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 04-Apr-23 0301 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): 15
| Planetary K-index (Kp):
Solar Wind: 499 km/s at 11.0 protons/cm3, Bz is -1.0 nT
(Apr 04, 2023 at 0246 UT)
X-ray Solar Flares:
6h hi [C2.8][2349Z 04/03] 24h hi [C2.8][2349Z 04/03]
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: 27 March - 02 April 2023
Solar activity reached high levels due to significant flaring from Region 3256 (S22, L=001, class/area, Fho/340 on 28 Mar). Region 3256 produced: an X1.2 flare (R3-Strong) at 29/0233 UTC; an M5.4/1f flare (R2-Moderate) at 30/0737 UTC; an M1.2/1f flare (R1-Minor) at 29/1407 UTC; and an M1.1/1n flare (R1-Minor) at 29/2347 UTC. Region 3257 (S27, L=350, class/area, Hax/190 on 23 Mar) produced a C9.7/1f flare at 31/2057 UTC. Region 3270 (S23, L=237, class/area, Dao/80 on 02 Apr) provided several low level C-class flares late in the highlight period after its rapid development on 02 Apr.
No proton events were observed at geosynchronous orbit, however, the greater than 10 MeV proton flux became slightly elevated following the M5.4/1f flare from Region 3256 mentioned above. A peak value of 0.61 pfu was observed at the GOES-16 spacecraft at 30/1015 UTC, remaining well below the 10 pfu alert threshhold (S1-Minor).
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels throughout the reporting period (27 Mar - 02 Apr).
Geomagnetic field activity reached G1 (Minor) geomagnetic storm levels on 31 Mar, with active levels on 30 Mar and 01-02 Apr, due to recurrent, negative-polarity CH HSS influence. Quiet to unsettled geomagnetic conditions were reported throughout the remainder of the reporting period.
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 2023 Apr 04 0159Z: Bz: -0.9 nT
Bx: -1.1 nT | By: -5.8 nT | Total: 6.0 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
Outlook: (valid from 1230UT, 03 Apr 2023 until 05 Apr 2023)
Solar Flares: Quiet conditions (<50% probability of C-class flares) Geo-Disturbance: Quiet (A<20 and K<4) Solar Proton Event: Quiet
Comment from the SIDC (RWC Belgium): The solar flaring activity is low with several low C-class flares reported during the last 24 hours. The largest reported flare was GOES C3.4 which peaked at 23:13 UT on April 02. The majority of the flaring activity, as well as the strongest reported flare, was originating from the NOAA AR 3270 which is still increasing in the sunspot area and the complexity of its photosperic magnetic field configuration (presently classified as beta). In the coming hours we expect C-class flares and possible, but not very probable isolated M-class flares. The flaring activity is expected to originate mostly from the NOAA AR 3270 and the non-numbered active region which is presently rotating on the visible side of the Sun (situated at the latitudes of about S30).
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
03 April - 29 April 2023
Solar activity is expected to be at very low levels, with a chance for C-class flare activity, until the return of Region 3256 on 12 Apr. Region 3256 was responsible for X-class and M-class flare activity (R1-R3) on its previous transit across the visible solar disk.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 03-06 and 23-29 Apr. Moderate levels are expected for the remainder of the outlook period.
Geomagnetic field activity is expected to reach G1-Minor storm levels on 20 and 27 Apr, active levels on 05, 10-11, 16, 18, 21, 26, 28-29 Apr due to influence from recurrent CH HSSs. Quiet to unsettled conditions are anticipated for the remainder of the outlook period.
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.