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 23-Mar-23 1355 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): 17
| Planetary K-index (Kp):
Solar Wind: 484 km/s at 55.0 protons/cm3, Bz is -2.0 nT
(Mar 23, 2023 at 1343 UT)
X-ray Solar Flares:
6h hi [C2.5][1909Z 03/22] 24h hi [C2.5][1909Z 03/22]
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: 13 - 19 March 2023
Solar activity reached moderate levels on 17 Mar due to an M1/Sn flare (R1 - Minor) at 17/1507 UTC from Region 3247 (S24, L=162, class/area=Cao/100 on 08 Mar). The other 17 numbered active regions on the visible disk only produced low levels of solar activity during the summary period. Other activity included many filament eruptions but only a DSF on ~17/0930 UTC, centered near S40W38, was modeled and thought to have an Earth-directed component. Model output suggested anticipated onset of the CME to be late on 20 Mar to early on 21 Mar. Lastly, a Type IV radio sweep was observed in conjunction with an impulsive C9/1n 18/0716 UTC flare from Region 3256 (S22, L=004, class/area=Eko/270 on 19 Mar).
The greater than 10 MeV proton flux reached S1 (Minor) levels on 13 Mar. The enhancement was associated with a full-halo CME first observed in SOHO/LASCO C2 imagery beginning near 13/0336 UTC. The energetic event was determined to be associated with activity on the far-side of the Sun but still was able to produce significant enhancements in relativistic proton flux on the GOES-16 satellite. S1 conditions were reached again on 14 Mar, with an additional enhancement associated with a shock ahead of a CME that would arrive on 15 Mar that would increase 10 MeV protons back above the S1 threshold to an eventual peak flux of 22 pfu at 15/0425 UTC. After shock passage, the >10 MeV proton flux quickly decreased, with the last observation above the S1 threshold observed at 15/0530 UTC.
The greater than 2 MeV electron flux at geosynchronous orbit was moderate levels over the summary period.
Geomagnetic field activity range from quiet to G2 (Moderate) geomagnetic storm levels. G2 conditions were observed on 15 Mar in response to influence from a CMEs that left the Sun over 11 and 12 Mar. Total magnetic field strength (Bt) increased from 8 nT 18 nT during the shock at 15/0347 UTC. With the shock, wind speeds increased from ~425 km/s to ~525 km/s. Bt reached a peak of 24-25 nT shortly after and solar wind speeds were recorded at ~570 km/s before both speeds and Bt underwent a gradual decline. Weaker activity, also associated with transient activity produced active conditions on 14 Mar and 16 Mar. Mostly quiet to unsettled conditions were observed on 17-19 Mar and only quiet conditions were observed on 13 Mar.
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 Mar 23 1348Z: Bz: 2.1 nT
Bx: 6.5 nT | By: 20.9 nT | Total: 22.0 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, 22 Mar 2023 until 24 Mar 2023)
22 Mar 2023 10.7-cm Flux: 150 / Ap: 018
23 Mar 2023 10.7-cm Flux: 150 / Ap: 028
24 Mar 2023 10.7-cm Flux: 150 / Ap: 014
Forecast:
Solar Flares: C-class flares expected, (probability >=50%) Geo-Disturbance: Minor storm expected (A>=30 or K=5) Solar Proton Event: Quiet
Comment from the SIDC (RWC Belgium): Solar flaring activity was at low levels in the past 24 hours. Multiple low C-class flares were produced by NOAA AR 3257 (beta-delta), NOAA AR 3259 (beta), NOAA AR 3260 (beta) and the newly numbered active region NOAA 3261 (beta). A new unnumbered active region is rotating from the southeast limb and might contribute to the C-class flaring activity over the next 24h. The solar flaring activity is expected to remain at low levels over the next 24 hours with small chances for isolated M-class flaring.
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
20 March - 15 April 2023
Solar activity is expected to be at low levels with a chance for R1-R2 (Minor-Moderate) events. This is due to the flare potential of regions both currently on the visible disk and significant regions expected to return to the visible disk from the far-side of the Sun over the outlook period.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to range from moderate to high levels. High levels are likely on 26-29 Mar and 31 Mar - 06 Apr due to multiple, recurrent CH HSSs. The remainder of the outlook period is likely to be at normal to moderate levels.
Geomagnetic field activity is expected to be at quiet to G2 (Moderate) geomagnetic storm levels. G2 conditions are likely on 25 Mar; G1 (Minor) conditions are likely on 26 Mar and 30-31 Mar; active conditions are likely on 20-21 Mar, 01-02 Apr and 10-11 Apr; unsettled conditions are likely on 24 Mar, 27-28 Mar, 03-04 Apr, 12 Apr and 14-15 Apr. With the exception of 20-21 Mar, which is expected to include possible transient influence as well, all anticipated enhancements in geomagnetic conditions are in response to multiple, recurrent CH HSSs. The remainder of the outlook period is expected to be at mostly quiet levels.
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.