Indices solaires, géomagnétiques et alertes HF

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 : 15/02/2026 11:20:39 UTC
Il y a actuellement 9 message(s) (dont 3 alerte(s) et 9 message(s) encore actif(s) au SWPC)
WARNING : Geomagnetic K-index of 4 expected   14/02/2026 19:59:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5255 Issue Time: 2026 Feb 14 1959 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2026 Feb 14 2000 UTC Valid To: 2026 Feb 15 0300 UTC Warning Condition: Onset 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
ALERT : Geomagnetic K-index of 4   14/02/2026 21:33:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK04 Serial Number: 2632 Issue Time: 2026 Feb 14 2133 UTC ALERT: Geomagnetic K-index of 4 Synoptic Period: 2100-2400 UTC Active Warning: Yes 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 4 expected   14/02/2026 21:35:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5256 Issue Time: 2026 Feb 14 2135 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5255 Valid From: 2026 Feb 14 2000 UTC Now Valid Until: 2026 Feb 15 0900 UTC Warning Condition: Onset 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   14/02/2026 21:35:00 UTC   > Détails
n/a
Space Weather Message Code: WARK05 Serial Number: 2190 Issue Time: 2026 Feb 14 2135 UTC WARNING: Geomagnetic K-index of 5 expected Valid From: 2026 Feb 14 2135 UTC Valid To: 2026 Feb 15 0600 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   15/02/2026 02:13:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1964 Issue Time: 2026 Feb 15 0213 UTC ALERT: Geomagnetic K-index of 5 Synoptic Period: 0000-0300 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   15/02/2026 04:35:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1965 Issue Time: 2026 Feb 15 0435 UTC ALERT: Geomagnetic K-index of 5 Synoptic Period: 0300-0600 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   15/02/2026 05:14:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5257 Issue Time: 2026 Feb 15 0514 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5256 Valid From: 2026 Feb 14 2000 UTC Now Valid Until: 2026 Feb 15 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 : EXTENDED Geomagnetic K-index of 5 expected   15/02/2026 05:14:00 UTC   > Détails
n/a
Space Weather Message Code: WARK05 Serial Number: 2191 Issue Time: 2026 Feb 15 0514 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 2190 Valid From: 2026 Feb 14 2135 UTC Now Valid Until: 2026 Feb 15 2100 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   15/02/2026 05:14:00 UTC   > Détails
n/a
Space Weather Message Code: WARK06 Serial Number: 639 Issue Time: 2026 Feb 15 0514 UTC WARNING: Geomagnetic K-Index of 6 expected Valid From: 2026 Feb 15 0515 UTC Valid To: 2026 Feb 15 1500 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

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
S2-S3
Indices bruts
SFI
114
SSN
60
Ap
23
Kp
3
Kp Lat.
60,4°
X-Ray (HAF)
B4,1 (1,15 MHz)
Protons E>10 MeV
0,20
Electrons >2MeV
198,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
679,7
Proton Density (p/cc)
2,0
Ion Temperature (°K)
414 000,0
IMF Bt (nT)
8,7
IMF Bz (nT)
6,4
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-68814 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-68814 min.
Data source
NOAA SWPC
Mise à jour des indices : 15/02/2026 11:19:39 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 »…)