Indices solaires, géomagnétiques et alertes HF

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Cette page présente les indices géomagnétiques et solaires, ainsi que les alertes du Space Weather Prediction Center (NOAA – USA) en vigueur actuellement.
Pour plus d’information sur ces alertes, visitez : http://www.swpc.noaa.gov/noaa-scales-explanation.

Messages émis par le NOAA/Space Weather Prediction Center
Mise à jour : 12/01/2026 10:18:55 UTC
Il y a actuellement 11 message(s) (dont 5 alerte(s) et 9 message(s) encore actif(s) au SWPC)
ALERT : Type II Radio Emission   09/01/2026 10:24:00 UTC   > Détails
Impact terrestre : 17/01/2026 22:14:00 UTC
Space Weather Message Code: ALTTP2 Serial Number: 1464 Issue Time: 2026 Jan 09 1024 UTC ALERT: Type II Radio Emission Begin Time: 2026 Jan 09 0932 UTC Estimated Velocity: 203 km/s Comment: Current imagery does not suggest any on-disk source at this time. Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event. Fermer
ALERT : Type II Radio Emission   09/01/2026 15:17:00 UTC   > Détails
Impact terrestre : 18/01/2026 04:31:00 UTC
Space Weather Message Code: ALTTP2 Serial Number: 1465 Issue Time: 2026 Jan 09 1517 UTC ALERT: Type II Radio Emission Begin Time: 2026 Jan 09 1244 UTC Estimated Velocity: 200 km/s Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event. Fermer
WARNING : EXTENDED Geomagnetic K-index of 4 expected   11/01/2026 11:06:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5216 Issue Time: 2026 Jan 11 1106 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5215 Valid From: 2026 Jan 10 0732 UTC Now Valid Until: 2026 Jan 11 2359 UTC Warning Condition: Persistence www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Fermer
WARNING : Geomagnetic K-index of 5 expected   11/01/2026 14:19:00 UTC   > Détails
n/a
Space Weather Message Code: WARK05 Serial Number: 2169 Issue Time: 2026 Jan 11 1419 UTC WARNING: Geomagnetic K-index of 5 expected Valid From: 2026 Jan 11 1419 UTC Valid To: 2026 Jan 11 2100 UTC Warning Condition: Onset NOAA Scale: G1 - Minor www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Spacecraft - Minor impact on satellite operations possible. Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine. Fermer
ALERT : Geomagnetic K-index of 5   11/01/2026 14:39:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1940 Issue Time: 2026 Jan 11 1439 UTC ALERT: Geomagnetic K-index of 5 Synoptic Period: 1200-1500 UTC Active Warning: Yes NOAA Scale: G1 - Minor www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Spacecraft - Minor impact on satellite operations possible. Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine. Fermer
ALERT : Geomagnetic K-index of 5   11/01/2026 17:28:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1941 Issue Time: 2026 Jan 11 1728 UTC ALERT: Geomagnetic K-index of 5 Synoptic Period: 1500-1800 UTC Active Warning: Yes NOAA Scale: G1 - Minor www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Spacecraft - Minor impact on satellite operations possible. Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine. Fermer
ALERT : Geomagnetic K-index of 5   11/01/2026 19:09:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1942 Issue Time: 2026 Jan 11 1909 UTC ALERT: Geomagnetic K-index of 5 Synoptic Period: 1800-2100 UTC Active Warning: Yes NOAA Scale: G1 - Minor www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Spacecraft - Minor impact on satellite operations possible. Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine. Fermer
WARNING : EXTENDED Geomagnetic K-index of 4 expected   11/01/2026 19:19:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5217 Issue Time: 2026 Jan 11 1919 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5216 Valid From: 2026 Jan 10 0732 UTC Now Valid Until: 2026 Jan 12 1200 UTC Warning Condition: Persistence www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Fermer
WARNING : EXTENDED Geomagnetic K-index of 5 expected   11/01/2026 19:19:00 UTC   > Détails
n/a
Space Weather Message Code: WARK05 Serial Number: 2170 Issue Time: 2026 Jan 11 1919 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 2169 Valid From: 2026 Jan 11 1419 UTC Now Valid Until: 2026 Jan 12 0600 UTC Warning Condition: Persistence www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Spacecraft - Minor impact on satellite operations possible. Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine. Fermer
WARNING : Geomagnetic K-Index of 6 expected   11/01/2026 19:19:00 UTC   > Détails
n/a
Space Weather Message Code: WARK06 Serial Number: 632 Issue Time: 2026 Jan 11 1919 UTC WARNING: Geomagnetic K-Index of 6 expected Valid From: 2026 Jan 11 1917 UTC Valid To: 2026 Jan 12 0300 UTC Warning Condition: Onset NOAA Scale: G2 - Moderate www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms. Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible. Radio - HF (high frequency) radio propagation can fade at higher latitudes. Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state. Fermer
WARNING : EXTENDED Geomagnetic K-index of 4 expected   12/01/2026 09:02:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5218 Issue Time: 2026 Jan 12 0902 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5217 Valid From: 2026 Jan 10 0732 UTC Now Valid Until: 2026 Jan 12 2359 UTC Warning Condition: Persistence www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Fermer

Conditions HF, indices solaires et géomagnétiques et historique quotidien
La plupart de ces données sont mises à jour en temps réel.

Conditions HF
NOAA Scale Activity
G0
n/a
R0
HF Bands Noise Level
S3-S4
Indices bruts
SFI
108
SSN
84
Ap
31
Kp
4
Kp Lat.
58,3°
X-Ray (HAF)
C1,4 (6,49 MHz)
Protons E>10 MeV
0,14
Electrons >2MeV
486,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
523,8
Proton Density (p/cc)
0,7
Ion Temperature (°K)
53 400,0
IMF Bt (nT)
7,6
IMF Bz (nT)
-0,2
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-19791 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-19791 min.
Data source
NOAA SWPC
Mise à jour des indices : 12/01/2026 10:16:55 UTC
Historique des indices pour la journée

Cette page réunit de nombreux indices solaires et terrestres. Ces données sont issues des satellites défilants (TIROS n – NOAA), géostationnaires (GOES – NOAA), ainsi que des satellites SOHO (NASA/ESA) et SDO/EVE (NASA). Les données de flux solaire proviennent quant à elles de l’observatoire de Penticton (CA).
Certaines valeurs sont des moyennes calculées sur les 15 dernières minutes (Bt et Bz), le flux solaire est publié à 17:00, 21:00 et 23:00 (UTC). Les autres sont des valeurs en temps réel (ou presque).
Une juxtaposition des données historisées de cette page et de l’historique de réception de FAROS est disponible sur cette page.

Merci à Paul, N0NBH pour son aide et sa patience (son site est très intéressant : www.hamqsl.com)

Plus d’infos sur ces indices :
– NOAA Space Weather Scales – http://www.swpc.noaa.gov/NOAAscales
– NOAA Tips on viewing the Aurora – http://www.swpc.noaa.gov/products/aurora-30-minute-forecast

Références :
– HF Ionospheric Radio Signal Propagation (en) http://www.radio-electronics.com/info/propagation/ionospheric/hf-propagation-basics.php
– Glossaire du SWPC de la NOAA (en) : http://legacy-www.swpc.noaa.gov/info/glossary.html
– What the data means – Scott Bidstrup, W7RI (en) http://www.bidstrup.com/w7ri-hf-radio-propagation.htm
– Understanding HF Radio Propagation Forecasts, N0HR (en) : http://www.n0hr.com/radio_propagation.htm
– Ionosphere Properties and Behaviors – Marcel H. De Canck ON5AU, AntenneX n°110 / Juin 2006 (en) : www.antennex.com (site hors ligne, essayez la « wayback machine »…)
– Ham-Bands propagation properties – Marcel H. De Canck ON5AU, AntenneX n°142 / Février 2009 (en) : www.antennex.com (site hors ligne, essayez la « wayback machine »…)