Check out the ACE-HF propagation software - the latest is version 2.05. ACE-HF is propagation forecasting and modeling for Amateur Radio as well as for Shortwave radio Listening and general HF operation. This software is even used by the military and other clients around the world. This software is developed and maintained by the same engineers that keep VOACAP up-to-date. As a result, this software is the most accurate user interface integrated with VOACAP. CHECK IT OUT, TODAY. This software is the most accurate modeling software available, and is endorsed by NW7US. Read the details to find out why.
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This page was rendered on 27-Jul-24 1417 UTC.
This page was first created as HFRadio.org in the mid 1990s, and morphed here in 1998, by Tomas David Hood (NW7US)
Current Sunspot Cycle 25 Activity ~ Space Weather ~ Shortwave Radio Propagation
Map, Above: Conditions in the D region of the ionosphere have a dramatic effect on high frequency (HF) communications and low frequency (LF) navigation systems. The global D Region Absorption Predictions (D-RAP) depicts the D region at high latitudes where it is driven by particles as well as low latitudes, where photons cause the prompt changes.
Note: At times, images may appear broken or missing, when SDO is working on the AIA/HMI instruments.
Planetary A-index (Ap): 23
| Planetary K-index (Kp): 4.33
Solar Wind: 421 km/s at 1.0 protons/cm3, Bz is 2.0 nT
(Jul 27, 2024 at 1404 UT)
X-ray Solar Flares:
6h hi [M4.2][0221Z 07/27] 24h hi [M4.2][0221Z 07/27]
What is the difference between the CB and Amateur Radio Services, in the USA? Here are some thoughts on the portrayal of the Amateur Radio Service by the Hit TV Series, NCIS, and a clarification of the difference between CB radio and ham radio.
(Skip to timecode 1:33 to bypass the introductory chat and talk about the headset microphone.)
Here is a video introduction to shortwave / HF amateur radio -- what is it that we amateur radio oprators listen to? If you have not yet been introduced to this world, this is a very basic introduction.
If you are using software utilities such as Ace-HF, that require a "smoothed" sunspot number
(Referred to as the SSN), or, the smoothed 10.7-cm Radio Flux Index,
use the following predicted values in this following table:
Predicted SMOOTHED Sunspot Number And Radio Flux Values
With Expected Ranges
YR/MO
Smoothed Sunspot Number
Predicted/High/Low
Smoothed 10.7 cm Radio Flux
Predicted/High/Low
To understand more about the Maximum Usable Frequencies, and related
science, please read the MUF Basics Page.
Global HF Propagation Conditions
Global HF Propagation Conditions for 0400Z on 05 May, 2021
High Latitude: Normal
Middle Latitude: Normal
Low Latitude: Normal
At 0805 UTC, on 9 August 2011, a strong magnitude X6.9 X-ray flare -- the strongest yet in this current solar cycle (Cycle 24) -- erupted on the northwestern solar limb. Here is a HD Movie of the event:
Videos of Interest - Space Weather, Solar Dynamics Observatory, STEREO, and more... from the NW7US YouTube Channel. (Click on the small image to launch the video...)
Video: Voyager Finds Magnetic Foam at Solar Systems Edge
Video: Zoom View of Prominence Eruption and X-Ray Flare - M2.5 Magnitude - June 7 2011
Video: X-Ray Flare, Coronal Mass Ejection, Proton Storm - M2.5 Magnitude - June 7 2011 (Close-up of the video, above)
Video: Stunning Close-up View of M3 X-Ray Flare 24 February 2011
Video: On How NCIS TV Show Maligned Amateur Radio Service (Full UHD Version)
What's the difference between CB and amateur (ham) radio?
Video: June 2011 20-meter (14-Mhz) JT65A Coverage Map of NW7US Radio Signal
The NW7US Current Sunspot and Geophysical Activity Report
The observations, prognastications, and comments by NW7US
NW7US is Tomas David Hood, Propagation and Space Weather Columnist
for CQ Communications
More about Background X-rays
The hard X-ray energy present from the wavelengths of 1 to 8 Angstroms provide the most effective ionizing energy throughout all of the ionospheric layers in our atmosphere. The GEOS satellites measure these wavelengths and the resulting measurements are reported as the "background X-ray level" throughout the day. A daily average is reported, as well.
Just like X-ray flares, the background hard X-ray level is measured in watts per square meter (W/m2), reported using the categories, A, B, C, M, and X. These letters are multipliers; each class has a peak flux ten times greater than the preceding one. Within a class there is a linear scale from 1 to 9.
If one records the daily background X-ray levels for the course of a sunspot cycle, one would discover that the background X-ray levels remained at the A class level during the sunspot cycle minumum. During the rise and fall of a solar cycle, the background X-ray energy levels remained mostly in the B range. During peak solar cycle periods, the background energy reached the C and sometimes even M levels.
Armed with this information, can we discover any clues as to the current status of Sunspot Cycle 24? Below is a graph plotting the background hard X-ray energy reported by the GEOS satellites since the end of Sunspot Cycle 22. Clearly, we see a noticeable rise in Cycle 24 activity. We're seeing the energy mostly in the B level more often, supporting the view that Cycle 24 is alive and moving along toward an eventual sunspot cycle peak in several years.
Overall, the monthly average background 'hard' X-ray level is rising (as seen by the following plot), showing a change from deep solar cycle minimum. We are certainly in the rising phase of Sunspot Cycle 24. While it has been a slow up-tick over the last eighteen months, I expect to see a more rapid rise during mid to late 2011.
Highlights of Solar and Geomagnetic Activity
Covering the period: 15 - 21 July 2024
Solar activity was at moderate to high levels. High levels were observed on 16 and 17 Jul due to an X1.9/1B flare at 16/1326 UTC from Region 3738 (S09, L=213, class/area Fkc/1140 on 14 Jul) and an M5.0/2b flare at 17/0639 UTC from Region 3743 (S08, L=162, class/area Dai/220 on 13 Jul). The X1 flare had accompanying Type II (398 km/s) and Type IV radio bursts, a Castelli U radio signature, as well as a CME of the W limb that was not Earth-directed. Region 3753 (N12, L=170, class/area Dai/100 on 16 Jul) and 3744 (N16, L=144, class/area Dso/180 on 12 Jul) produced a pair of M1 flares at 16/2124 UTC and 16/2206 UTC. Two associated partial halo CMEs were observed after 16/2312 UTC. Modelling of the pair indicated an arrival beginning at midday on 20 Jul followed by a secondary arrival early on 21 Jul. At 21/1610 UTC, a disappearing solar filament was observed in the vicinity of Region 3757 (N18, L=061, class/area Hax/060 on 17 Jul). An associated halo CME was observed at 21/1648 UTC. Initial analysis indicated an arrival on 24 Jul. Further analysis is in progress at the time of this writing.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels.
Geomagnetic field activity ranged from quiet to unsettled levels. Weak transient activity was evident on 15-16 Jul and possibly 19-20 Jul, however weak solar wind speeds in the 300-400 km/s range as well as a predominant northward Bz component led to only isolated unsettled periods on 15-16 Jul. Quiet conditions prevailed through 21 Jul.
Monthly and smoothed sunspot number - The monthly mean sunspot number (blue) and 13-month smoothed monthly sunspot number (red) for the last five cycles. You can see that this current cycle, Cycle 24, is a weak cycle, compared to the last few.
(Click to see actual size)
Daily and monthly sunspot number (last 13 years)
Daily sunspot number (yellow), monthly mean sunspot number (blue), smoothed monthly sunspot number (red) for the last 13 years and 12-month ahead predictions of the monthly smoothed sunspot number:
SC (red dots) : prediction method based on an interpolation of Waldmeier's standard curves; It is only based on the sunspot number series.
CM (red dashes) : method (from K. Denkmayr and P. Cugnon) combining a regression technique applied to the sunspot number series with the aa geomagnetic index used as a precursor (improved predictions during the minimum phase between solar cycles).
(Click to see actual size)
What is 'Space Weather'? Click on these two information slides to view them in full size:
View of numbered sunspot regions and plages (if any)
Source: http://www.solarmonitor.org/.
(Click for large view)
Active sunspot regions, and plages, identified by SIDC
STEREO IMAGES
What is coming
Current View
What was...
Real Time Solor Wind and Aurora:
On 2024 Jul 27 1412Z: Bz: 1.9 nT
Bx: -6.0 nT | By: 4.0 nT | Total: 7.4 nT
Most recent satellite polar pass:
Centered on // : UTC Aurora Activity Level was at UTC
visit noaa for latest.
This is a video of the simulation from May 27-28, 2011, showing
the Geomagnetic disturbance caused by the solar wind
Three Day Forecast of Solar and Geomagnetic Activity
(as of 2200Z on 07 Dec 2014)
Solar Forecast:
Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (08 Dec, 09 Dec, 10 Dec).
Geomagnetic Forecast:
The geomagnetic field is expected to be at quiet to minor storm levels on day one (08 Dec), quiet to active levels on day two (09 Dec) and quiet levels on day three (10 Dec).
Forecast of Solar and Geomagnetic Activity
22 July - 17 August 2024
Solar activity is expected to continue at moderate levels with M-class flares (R1-R2, Minor-Moderate) levels likely and a slight chance for X-class (R3, Strong) through 27 Jul as Regions 3751 (S08, L=092, class/area Ekc/410 on 19 Jul) and 3761 (S10, L=081, class/area Dki/300 on 21 Jul) rotate across the visible disk. Low to moderate levels are likely from 28 Jul through 17 Aug.
There is a slight chance for a greater than 10 MeV proton event exceeding the S1 (Minor) levels through 29 Jul due to the flare potential of Regions 3751 and 3761.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to continue at normal to moderate levels.
Geomagnetic field activity is expected to be at mostly quiet levels through 17 Aug barring any inbound CME activity. A potential for G1-G2 (Minor-Moderate) levels is likely for 24 Jul due to the arrival of the 21 Jul CME, however analysis is still in progress.
Data and images courtesy of IPS Australia, NOAA, NASA, SWPC, SIDC
Layout, analysis, commentary, and certain forecasts and content is Copyright, 2022, Tomas David Hood (NW7US), all rights reserved.
No part, except for the space weather 'banners', may be copied without express permission.