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 : 26/02/2026 12:57:39 UTC
Il y a actuellement 7 message(s) (dont 3 alerte(s) et 6 message(s) encore actif(s) au SWPC)
ALERT : Type II Radio Emission
25/02/2026 07:28:00 UTC > DétailsImpact terrestre : 28/02/2026 04:43:00 UTC
Space Weather Message Code: ALTTP2
Serial Number: 1468
Issue Time: 2026 Feb 25 0728 UTC
ALERT: Type II Radio Emission
Begin Time: 2026 Feb 25 0653 UTC
Estimated Velocity: 595 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
25/02/2026 21:41:00 UTC > Détailsn/a
Space Weather Message Code: WARK04
Serial Number: 5273
Issue Time: 2026 Feb 25 2141 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2026 Feb 25 2140 UTC
Valid To: 2026 Feb 26 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.
FermerALERT : Geomagnetic K-index of 4
25/02/2026 21:47:00 UTC > Détailsn/a
Space Weather Message Code: ALTK04
Serial Number: 2636
Issue Time: 2026 Feb 25 2147 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 : EXTENDED Geomagnetic K-index of 4 expected
26/02/2026 01:08:00 UTC > Détailsn/a
Space Weather Message Code: WARK04
Serial Number: 5274
Issue Time: 2026 Feb 26 0108 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 5273
Valid From: 2026 Feb 25 2140 UTC
Now Valid Until: 2026 Feb 26 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.
FermerWARNING : Geomagnetic K-index of 5 expected
26/02/2026 01:10:00 UTC > Détailsn/a
Space Weather Message Code: WARK05
Serial Number: 2201
Issue Time: 2026 Feb 26 0110 UTC
WARNING: Geomagnetic K-index of 5 expected
Valid From: 2026 Feb 26 0109 UTC
Valid To: 2026 Feb 26 0900 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 : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu
26/02/2026 04:59:00 UTC > Détailsn/a
Space Weather Message Code: ALTEF3
Serial Number: 3635
Issue Time: 2026 Feb 26 0459 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3634
Begin Time: 2026 Feb 23 1045 UTC
Yesterday Maximum 2MeV Flux: 10494 pfu
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
FermerWARNING : EXTENDED Geomagnetic K-index of 4 expected
26/02/2026 11:55:00 UTC > Détailsn/a
Space Weather Message Code: WARK04
Serial Number: 5275
Issue Time: 2026 Feb 26 1155 UTC
EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 5274
Valid From: 2026 Feb 25 2140 UTC
Now Valid Until: 2026 Feb 26 1800 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
S2-S3
Indices bruts
SFI
121
SSN
25
Ap
19
Kp
3
Kp Lat.
60,4°
X-Ray (HAF)
B8,5 (4,31 MHz)
Protons E>10 MeV
0,19
Electrons >2MeV
3 540,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
473,3
Proton Density (p/cc)
0,2
Ion Temperature (°K)
43 400,0
IMF Bt (nT)
4,8
IMF Bz (nT)
0,3
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-84751 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-84751 min.
Data source
NOAA SWPC
Mise à jour des indices : 26/02/2026 12:56:39 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 »…)
