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HF PROPAGATION - GLOBAL FORECAST :
Skip the Introductory Material and go straight to Current Conditions and the Forecast
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Make your own HF propagation forecast ?
Jump Directly to the SEC / Dept. of Commerce 27-Day Ap, Kp and 10.7cm Solar Index Forecast
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HF Propagation
A working definition of " NORMAL " operating conditions is narrowed down to be the conditions that one would derive for an average day without Solar or Geomagnetic Storms. The numeric data used in computation of propagation includes data from standard tables of F 10.7 cm Solar Flux and the Ap- Index. We do use other data to refine the term "Normal" . The terms " FAIR " and " POOR " are terms that are relative to the term " NORMAL ". The have not been assigned to any certain range of data at this time and they have no established logarithmic relationship ( ie. decibel value ) to " NORMAL ". All of these terms are in common use in High Frequency ( HF ) Propagation Forecasting circles and are accepted by most propagation forecasters.
"E10.7 is integrated extreme ultraviolet flux
from 1-105 nm"
Either "E" or "F" =Indices may be used to represent solar flux in equations asking for a solar index. The "E-Index" includes a number of factors not found in the "F-Index". We feel that the E-Index gives a better ionospheric profile than does the F-Index. The E-Index includes integrated value of solar irradiances over a wide range of wave lengths as opposed to a single isolated value for solar irradiance (F-Index)
The "45-Day AP and F10.7cm Flux Forecast" page is assembled by the U.S. Air
Force. The URL for this table is
http://www.sec.noaa.gov/ftpdir/latest/45DF.txt
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Current Conditions
Estimated Kp - Index published by NOAA
Each block is a 3-hour period in a UTC day. 8blocks/day
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We are at a low point in a 11 - year solar
cycle that will reach
solar minim in 2007.
RIGHT: Sunspot number progression in the current solar cycle ( Solar Cycle 23 ). The graph is published through the courtesy of the Space Environment Center (SEC), a division of NOAA.
WKHF LONG RANGE FORECAST FOR : 23 Nov through 19 Dec
Product: Weekly Highlights and Forecasts
:Issued: 2005 Nov 22 2154 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
# Product description and SEC contact on the Web
# http://www.sec.noaa.gov/weekly.html
#
# Weekly Highlights and Forecasts
Forecast of Solar and Geomagnetic Activity 23 November - 19 December 2005
Solar activity is expected to be at low to moderate levels through 25 November when Region 822 is due to rotate around the west limb.
Thereafter, very low to low activity is expected.
No greater than 10 MeV proton events are expected.
The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at high levels on 01 – 08 December.
The geomagnetic field is expected to range from quiet to minor storm
levels. Unsettled to active levels are possible on 10 December due
to recurrence.
Unsettled to minor storm levels are possible on 30
November – 01 December due to recurrent coronal hole high speed wind
streams. Otherwise, expect quiet to unsettled conditions.
GLOBAL FORECAST: For the UTC days : 17 Dec through 19 Dec 2005 (72-hour period)
HF radio wave propagation will remain "normal" in the Low, Middle, and Hight geomagnetic latitudes for the next 72-hours.
Web Site definition of " Normal "
A Break-Down by Latitude is listed below
10.7cm SF Ap-Index Kp-Index
The following table was reviewed and updated on 17 December 2005
:Product: 27-day Space Weather Outlook Table 27DO.txt :Issued: 2005 Dec 13 21:23 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Environment Center # Product description and SEC contact on the Web # http://www.sec.noaa.gov/wwire.html # # 27-day Space Weather Outlook Table # Issued 2005 Dec 06 # # UTC Radio Flux Planetary Largest # Date 10.7 cm A Index Kp Index 2005 Dec 14 90 5 2 2005 Dec 15 90 8 3 2005 Dec 16 90 8 3 2005 Dec 17 85 5 2 2005 Dec 18 85 5 2 2005 Dec 19 85 5 2 2005 Dec 20 85 5 2 2005 Dec 21 85 8 3 2005 Dec 22 80 10 3 2005 Dec 23 85 5 2 2005 Dec 24 90 3 1 2005 Dec 25 90 8 3 2005 Dec 26 90 5 2 2005 Dec 27 90 10 3 2005 Dec 28 95 15 3 2005 Dec 29 95 15 3 2005 Dec 30 95 10 3 2005 Dec 31 95 5 2 2006 Jan 01 95 5 2 2006 Jan 02 95 5 2 2006 Jan 03 95 5 2 2006 Jan 04 95 5 2 2006 Jan 05 90 8 3 2006 Jan 06 85 10 3 2006 Jan 07 85 20 4 2006 Jan 08 85 5 2 2006 Jan 09 85 5 2
SEC / Dept. of Commerce
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Go to Auroral Activity Page 1 (20.3 KB)
Go to Aurora Page 2 (10.2 KB)
Go to Aurora Activity Page 3 (7.4 KB)
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Low Latitudes ( 0 to 20 deg latitude ) : NORMAL - / NORMAL - / NORMAL -
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*Equatorial: NORMAL / NORMAL / NORMAL
IPS
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Middle Latitudes ( 20 to 60 deg latitude ): NORMAL / NORMAL / NORMAL
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High Latitudes ( 60 to : 90deg latitude ): NORMAL - / NORMAL - / FAIR -
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* This portion of the forecast frequently is courtesy of IPS Space Weather Services
All other forecasts originate independently with www.zseltvay.com . Raw data used in forecasting originates primarily from NOAA/SEC, U.S. Air Force, and IPS. Other data sources are frequently used.
The KC4COP Web Site forecast takes hours to prepare. We do not always have enough time during the day to prepare a high quality forecast - forecasts that often include how raw data is being used in the forecast and how events influences high frequency radio wave propagation. For that reason we are not able to always publish OUR forecast.
The foF2 forecast are made by KC4COP using multiple models (including a modified Costello Geomagnetic Activity Index model). Frequencies at 0, 12, and 23 hours and 45 minutes are computed separately based in part on estimated Kp values for the end of the standard 3-hour period for computing Kp. The Space Environment Center uses estimated Kp values computed for 15 minute periods in its Costello Geomagnetic Activity Index.
The F10.7cm - Solar Index and E10.7cm - Solar Index are used to represent solar activity. Readers using models that rely on the sunspot number can use the 6-hour effective sunspot number to derive the critical frequency or the frequency that will produce a 3 km bounce and hop signal .
The KC4COP method for estimating the Kp-Index for the end of the standard 3-hour period is based on solar wind activity and changes in the solar wind velocity over the 45-minute period leading up to the end of the 3-hour period. Verification of the Web Site data is about what one would expect out of a small operation. Official SEC / NOAA and U.S. Air Force values are published on the Web Site in very prominent places for those who want the "official word".
Critical Frequency Comparison of high frequency radio wave propagation forecasts from "official sources" as mentioned above - with propagation forecast by our own forecasters are usually quite close. We presently scan over 40 commercial radio stations in the lower portions of high frequency spectrum, monitor dx beacons, and look for QSOs on 20, 15, and 10 meters when beacons are not heard
The Costello Geomagnetic Activity Index is being used as a trial model for estimating the activity of the geomagnetic field by the Space Environment Center / National Oceanic and Atmospheric Administration.
Solar wind and particle data is obtained primarily from the U.S.'s " Advanced Composition Explorer (ACE) Satellite ". The ACE Satellite is owned and operated by NASA. Other agencies, such as NOAA, publish the ACE Satellite data and are often referenced as the primary source. This is not entirely correct. Raw data from other NASA satellites such as The Solar and Heliospheric Observatory (SOHO) Satellite also is used.
Full details of the ACE Satellite operations are given on the Web Site's ACE Satellite page
From NOAA, Space Environment Center, Dept. of Commerce, U.S. Air Force
72-Hour Forecast
When Earth passes through a high speed solar wind stream, the velocity of the solar wind dictates how much Earth's magnetic field ( EMF ) is disturbed. It is not only the speed of the solar wind but also the direction the EMF is distorted by the high speed solar wind stream that determines how badly HF propagation will decline.
Bz, ( the north - south component of the Interplanetary Magnetic Field ( IMF ) using the GSM system of coordinates ) is a measurement that indicates the direction of the solar wind is pushing on Earth's magnetic field. When the solar wind points northward ( Bz is express as a positive value ), the effect of the solar wind on HF radio wave propagation is "good" . A solar wind stream pointing in a southward direction ( negative Bz value ) is detrimental to propagation. The value of Bz and the solar wind speed are measured by the ACE satellite located at the L1 point in space.
We pay special attention to the F10 cm - Index and the Ap - Index in our forecast. The F10cm - Index represents solar intensity and the Ap - Index is a good indication of the geomagnetic state.
Space Environment Center (SEC) 27-Day Forecast for RADIO FLUX; Ap-Index; Kp-Index
Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
Complete Solar Weather and Geomagnetic Condition and 3-Day Forecast