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 : 14/10/2025 02:35:31 UTC
Il y a actuellement 7 message(s) (dont 5 alerte(s) et 7 message(s) encore actif(s) au SWPC)
ALERT : Geomagnetic K-index of 5   13/10/2025 02:57:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1880 Issue Time: 2025 Oct 13 0257 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 : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu   13/10/2025 03:02:00 UTC   > Détails
n/a
Space Weather Message Code: ALTEF3 Serial Number: 3545 Issue Time: 2025 Oct 13 0302 UTC CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3544 Begin Time: 2025 Oct 01 1325 UTC Yesterday Maximum 2MeV Flux: 1707 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. Fermer
ALERT : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu   13/10/2025 05:07:00 UTC   > Détails
n/a
Space Weather Message Code: ALTEF3 Serial Number: 3546 Issue Time: 2025 Oct 13 0507 UTC CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3545 Begin Time: 2025 Oct 01 1325 UTC Yesterday Maximum 2MeV Flux: 1707 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. Fermer
ALERT : Geomagnetic K-index of 5   13/10/2025 05:30:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK05 Serial Number: 1881 Issue Time: 2025 Oct 13 0530 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
ALERT : Type II Radio Emission   13/10/2025 17:26:00 UTC   > Détails
Impact terrestre : 16/10/2025 13:57:00 UTC
Space Weather Message Code: ALTTP2 Serial Number: 1433 Issue Time: 2025 Oct 13 1726 UTC ALERT: Type II Radio Emission Begin Time: 2025 Oct 13 1303 UTC Estimated Velocity: 570 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   13/10/2025 17:54:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5108 Issue Time: 2025 Oct 13 1754 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5107 Valid From: 2025 Oct 11 0502 UTC Now Valid Until: 2025 Oct 14 0300 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
WATCH : Geomagnetic Storm Category G1 Predicted   13/10/2025 21:09:00 UTC   > Détails
n/a
Space Weather Message Code: WATA20 Serial Number: 1070 Issue Time: 2025 Oct 13 2109 UTC WATCH: Geomagnetic Storm Category G1 Predicted Highest Storm Level Predicted by Day: Oct 14: None (Below G1) Oct 15: None (Below G1) Oct 16: G1 (Minor) THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT Comment: G1 (Minor) geomagnetic storming is likely on 16 Oct as CMEs that left the Sun on 11-12 Oct arrive and impact the near-Earth environment. 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

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
143
SSN
122
Ap
23
Kp
3
Kp Lat.
60,4°
X-Ray (HAF)
C1,7 (7,30 MHz)
Protons E>10 MeV
0,19
Electrons >2MeV
1 160,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
720,8
Proton Density (p/cc)
1,6
Ion Temperature (°K)
240 000,0
IMF Bt (nT)
3,7
IMF Bz (nT)
2,9
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=12)
Impact as low as
62,5°
Expected in
-9 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=12)
Impact as low as
62,5°
Expected in
-9 min.
Data source
NOAA SWPC
Mise à jour des indices : 14/10/2025 02:34:31 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 »…)