Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
114 FXXX12 KWNP 310031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Jul 31 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 reached moderate levels following a long-duration M1.9/Sf flare at 30/1700 UTC from near Region 4492 (N16W74, Hsx/alpha). Coinciding with the flare was an approximately eight-degree-long filament eruption, centered near N20W67. Also associated with this event were two Type II radio sweeps: the first at 30/1627 UTC, with an estimated shock speed of 853 km/s, and the second at 30/1645 UTC, with an estimated speed of 1681 km/s. Additional radio signatures included a Type IV sweep at 30/1631 UTC, and a 17-minute-long F10 cm radio burst that peaked (190 sfu) at 30/1643 UTC. A partial-halo CME was observed in GOES CCOR2 coronagraph imagery, beginning at 30/1715 UTC, as well as a full-halo signature in STEREO COR2 coronagraph imagery at 30/1653 UTC. Initial analysis indicated a possible arrival at Earth early on 02 Aug. Additional analysis is underway to corroborate these results. Regions 4498 (N14E37, Cai/beta-gamma), 4499 (N04E05, Dao/beta-gamma-delta), and 4500 (N18E44, Cao/beta) all observed slight growth during the period, with 4499 developing a delta configuration in its leader spots. The rest of the spot groups were either stable or in decay. .Forecast... Solar activity is expected to be low with a chance for M-class flares (R1-R2, Minor-Moderate) through 02 August. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels. The greater than 10 MeV proton flux reached S1 (Minor) storm levels at 30/1903 UTC. Additionally, the greater than 100 MeV proton flux exceeded 1 pfu at 30/1833 UTC. .Forecast... The greater than 2 MeV electron flux is likely to remain at normal to moderate levels. The greater than 10 MeV proton flux and the greater than 100 MeV proton flux are expected to remain at or above alert thresholds through early 31 Jul. A return to background levels is expected by 01-02 August. Solar Wind .24 hr Summary... Solar wind parameters were at nominal levels. Total field averaged near near 3 nT while the Bz component was between +/-4 nT. Solar wind speed decreased to end the period near 310 km/s. Phi angle was variable, but mostly in a positive sector. .Forecast... There is still a slight, yet diminishing chance for a disturbed solar wind environment on 31 July as the CMEs from 26 and 27 July appear less likely to graze the Earth. An additional disturbance is possible on 01 August with the arrival of an additional CME that left the Sun late on 27 July combined with weak CH HSS influence. Further enhancements could be realized on 02 Aug if the partial halo CME from 30 Jul has a favorable trajectory towards Earth. Geospace .24 hr Summary... The geomagnetic field was quiet. .Forecast... Quiet to unsettled conditions, with isolated active periods, are still possible on 31 Jul, persisting through 01 August due to weak positive polarity CH HSS influences and a combination of either glancing or relatively weak CME effects from events that left the Sun over the course of 26 and 27 July. An increase in storm levels are possible on 02 Aug if the partial halo CME from 30 Jul has a favorable trajectory towards Earth.