Un forte brillamento garantisce le aurore?
No. Un brillamento non equivale a un’espulsione diretta verso la Terra. Contano anche vento solare, campo magnetico, posizione, buio e meteo.
Quanto è attivo il Sole oggi? Segui brillamenti, tempeste geomagnetiche e vento solare, poi consulta le previsioni delle aurore per la tua zona.
Le classi vanno da A a X passando per B, C e M. A parità di numero, ogni lettera indica un’intensità dieci volte superiore alla precedente.

Bt è l’intensità totale del campo. Bz negativo a lungo indica un campo verso sud e può favorire l’ingresso di energia, ma non garantisce aurore.
Kp va da 0 a 9; la scala delle tempeste geomagnetiche inizia a 5. È un indice globale, non la probabilità di vedere aurore in una città.
:Product: 3-Day Forecast
:Issued: 2026 Oct 31 0030 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
A. NOAA Geomagnetic Activity Observation and Forecast
The greatest observed 3 hr Kp over the past 24 hours was 4 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Oct 31-Nov 02 2026 is 5.00 (NOAA Scale
G1).
NOAA Kp index breakdown Oct 31-Nov 02 2026
Oct 31 Nov 01 Nov 02
00-03UT 5.00 (G1) 3.67 2.67
03-06UT 4.67 (G1) 4.67 (G1) 2.33
06-09UT 4.33 3.33 2.33
09-12UT 4.00 2.67 2.33
12-15UT 3.00 2.33 2.33
15-18UT 3.00 3.33 2.00
18-21UT 3.67 3.67 2.33
21-00UT 4.00 3.33 2.67
Rationale: The geomagnetic field is likely to reach G1 (Minor)
geomagnetic storm levels on 31 Oct - 01 Nov due to influence from a
positive polarity CH HSS. Unsettled conditions are likely on 02 Nov as
CH HSS influence wanes.
B. NOAA Solar Radiation Activity Observation and Forecast
Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was
below S-scale storm level thresholds.
Solar Radiation Storm Forecast for Oct 31-Nov 02 2026
Oct 31 Nov 01 Nov 02
S1 or greater 1% 1% 1%
Rationale: No S1 (Minor) or greater solar radiation storms are expected.
No significant active region activity favorable for radiation storm
production is forecast.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Oct 31-Nov 02 2026
Oct 31 Nov 01 Nov 02
R1-R2 1% 1% 1%
R3 or greater 1% 1% 1%
Rationale: No R1 (Minor) or greater radio blackouts are expected. No
significant active region flare activity is forecast.
:Product: Forecast Discussion
:Issued: 2026 Oct 31 0030 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity
.24 hr Summary...
Solar activity continued at very low levels. Newly numbered Region 4564
(N12E75, Hsx/alpha) rotated around the E limb with no apparent trailer
spot. It was mostly quiet and stable.
No Earth-directed CMEs were observed at the available coronagraph
imagery.
.Forecast...
Solar activity is expected to be at very low levels with a slight chance
for isolated C-class flares through 02 Nov.
Energetic Particle
.24 hr Summary...
The greater than 2 MeV electron flux reached high levels, with a peak
flux of 4,488 pfu observed at 30/1430 UTC. The greater than 10 MeV
proton flux remained steady at background levels.
.Forecast...
The greater than 2 MeV electron flux is expected to decrease to normal
to moderate levels on 31 Oct Oct and remain there through 02 Nov. The
greater than 10 MeV proton flux is anticipated to persist at background
levels through 02 Nov.
Solar Wind
.24 hr Summary...
Solar wind parameters suggested mild influence from a solar sector
boundary crossing. Total magnetic field strength reached a peak of 9 nT
and the Bz component reached as far south as -8 nT. Solar wind speeds
remained low, with values observed between 307-354 km/s. Phi angle
transitioned from mostly negative to positive after 30/0513 UTC.
.Forecast...
Solar wind disturbances are likely to be observed on 31 Oct and slow
wane through 02 Nov, due to the anticipated arrival of a recurrent,
equatorial, positive polarity CH HSS.
Geospace
.24 hr Summary...
The geomagnetic field was at quiet to active levels during the period.
.Forecast...
The geomagnetic field is expected to reach G1 (Minor) geomagnetic storm
levels on 31 Oct - 01 Nov due to influence from a positive polarity CH
HSS. Unsettled conditions are likely on 02 Nov as CH HSS influence
wanes.
:Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2026 Oct 26 0118 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# https://www.swpc.noaa.gov/content/subscription-services
#
# 27-day Space Weather Outlook Table
# Issued 2026-10-26
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2026 Oct 26 88 5 2
2026 Oct 27 84 5 2
2026 Oct 28 84 5 2
2026 Oct 29 84 5 2
2026 Oct 30 84 5 2
2026 Oct 31 84 30 5
2026 Nov 01 84 20 4
2026 Nov 02 82 10 3
2026 Nov 03 82 5 2
2026 Nov 04 82 5 2
2026 Nov 05 82 10 3
2026 Nov 06 82 10 3
2026 Nov 07 82 10 3
2026 Nov 08 84 5 2
2026 Nov 09 84 15 4
2026 Nov 10 82 10 3
2026 Nov 11 82 10 3
2026 Nov 12 80 10 3
2026 Nov 13 80 5 2
2026 Nov 14 80 5 2
2026 Nov 15 80 5 2
2026 Nov 16 80 10 3
2026 Nov 17 80 20 4
2026 Nov 18 80 20 4
2026 Nov 19 80 10 3
2026 Nov 20 80 5 2
2026 Nov 21 80 5 2
:Product: Summary of Space Weather Observations dayobs.txt
:Issued: 2026 Oct 31 0030 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# https://www.swpc.noaa.gov/content/subscription-services
#
# Summary of Space Weather Observations
#
:Solar_Region_Summary: 2026 Oct 30
# Region Location Sunspot Characteristics
# Helio Spot Spot Mag.
# Num Lat.,CMD Long. Area Extent class count class
4563 S19W94 353 10 1 AXX 1 A
4564 N04E56 203 30 5 CRO 4 B
4565 N12E75 184 60 2 HSX 1 A
L’attività del Sole e i cambiamenti nello spazio vicino alla Terra. Brillamenti, particelle energetiche e tempeste geomagnetiche sono fenomeni diversi.
No. Un brillamento non equivale a un’espulsione diretta verso la Terra. Contano anche vento solare, campo magnetico, posizione, buio e meteo.
Osservazioni e previsioni pubbliche possono subire ritardi o revisioni. Non garantiscono aurore visibili né sicurezza operativa. Per decisioni importanti segui le indicazioni ufficiali.