Alerts:
Space Weather Message Code: ALTK04
Serial Number: 2661
Issue Time: 2026 May 28 1800 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2026 May 28 1800 UTC
Synoptic Period: 1800-2100
Active Warning: YES
Comment:
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.
Space Weather Message Code: ALTK04
Serial Number: 2660
Issue Time: 2026 May 28 1717 UTC
CANCELLED ALERT: Geomagnetic K-index of 4
Cancel Serial Number: 2659
Original Issued Time: 2026-05-28T17:06:00
Cancelled 2026-05-28 17:17 by Forecaster User Incorrectly issued. Did not reach threshold.
Cancelled 2026-05-28 17:17 by Forecaster User Incorrectly issued. Did not reach threshold.
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.
Space Weather Message Code: ALTK04
Serial Number: 2659
Issue Time: 2026 May 28 1706 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2026 May 28 1706 UTC
Synoptic Period: 1500-1800
Active Warning: YES
Comment:
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.
Space Weather Message Code: WARK04
Serial Number: 5349
Issue Time: 2026 May 27 2347 UTC
WARNING: Geomagnetic K-index of 4 expected
Valid From: 2026 May 27 2347 UTC
Valid To: 2026 May 28 0600 UTC
Warning Conditions: Onset
Comment:
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.
Solar-terrestrial indices for 27 May follow.
Solar flux 142 and estimated planetary A-index 11.
The estimated planetary K-index at 1800 UTC on 28 May was 3.67.
No space weather storms were observed for the past 24 hours.
No space weather storms are predicted for the next 24 hours.
Geo Magnetic Forecast:
NOAA Ap Index Forecast
Observed Ap 26 May 008
Estimated Ap 27 May 011
Predicted Ap 28 May-30 May 012-010-006
NOAA Geomagnetic Activity Probabilities 28 May-30 May
Active 40/25/25
Minor storm 10/10/05
Moderate storm 05/01/01
Strong-Extreme storm 01/01/01
NOAA Kp index forecast 28 May - 30 May
May 28 May 29 May 30
00-03UT 3.00 3.33 2.00
03-06UT 3.67 3.00 2.00
06-09UT 3.00 1.67 1.33
09-12UT 2.33 2.00 1.00
12-15UT 2.00 2.00 1.00
15-18UT 1.67 1.67 1.67
18-21UT 2.67 2.33 2.33
21-00UT 1.67 2.33 2.33
Extended Three Day Forecast:
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 May 28-May 30 2026 is 3.33 (below NOAA
Scale levels).
NOAA Kp index breakdown May 28-May 30 2026
May 28 May 29 May 30
00-03UT 2.00 3.33 2.00
03-06UT 2.33 3.00 2.00
06-09UT 2.67 1.67 1.33
09-12UT 3.67 2.00 1.00
12-15UT 2.00 2.00 1.00
15-18UT 1.67 1.67 1.67
18-21UT 2.67 2.33 2.33
21-00UT 1.67 2.33 2.33
Rationale: No G1 (Minor) or greater geomagnetic storms are expected.
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 May 28-May 30 2026
May 28 May 29 May 30
S1 or greater 5% 5% 5%
Rationale: No S1 (Minor) or greater solar radiation storms are expected.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for May 28-May 30 2026
May 28 May 29 May 30
R1-R2 40% 40% 40%
R3 or greater 5% 5% 5%
Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
through 30 May.
Extended Space Weather Discussion:
Solar Activity
.24 hr Summary...
Solar activity remained at low levels. The largest event of the period
was a C3.4 flare originating from Region 4446 (S16E16, Fko/beta-gamma)
at 27/1216 UTC.
There are ten numbered regions on the visible disk. Region 4452
(N09W35, Dai/beta) showed notable growth and new flux emergence,
exhibiting a reversed polarity for its hemisphere. Regions 4445 (N07,
L=163) and 4450 (N10, L=140) decayed to plage, though unassociated
transitory pores were observed to in their vicinities. Regions 4453
(N11W76, Bxo/beta), 4454 (S15E48, Hrx/alpha), and 4455 (N15E65,
Dao/beta) were numbered during the period, the later of which had
rotated sufficiently onto the visible disk to verify a bipolar nature,
so while some foreshortening effects are still present, the regions
classification was updated to reflect this. All other regions
continued either in slow decay or remained stable.
A faint narrow CME first became visible in LASCO C2 at approximately
27/2300 UTC and CCOR1 at 28/0045 UTC. Data gaps in both disk and
coronagraph imagery significantly complicate the analysis, so at the
time of this writing, no on-disk source has been determined and while
analysis suggests an Earth-directed component with potential for a minor
glancing blow on 31 May, confidence in this analysis is low.
No other Earth-directed CMEs were observed in available coronagraph
imagery.
.Forecast...
Solar activity is expected to be at low to moderate levels through 30
May. There remains a chance for isolated M-class flares
(R1-R2/Minor-Moderate) driven by the eruptive potential of the southeast
sunspot groups and newly numbered Region 4455.
Energetic Particle
.24 hr Summary...
The greater than 2 MeV electron flux at geosynchronous orbit was at low
to moderate levels, with a peak flux of 383 pfu observed at 27/1605 UTC.
The greater than 10 MeV proton flux returned to background levels.
.Forecast...
The greater than 2 MeV electron flux is expected to remain at low to
moderate levels through 30 May, as approaching high-speed stream
enhancements are not expected to be sufficient to raise flux levels. The
greater than 10 MeV proton flux is anticipated to remain at background
levels through 30 May.
Solar Wind
.24 hr Summary...
Solar wind parameters reflected slightly elevated background conditions:
The solar wind speed ranged from ~350 km/s to ~425 km/s, while the total
magnetic field (Bt) generally averaged near 6 nT for the majority of the
reporting period; at approximately 28/0250 UTC, Bt began gradually
increasing, reaching a max of 10 nT at 28/1023 UTC. The north-south (Bz)
component displayed high variability, oscillating between a maximum
southward deflection of -8 nT and a positive orientation of +9 nT. The
phi angle was largely in the negative (towards the Sun) sector, with
several deviations to the positive sector throughout the period.
.Forecast...
Solar wind parameters are expected to remain mildly elevated due to weak
-CH HSS influences through 29 May. A return toward near-background,
nominal conditions is anticipated by 30 May.
Geospace
.24 hr Summary...
The geomagnetic field was at quiet to unsettled levels throughout the
reporting period.
.Forecast...
The geomagnetic field is anticipated to be at quiet to unsettled levels,
with a chance for isolated active periods, on 28 May due to continued CH
HSS influences. Unsettled conditions are expected to persist on 29 May
before returning to mostly quiet levels early on 30 May as these effects
subside.
27 Day Forecast:
Date | Radio Flux | Planetary A Index | Largest Kp Index
2026 May 25 140 5 2
2026 May 26 145 8 3
2026 May 27 150 12 4
2026 May 28 140 12 4
2026 May 29 140 8 3
2026 May 30 145 5 2
2026 May 31 145 5 2
2026 Jun 01 145 5 2
2026 Jun 02 145 5 2
2026 Jun 03 150 5 2
2026 Jun 04 145 15 4
2026 Jun 05 140 5 2
2026 Jun 06 135 5 2
2026 Jun 07 135 5 2
2026 Jun 08 130 5 2
2026 Jun 09 125 12 4
2026 Jun 10 130 5 2
2026 Jun 11 130 30 6
2026 Jun 12 125 25 5
2026 Jun 13 120 12 4
2026 Jun 14 115 10 3
2026 Jun 15 115 8 3
2026 Jun 16 110 5 2
2026 Jun 17 110 5 2
2026 Jun 18 110 5 2
2026 Jun 19 115 5 2
2026 Jun 20 120 5 2
v4.16b
v4.X Release 17th Dec 2020)
Fixed New GOES and HPI inputs from noaa for Json (17/12/20).
Addded the ability to add 2 custom Magnetometers in settings (comming soon) (18/10/19).
Improved Hobart Magnetometer code. (18/18/19)
Move all presets into their own pop out side menu. (19/06/19)
Added Composite weather maps (TAS, VIC and SA), thanks to Oz forecast! (19/06/19)
UI Upgrades, Name, Logo and Website Site Changes.
Added custom line widths for most items.
Added GOES Difference (#1 - #2)
Added Ovation-prime model outputs.
v3.8x
Various Updates, New AF Index Algo. (8/12/18)
v3.6x
Added more Presets. Disabled Presets overwriting graph views (6/7/18)
Added GeoSpace Kp Model Prediction. (3/7/18)
Added SWPC Kp Forecast + Observation. (2/7/18)
Removed WingKP and USKp. :( No longer Avaliable. (2/7/18)
Removed feed from www.dunedinaurora.nz (Unreliable). (2/7/18)
Updates to latest JQuery, JQuery Mobile and AmCharts etc. (2/7/18)
Enhanced Pro setting with Dynamic Preasure. (2/7/18)
Added Quickselect preset buttons to main page. (2/7/18)
v3.5x
Added Ruru Observatory Magnetometer. (25/4/28)
Added Forecast Sub Tabset. (1/3/18)
Added Extended Discussion Text, 27Day FC (1/3/18)
Removed Dial, and Added Forecast Report. (28/2/18)
Updated A few settings for better visilation. (28/2/18)
Updated Goes-13 is Now Goes-14 (15/2/18)
Improved Commmunity Activity for faster loads.
Consolidated Proton Density / Dynamic Preasure.
Added Additional Balloon Text.
Added TAFS Visual Probability in %.
User Interface Upgrades.
Add 'Dial' for the basics, with default support.
Added one click presets.
v2.1 - v2.49
Added 'Automatic Chart Update' option in settings.
Database caching enabled, significant load time improvements.
Extension to max 96 hours of data, up from 24.
Added ACE Bt,Bx and By for comparison.
Added More User Presets.
Fixed Orentation Change Alert.
Small layout changes.
Added Header Image.
Removed Top Header to fee up Space, Refresh added to Chart Tab.
Added Community Activity Indicator
Fixed MAG value issues in graph.
Added Second Hobart MAG Source.
Updated Comment Features (Disable).
v2.0
Fixed DSCOVR B? display bug.
Added MAG Stack Feature.
Upgrade to json feeds.
Feeds are timezone and forecast aware, making them super fast.
DB Optimisation, improved DB search times.
Charts are now zoomable, allow selection and export.
Added USAF Kp, Updated Wing Kp.
Added Ovation Aurora Short Term Forecast.
Added Macquarie Island MAG feed.
Added Mawson MAG Feed.
Added Canberra Feed.
Added MAG feed from www.dunedinaurora.nz (Portobello).
Added Brendan's experemental MAG feed (Hobart).
Fixed cookie bug, One Alert is enough for landscape mode.
> v1.0 (Started 20/10/2014)
Mawson and Macquarie Island data is copyright Commonwealth of Australia (Geoscience Australia), and redistributed under Creative Commons v4.
Thanks to INTERMAGNET for promoting high standards of magnetic observatory practice in providing access to these feeds. (www.intermagnet.org).
Local Australian weather composite maps provided by Oz Forecast