantee or warranty implied.*

**