####018002561#### FXXX12 KWNP 281231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Jul 28 1230 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 was at low levels. The largest flare was a C5.1/Sf at 28/0319 UTC from Region 4494 (S03W20, Cso/beta). Slight decay was observed in Regions 4494 and 4495 (S03W31, Cro/beta). Consolidation in the leader spots was observed in Region 4496 (N05E13, Cao/beta). New Region 4499 (N04E40, Cro/beta) emerged and was numbered. Regions 4492 (N16W40, Hsx/alpha) and 4498 (N13E70, Cao/beta) appeared relatively stable. Modelling of the CME associated with an M3.2 flare at 26/1529 UTC from Region 4494 and a CME associated with a filament eruption, centered near N25E05, that occurred at 27/0500 UTC indicated glancing influences by late on 30 Jul. .Forecast... Solar activity is expected to be low with a chance for M-class flares (R1-R2, Minor-Moderate) through 30 Jul. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 1,379 pfu at 27/1630 UTC. The greater than 10 MeV proton flux was at background values. .Forecast... The greater than 2 MeV electron flux is likely to return to moderate levels on 28-30 Jul and the greater than 10 MeV proton flux is expected to remain at background levels through 30 Jul. Solar Wind .24 hr Summary... Solar wind parameters were at nominal levels with indications of weak transient influence beginning at 27/1529 UTC, likely the arrival of the 24 Jul CME. Solar wind speed increased from 360-400 km/s with total field increasing from 5 to 7 nT at the time. Solar wind speed remained in the 360-420 km/s range, while total field was between 4 and 8 nT. Phi angle was negative. .Forecast... Mild disturbances are expected to continue through 28 Jul as weak CME influence persists. Another enhancement is likely late on 30 Jul through 31 Jul as glancing effects from the 26-27 Jul CMEs are expected. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... The geomagnetic field is expected to be quiet to active on 29 Jul as weak CME effects persist. Unsettled to active levels are likely again beginning late on 30 Jul with the arrival of the 26-27 Jul CMEs. ####018002242#### FXXX10 KWNP 281231 DAYTDF :Product: 3-Day Forecast :Issued: 2026 Jul 28 1230 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 3 (below NOAA Scale levels). The greatest expected 3 hr Kp for Jul 28-Jul 30 2026 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Jul 28-Jul 30 2026 Jul 28 Jul 29 Jul 30 00-03UT 2.33 2.67 3.00 03-06UT 1.33 2.00 1.67 06-09UT 1.67 2.00 2.00 09-12UT 2.33 2.00 2.00 12-15UT 2.67 2.00 2.00 15-18UT 2.00 2.00 2.33 18-21UT 2.67 2.00 3.33 21-00UT 3.67 2.33 4.00 Rationale: The geomagnetic field is expected to be quiet to active (below G1-Minor) on 29 Jul as weak CME effects persist. Unsettled to active levels are likely again beginning late on 30 Jul with the arrival of the 26-27 Jul CMEs. 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 Jul 28-Jul 30 2026 Jul 28 Jul 29 Jul 30 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 Jul 28-Jul 30 2026 Jul 28 Jul 29 Jul 30 R1-R2 30% 30% 30% R3 or greater 1% 1% 1% Rationale: Solar activity is expected to be low with a chance for M-class flares (R1-R2, Minor-Moderate) through 30 Jul.