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 : 30/03/2026 09:07:36 UTC
Il y a actuellement 11 message(s) (dont 4 alerte(s) et 11 message(s) encore actif(s) au SWPC)
ALERT : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu   29/03/2026 12:47:00 UTC   > Détails
n/a
Space Weather Message Code: ALTEF3 Serial Number: 3660 Issue Time: 2026 Mar 29 1247 UTC CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3659 Begin Time: 2026 Mar 22 1430 UTC Yesterday Maximum 2MeV Flux: 1596 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. Fermer
WARNING : Geomagnetic K-index of 4 expected   29/03/2026 15:48:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5304 Issue Time: 2026 Mar 29 1548 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2026 Mar 29 1546 UTC Valid To: 2026 Mar 30 0900 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
ALERT : X-Ray Flux exceeded M5   30/03/2026 03:07:00 UTC   > Détails
n/a
Space Weather Message Code: ALTXMF
Serial Number: 521
Issue Time: 2026 Mar 30 0307 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2026 Mar 30 0306 UTC
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

ALERT : Type II Radio Emission   30/03/2026 03:22:00 UTC   > Détails
Impact terrestre : 31/03/2026 01:12:00 UTC
Space Weather Message Code: ALTTP2 Serial Number: 1473 Issue Time: 2026 Mar 30 0322 UTC ALERT: Type II Radio Emission Begin Time: 2026 Mar 30 0300 UTC Estimated Velocity: 1872 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 : X-ray Event exceeded X1   30/03/2026 03:53:00 UTC   > Détails
n/a
Space Weather Message Code: SUMX01 Serial Number: 212 Issue Time: 2026 Mar 30 0353 UTC SUMMARY: X-ray Event exceeded X1 Begin Time: 2026 Mar 30 0247 UTC Maximum Time: 2026 Mar 30 0319 UTC End Time: 2026 Mar 30 0344 UTC X-ray Class: X1.5 Location: S27E42 NOAA Scale: R3 - Strong www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point. Radio - Wide area blackout of HF (high frequency) radio communication for about an hour. Fermer
SUMMARY : CANCEL X-ray Event exceeded X1   30/03/2026 05:16:00 UTC   > Détails
n/a
Space Weather Message Code: SUMX01 Serial Number: 213 Issue Time: 2026 Mar 30 0516 UTC CANCEL SUMMARY: X-ray Event exceeded X1 Cancel Serial Number: 212 Original Issue Time: 2026 Mar 30 0353 UTC Comment: The flare maximum was recorded as an X1.4. www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point. Radio - Wide area blackout of HF (high frequency) radio communication for about an hour. Fermer
SUMMARY : X-ray Event exceeded X1   30/03/2026 05:18:00 UTC   > Détails
n/a
Space Weather Message Code: SUMX01 Serial Number: 214 Issue Time: 2026 Mar 30 0518 UTC SUMMARY: X-ray Event exceeded X1 Begin Time: 2026 Mar 30 0247 UTC Maximum Time: 2026 Mar 30 0319 UTC End Time: 2026 Mar 30 0344 UTC X-ray Class: X1,4 Location: S27E42 NOAA Scale: R3 - Strong www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point. Radio - Wide area blackout of HF (high frequency) radio communication for about an hour. Fermer
SUMMARY : 10cm Radio Burst   30/03/2026 05:43:00 UTC   > Détails
n/a
Space Weather Message Code: SUM10R Serial Number: 903 Issue Time: 2026 Mar 30 0543 UTC SUMMARY: 10cm Radio Burst Begin Time: 2026 Mar 30 0254 UTC Maximum Time: 2026 Mar 30 0304 UTC End Time: 2026 Mar 30 0342 UTC Duration: 48 minutes Peak Flux: 1800 sfu Latest Penticton Noon Flux: 158 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
WATCH : Geomagnetic Storm Category G2 Predicted   30/03/2026 06:27:00 UTC   > Détails
n/a
Space Weather Message Code: WATA30 Serial Number: 268 Issue Time: 2026 Mar 30 0627 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: Mar 30: G1 (Minor) Mar 31: G2 (Moderate) Apr 01: G1 (Minor) THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT 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
ALERT : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu   30/03/2026 07:42:00 UTC   > Détails
n/a
Space Weather Message Code: ALTEF3 Serial Number: 3661 Issue Time: 2026 Mar 30 0742 UTC CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3660 Begin Time: 2026 Mar 22 1430 UTC Yesterday Maximum 2MeV Flux: 3755 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. Fermer
WARNING : EXTENDED Geomagnetic K-index of 4 expected   30/03/2026 08:55:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5305 Issue Time: 2026 Mar 30 0855 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5304 Valid From: 2026 Mar 29 1546 UTC Now Valid Until: 2026 Mar 30 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

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
153
SSN
125
Ap
12
Kp
3
Kp Lat.
60,4°
X-Ray (HAF)
C4,1 (11,11 MHz)
Protons E>10 MeV
0,20
Electrons >2MeV
701,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
455,0
Proton Density (p/cc)
4,1
Ion Temperature (°K)
97 800,0
IMF Bt (nT)
8,6
IMF Bz (nT)
-4,7
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-130601 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=10)
Impact as low as
62,5°
Expected in
-130601 min.
Data source
NOAA SWPC
Mise à jour des indices : 30/03/2026 09:06:36 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 »…)