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 : 03/12/2025 20:02:02 UTC
Il y a actuellement 9 message(s) (dont 6 alerte(s) et 8 message(s) encore actif(s) au SWPC)
ALERT : Type II Radio Emission
01/12/2025 04:03:00 UTC > DétailsImpact terrestre : 04/12/2025 16:07:00 UTC
Space Weather Message Code: ALTTP2
Serial Number: 1449
Issue Time: 2025 Dec 01 0403 UTC
ALERT: Type II Radio Emission
Begin Time: 2025 Dec 01 0319 UTC
Estimated Velocity: 490 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.
FermerALERT : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu
03/12/2025 07:06:00 UTC > Détailsn/a
Space Weather Message Code: ALTEF3
Serial Number: 3570
Issue Time: 2025 Dec 03 0706 UTC
CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3569
Begin Time: 2025 Nov 25 1450 UTC
Yesterday Maximum 2MeV Flux: 8535 pfu
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.
FermerWARNING : Geomagnetic K-index of 4 expected
03/12/2025 10:22:00 UTC > Détailsn/a
Space Weather Message Code: WARK04
Serial Number: 5171
Issue Time: 2025 Dec 03 1022 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Dec 03 1022 UTC
Valid To: 2025 Dec 03 2359 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
03/12/2025 14:23:00 UTC > Détailsn/a
Space Weather Message Code: ALTK04
Serial Number: 2612
Issue Time: 2025 Dec 03 1423 UTC
ALERT: Geomagnetic K-index of 4
Synoptic Period: 1200-1500 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
03/12/2025 14:25:00 UTC > Détailsn/a
Space Weather Message Code: WARK05
Serial Number: 2145
Issue Time: 2025 Dec 03 1425 UTC
WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 Dec 03 1425 UTC
Valid To: 2025 Dec 04 0000 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
03/12/2025 14:52:00 UTC > Détailsn/a
Space Weather Message Code: ALTK05
Serial Number: 1920
Issue Time: 2025 Dec 03 1452 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.
FermerALERT : Geomagnetic K-index of 5
03/12/2025 19:41:00 UTC > Détailsn/a
Space Weather Message Code: ALTK05
Serial Number: 1921
Issue Time: 2025 Dec 03 1941 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.
FermerWARNING : Geomagnetic K-Index of 6 expected
03/12/2025 19:53:00 UTC > Détailsn/a
Space Weather Message Code: WARK06
Serial Number: 627
Issue Time: 2025 Dec 03 1953 UTC
WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 Dec 03 1952 UTC
Valid To: 2025 Dec 03 2359 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.
FermerALERT : Geomagnetic K-index of 6
03/12/2025 19:58:00 UTC > Détailsn/a
Space Weather Message Code: ALTK06
Serial Number: 677
Issue Time: 2025 Dec 03 1958 UTC
ALERT: Geomagnetic K-index of 6
Synoptic Period: 1800-2100 UTC
Active Warning: Yes
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
S3-S4
Indices bruts
SFI
199
SSN
177
Ap
17
Kp
4
Kp Lat.
58,3°
X-Ray (HAF)
C2,0 (7,99 MHz)
Protons E>10 MeV
0,19
Electrons >2MeV
161,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
466,6
Proton Density (p/cc)
32,7
Ion Temperature (°K)
99 900,0
IMF Bt (nT)
10,6
IMF Bz (nT)
0,6
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
8 (HPI=45)
Impact as low as
56,7°
Expected in
-6 min.
Data source
NOAA SWPC
South auroral activity
8 (HPI=38)
Impact as low as
56,7°
Expected in
-6 min.
Data source
NOAA SWPC
Mise à jour des indices : 03/12/2025 20:01:02 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 »…)
