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 : 22/02/2026 11:54:39 UTC
Il y a actuellement 9 message(s) (dont 4 alerte(s) et 8 message(s) encore actif(s) au SWPC)
ALERT : Type II Radio Emission
18/02/2026 04:52:00 UTC > DétailsImpact terrestre : 23/02/2026 18:34:00 UTC
Space Weather Message Code: ALTTP2
Serial Number: 1467
Issue Time: 2026 Feb 18 0452 UTC
ALERT: Type II Radio Emission
Begin Time: 2026 Feb 18 0431 UTC
Estimated Velocity: 310 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.
FermerWARNING : Geomagnetic K-index of 4 expected
21/02/2026 22:30:00 UTC > Détailsn/a
Space Weather Message Code: WARK04
Serial Number: 5265
Issue Time: 2026 Feb 21 2230 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2026 Feb 21 2230 UTC
Valid To: 2026 Feb 22 1200 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.
FermerALERT : Geomagnetic K-index of 4
21/02/2026 22:43:00 UTC > Détailsn/a
Space Weather Message Code: ALTK04
Serial Number: 2634
Issue Time: 2026 Feb 21 2243 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.
FermerWARNING : Geomagnetic K-index of 5 expected
22/02/2026 04:25:00 UTC > Détailsn/a
Space Weather Message Code: WARK05
Serial Number: 2196
Issue Time: 2026 Feb 22 0425 UTC
WARNING: Geomagnetic K-index of 5 expected
Valid From: 2026 Feb 22 0425 UTC
Valid To: 2026 Feb 22 1200 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.
FermerALERT : Geomagnetic K-index of 5
22/02/2026 05:03:00 UTC > Détailsn/a
Space Weather Message Code: ALTK05
Serial Number: 1967
Issue Time: 2026 Feb 22 0503 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.
FermerALERT : Geomagnetic K-index of 5
22/02/2026 07:40:00 UTC > Détailsn/a
Space Weather Message Code: ALTK05
Serial Number: 1968
Issue Time: 2026 Feb 22 0740 UTC
ALERT: Geomagnetic K-index of 5
Synoptic Period: 0600-0900 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.
FermerWARNING : EXTENDED Geomagnetic K-index of 4 expected
22/02/2026 08:00:00 UTC > Détailsn/a
Space Weather Message Code: WARK04
Serial Number: 5266
Issue Time: 2026 Feb 22 0800 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 5265
Valid From: 2026 Feb 21 2230 UTC
Now Valid Until: 2026 Feb 22 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.
FermerWARNING : EXTENDED Geomagnetic K-index of 5 expected
22/02/2026 08:00:00 UTC > Détailsn/a
Space Weather Message Code: WARK05
Serial Number: 2197
Issue Time: 2026 Feb 22 0800 UTC
EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2196
Valid From: 2026 Feb 22 0425 UTC
Now Valid Until: 2026 Feb 22 1800 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.
FermerWARNING : Geomagnetic K-Index of 6 expected
22/02/2026 08:00:00 UTC > Détailsn/a
Space Weather Message Code: WARK06
Serial Number: 642
Issue Time: 2026 Feb 22 0800 UTC
WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2026 Feb 22 0800 UTC
Valid To: 2026 Feb 22 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
G1
n/a
R0
HF Bands Noise Level
S4-S6
Indices bruts
SFI
107
SSN
11
Ap
24
Kp
5
Kp Lat.
56,3°
X-Ray (HAF)
B3,1
Protons E>10 MeV
0,18
Electrons >2MeV
152,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
694,8
Proton Density (p/cc)
2,7
Ion Temperature (°K)
280 000,0
IMF Bt (nT)
10,1
IMF Bz (nT)
5,2
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-78928 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-78928 min.
Data source
NOAA SWPC
Mise à jour des indices : 22/02/2026 11:53:39 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 »…)
