Indices solaires, géomagnétiques et alertes HF – Multimode.fr

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 : 07/12/2025 21:58:02 UTC
Il y a actuellement 7 message(s) (dont 4 alerte(s) et 4 message(s) encore actif(s) au SWPC)

ALERT : Type II Radio Emission 04/12/2025 03:03:00 UTC > Détails

Impact terrestre : 09/12/2025 03:13:00 UTC

Space Weather Message Code: ALTTP2 Serial Number: 1450 Issue Time: 2025 Dec 04 0303 UTC ALERT: Type II Radio Emission Begin Time: 2025 Dec 04 0246 UTC Estimated Velocity: 345 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

ALERT : Type II Radio Emission 06/12/2025 20:51:00 UTC > Détails

Impact terrestre : 08/12/2025 09:01:00 UTC

Space Weather Message Code: ALTTP2 Serial Number: 1451 Issue Time: 2025 Dec 06 2051 UTC ALERT: Type II Radio Emission Begin Time: 2025 Dec 06 2040 UTC Estimated Velocity: 1143 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

SUMMARY : 10cm Radio Burst 06/12/2025 20:54:00 UTC > Détails

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Space Weather Message Code: SUM10R Serial Number: 892 Issue Time: 2025 Dec 06 2054 UTC SUMMARY: 10cm Radio Burst Begin Time: 2025 Dec 06 2035 UTC Maximum Time: 2025 Dec 06 2036 UTC End Time: 2025 Dec 06 2039 UTC Duration: 4 minutes Peak Flux: 1100 sfu Latest Penticton Noon Flux: 200 sfu Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications. Fermer

WARNING : Geomagnetic K-index of 4 expected 07/12/2025 04:23:00 UTC > Détails

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Space Weather Message Code: WARK04 Serial Number: 5176 Issue Time: 2025 Dec 07 0423 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2025 Dec 07 0422 UTC Valid To: 2025 Dec 07 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. Fermer

WATCH : Geomagnetic Storm Category G3 Predicted 07/12/2025 04:43:00 UTC > Détails

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Space Weather Message Code: WATA50 Serial Number: 94 Issue Time: 2025 Dec 07 0443 UTC WATCH: Geomagnetic Storm Category G3 Predicted Highest Storm Level Predicted by Day: Dec 08: G1 (Minor) Dec 09: G3 (Strong) Dec 10: G1 (Minor) THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT Comment: Watches for G3 (Strong) on 09 Dec and G1 (Minor) on 10 Dec are in anticipation of CME arrival from the M8 flare at 06/2039 UTC. www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude. Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices. Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur. Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur. Radio - HF (high frequency) radio may be intermittent. Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon. Fermer

ALERT : Geomagnetic K-index of 4 07/12/2025 06:01:00 UTC > Détails

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Space Weather Message Code: ALTK04 Serial Number: 2614 Issue Time: 2025 Dec 07 0601 UTC ALERT: Geomagnetic K-index of 4 Synoptic Period: 0300-0600 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

ALERT : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu 07/12/2025 21:39:00 UTC > Détails

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Space Weather Message Code: ALTEF3 Serial Number: 3573 Issue Time: 2025 Dec 07 2139 UTC CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3572 Begin Time: 2025 Dec 05 1530 UTC Yesterday Maximum 2MeV Flux: 2135 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. 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

n/a

HF Bands Noise Level

S1-S2

Indices bruts

SFI

189

SSN

129

Kp Lat.

62,4°

X-Ray (HAF)

C3,1 (9,87 MHz)

Protons E>10 MeV

0,30

Electrons >2MeV

674,0

304A (SOHO)

304A (SDO/EVE)

376,0

Solar Wind (km/s)

413,3

Proton Density (p/cc)

1,0

Ion Temperature (°K)

91 100,0

IMF Bt (nT)

7,2

IMF Bz (nT)

5,5

Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes

North auroral activity

5 (HPI=9)

Impact as low as

62,5°

Expected in

-7 min.

Data source

NOAA SWPC

South auroral activity

5 (HPI=10)

Impact as low as

62,5°

Expected in

-7 min.

Data source

NOAA SWPC

Mise à jour des indices : 07/12/2025 21:57:02 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 »…)