####018002158#### FXXX10 KWNP 010031 DAYTDF :Product: 3-Day Forecast :Issued: 2025 Oct 01 0030 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # http://www.swpc.noaa.gov/wwire.html # # 3-Day Forecast # A. NOAA Geomagnetic Activity Observation and Forecast The greatest observed 3 hr Kp over the past 24 hours was 7 (NOAA Scale G3). The greatest expected 3 hr Kp for Oct 01-Oct 03 2025 is 5.67 (NOAA Scale G2). NOAA Kp index breakdown Oct 01-Oct 03 2025 Oct 01 Oct 02 Oct 03 00-03UT 5.33 (G1) 3.33 3.00 03-06UT 5.67 (G2) 3.00 3.00 06-09UT 5.67 (G2) 3.00 2.67 09-12UT 4.67 (G1) 3.67 3.00 12-15UT 3.67 3.00 3.00 15-18UT 3.33 3.00 3.67 18-21UT 2.67 3.33 3.00 21-00UT 3.00 3.67 2.00 Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are expected on 01 Oct due to persistent CME influences. 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 01-Oct 03 2025 Oct 01 Oct 02 Oct 03 S1 or greater 5% 5% 5% 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 Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Sep 30 2025 0940 UTC. Radio Blackout Forecast for Oct 01-Oct 03 2025 Oct 01 Oct 02 Oct 03 R1-R2 60% 60% 60% R3 or greater 15% 15% 15% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely with a slight chance for R3 (strong) event through 03 Oct. ####018001226#### AXXX82 KWNP 010031 DAYOBS :Product: Summary of Space Weather Observations dayobs.txt :Issued: 2025 Oct 01 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: 2025 Sep 30 # Region Location Sunspot Characteristics # Helio Spot Spot Mag. # Num Lat.,CMD Long. Area Extent class count class 4225 N08W0* 177 120 3 HSX 1 A 4226 S09W62 134 90 3 HSX 2 A 4230 S11W37 109 190 9 DAI 16 BGD 4232 N04E22 50 250 8 DHI 9 BG 4233 N17E21 51 120 8 DAO 11 B 4235 N27E24 48 30 2 HSX 1 A 4236 N10E14 58 250 9 DKC 21 BGD 4237 N16W19 91 10 4 BXO 2 B 4238 S14W41 113 60 7 DAO 7 B 4239 S10W41 113 80 2 HSX 1 A 4240 N16E67 5 10 1 AXX 1 A ####018005562#### FXXX12 KWNP 010031 DAYDIS :Product: Forecast Discussion :Issued: 2025 Oct 01 0030 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # http://www.swpc.noaa.gov/wwire.html # # Forecast Discussion # Solar Activity .24 hr Summary... Solar activity has been moderate with multiple M-Class (R1-Minor) flares from various regions. The largest flare was an M2.7 at 30/0940 UTC from Region 4226 (S09W62, Hsx/alpha) which has been stable in its structure throughout the period. There was an associated CME that can be seen in SOHO/Lasco C2 coronagraph imagery starting around 30/0948. At around this same time, a prominance erupted off the SW limb around 30/0840 UTC. The two CMEs were modelled and are projected to pass ahead of Earth. The region with the greatest complexity and highest flare count was Region 4236 (N10E14, Dkc/beta-gamma-delta). The region continues to grow with flux emergence resulting in larger leader and trailer spots. Region 4230 (S11W37, Dai/beta-gamma-delta) was also active, producing an M1.8 at 30/1227 UTC. The region has grown in its size, spot number and magnetic complexity. And its aggressive leader is starting to overrun its stable neighbor, Region 4239 (S10W41, Hsx/alpha). .Forecast... With multiple regions continuing to exhibit growth, flare activity is likely to remain at moderate levels (R1-R2/Minor-Moderate) with a slight chance for an X-class flare (R3-Strong) through 03 Oct. Energetic Particle .24 hr Summary... Weak signals indicating compression of particles ahead of a CME can be seen in the low energy (keV) protons but otherwise particles have been uneventful. The greater than 2 MeV electron flux at geostationary orbit has remained at moderate (100 pfu) levels. With no significant flare/CME activity, the greater than 10 MeV proton flux has remained at background levels. .Forecast... The greater than 2 MeV electron flux is expected to rise over the coming days with the arrival of the positive polarity coronal hole (CH) high speed stream. Barring any significant flares, the greater than 10 MeV proton flux is expected to remain at background levels. Solar Wind .24 hr Summary... Over the last 24-48 hours there have been multiple events that have occurred in the solar wind parameters worth discussing. A slow moving (less than 200 km/s) CME left the Sun on 24/0200 UTC. Its eventual arrival resulted in a prolonged, perturbed interplanetary magnetic field (IMF) with little impact on wind speeds through much of the UTC day on the 29th. A sector boundary crossing (SBC) occurred around 29/1600 UTC which was projected well by WSA model analysis. A SBC alone does not enhance solar wind parameters to the level in which we are seeing currently. However, it does create turbulence within an already disturbed state AND it gives confidence that the corotating interacting region ahead of the coronal hole (CH) high speed stream (HSS) associated with the positive polarity CHs, now west of the central meridian, are on their way. At the time of this writing, signatures that resemble a magnetic cloud within a CME is dominating the IMF. Total field reached 20.4 nT while the north-south (Bz) component dropped as low as 17 nT. Wind speeds have increased substantially from 400 km/s to a maximum of 744 km/s at 30/1921 UTC. There was gradual rotation starting around 30/0040 UTC and then remained steady in the positive sector (away from the Sun) near 135 degrees since. A working theory; an M6.4 from Region 4232 (N03E59 at the time) occurred at 28/0834 UTC - an associated CME lifted off and was observed in coronagraph imagery starting around 28/0900 UTC. The CME was analyzed with a velocity of near 1200 km/s with most of the ejecta passing behind Earth. A glancing blow was possible today. CME signatures can be seen in the observations starting around 30/0000 UTC. Looking at WSA-Enlil, the tail end of the CME rides the magnetic lines occupied by an approaching CIR. If the CME nudged an early arrival of a piece of the CIR, we may be seeing a coupling of the two. It would be early for the CIR, but not unreasonable. The interaction between CMEs and CIRs are very difficult to analyze. This theory is possible - it could explain the mag cloud and the higher velocities - but with only one observation to analyze solar wind its hard to say. .Forecast... Solar wind parameters will remain elevated through 03 Oct. The current CME influence will dissipate into 01 Oct. The primary CIR will likely arrive (if not already) by 02 Oct with the CH HSS becoming geoeffective thereafter. Note, we are close in time to the September/fall equinox, Earths tilt and orbital position make positive polarity CHs more potent when connection begins. Geospace .24 hr Summary... Due to enhanced solar wind parameters (as discussed in the previous section) the geomagnetic field reached G3 (Strong) geomagnetic storming levels during the 30/03-06 UTC synoptic period. It has been at G1-G2 (Minor-Moderate) storming levels otherwise. .Forecast... With solar wind speeds continuing to remain elevated (above 600 km/s), the geomagnetic field is likely to remain enhanced at G1-G2 (Minor-Moderate) storming levels into 01 Oct. Current warnings have been extended through 01/09-12 UTC. -Bri