Space Weather

Warnings
No Current Warnings
Space Weather Scales
Current Condition and Alerts
Issued: 2021 Sep 25 0905 UTC
Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

Solar-terrestrial indices for 24 September follow.
Solar flux 88 and estimated planetary A-index 8.
The estimated planetary K-index at 0900 UTC on 25 September was 2.

No space weather storms were observed for the past 24 hours.

No space weather storms are predicted for the next 24 hours.
Space Weather Scales
Three Day Forecast
Issued: 2021 Sep 25 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Sep 25-Sep 27 2021 is 6 (NOAA Scale
G2).

NOAA Kp index breakdown Sep 25-Sep 27 2021

Sep 25 Sep 26 Sep 27
00-03UT 3 2 5 (G1)
03-06UT 3 2 6 (G2)
06-09UT 3 1 4
09-12UT 2 1 4
12-15UT 1 2 4
15-18UT 1 4 3
18-21UT 2 4 3
21-00UT 2 5 (G1) 3

Rationale: G1 (Minor) conditions on 26 Sep and G1-G2 (Minor - Moderate)
conditions on 27 Sep are likely in response to anticipated influence
from a positive polarity CH HSS with potential transient influence on 27
Sep.

B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-16 over the past 24 hours, was
below S-scale storm level thresholds.

Solar Radiation Storm Forecast for Sep 25-Sep 27 2021

Sep 25 Sep 26 Sep 27
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 Sep 25-Sep 27 2021

Sep 25 Sep 26 Sep 27
R1-R2 5% 5% 5%
R3 or greater 1% 1% 1%

Rationale: No R1 (Minor) or greater radio blackouts are expected. No
significant active region flare activity is forecast.
Space Weather Scales
Weekly Highlights and Forecasts
Issued: 2021 Sep 20 0042 UTC
Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

Highlights of Solar and Geomagnetic Activity
13 - 19 September 2021

Solar activity reached low levels. Region 2871 (S28, L=359,
class/area=Dao/60 on 19 Sep) produced four C-class flares throughout
the week, the largest of which was a C3 flare observed at 17/0420
UTC, and was the primary source of solar activity. A filament
eruption which lifted off at around 13/0100-0200 UTC and centered
near N35W15, produced an Earth-directed CME that arrived at Earth
early on 17 Sep.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was
normal to moderate throughout the period.

Geomagnetic field activity reached active and G1 (Minor) geomagnetic
storm levels on 17 Sep, and active conditions early on 18 Sep, due
to the arrival of the 13 Sep CME. Quiet to unsettled conditions were
observed on 13 Sep, and quiet conditions were observed throughout
the remainder of the period.

Forecast of Solar and Geomagnetic Activity
20 September - 16 October 2021

Solar activity is expected to be very low with a chance for C-class
flare activity throughout the outlook period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach high levels on 29 Sep-03 Oct and 05-08 Oct. Normal
to moderate levels are expected to persist throughout the remainder
of the outlook period.

Geomagnetic field activity is likely to reach G1 (Minor) geomagnetic
storm levels on 28 Sep, with active conditions likely on 25, 29 Sep,
and 05, 10 Oct, due to the anticipated influence of multiple,
recurrent CH HSSs. Quiet to unsettled and mostly quiet conditions
are expected to prevail throughout the remainder of the outlook
period.
Space Weather Scales
About AIA Images
The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) is designed to provide an unprecedented view of the solar corona, taking images that span at least 1.3 solar diameters in multiple wavelengths nearly simultaneously, at a resolution of ~ 1 arcsec and at a cadence of 10 s or better. The primary goal of the AIA Science Investigation is to use these data, together with data from other SDO instruments and from other observatories, to significantly improve our understanding of the physics behind the activity displayed by the Sun's atmosphere, which drives space weather in the heliosphere and in planetary environments. The AIA will produce data required for quantitative studies of the evolving coronal magnetic field, and the plasma that it holds, both in quiescent phases and during flares and eruptions; the AIA science investigation aims to utilize these data in a comprehensive research program to provide new understanding of the observed processes
Daily Image AIA 171
Channel | Region of atmosphere | Primary ion(s)
171Å | quiet corona, upper transition region | Fe IX
Daily Image AIA 193
Channel | Region of atmosphere | Primary ion(s)
193Å | corona and hot flare plasma | Fe XII, XXIV
Daily Image AIA 304
Channel | Region of atmosphere | Primary ion(s)
304Å | chromosphere, transition region | He II
Daily Video AIA 171
Daily Video AIA 171 PFSS Model
Space Weather Videos



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