Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Thu Apr 09 2026 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF CENTRAL AND NORTHEAST KANSAS INTO SOUTHERN NEBRASKA AND FAR NORTHWEST MISSOURI... ...SUMMARY... Severe thunderstorms capable of producing large hail and severe wind gusts are expected late this afternoon and evening across parts of Kansas, southeast Nebraska, and northwest Missouri. Isolated severe thunderstorms may also occur across portions of the south-central High Plains and northern California/southwest Oregon. ...20z Update central and southern Plains... Thunderstorm development remains likely late this afternoon and this evening along the frontal zone from southern NE into northeast KS. While remnant cloud cover has slowed destabilization, sufficient buoyancy and supercell wind profiles will likely support a risk for hail, damaging gusts and perhaps a tornado or two this afternoon/evening. See MCD #367 for specific short-term information. Farther south along the trailing surface trough/dryline, more isolated thunderstorm development is expected across the TX Panhandle and far eastern NM. High cloud bases with deep inverted-v structures could support isolated severe wind gusts with the heavier cores. Storm coverage is likely to decrease farther south where weaker forcing and overall more limited buoyancy is present. Still, isolated storms are possible, and the 5% wind area was expanded southward slightly for the latest hi-res guidance. ...CA and OR... East of an upper low, broad-scale ascent over a modestly warm/moist air mass was supporting widely scattered thunderstorms over portions of northern CA and southern OR. While overall buoyancy is weak (generally below 500 J/kg of MLCAPE), strengthening southerly flow aloft could support a few organized clusters or transient supercells capable of producing isolated strong to severe gusts and some hail. ..Lyons.. 04/09/2026 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Apr 09 2026/ ...Southern High Plains into the Central Plains and Lower/Mid Missouri Valley... Ongoing precipitation/thunderstorms and related cloud cover across north-central/northeast KS into southeast NE/southwest IA is being aided by modest low-level warm/moist advection in the vicinity of a surface front. Current expectations are for this activity to gradually diminish in coverage as it shifts eastward into the northwest MO/southern IA. In its wake, daytime heating may be hampered a bit by residual cloudiness across much of north-central/northeast KS. Even so, continued northward low-level moisture advection is anticipated across the southern/central Plains through the afternoon, with surface dewpoints generally in the upper 40s to low/mid 50s. This, coupled with steep mid-level lapse rates and cold temperatures aloft, will aid in the development of moderate instability (MLCAPE around 1000-1500 J/kg) along/south of a front draped generally west to east across northern KS/MO. Stronger ascent aloft and enhanced westerly flow at mid/upper levels will remain mostly displaced to the north of the central Plains today, as multiple mid-level perturbations rotate through mean mid/upper-level troughing over central/eastern Canada. Still, most guidance continues to suggest that minimal MLCIN will exist in the vicinity of the front in north-central/northeast KS and southeast NE by 22-23Z as surface temperatures warm into the 70s/low 80s. Isolated to scattered thunderstorms are expected to develop across this area by late afternoon/early evening, with modest south-southwesterly low-level winds veering to west-northwesterly at mid/upper levels supporting 35-45 kt of deep-layer shear. Initial convective development will likely be supercellular and pose a threat for mainly large hail (isolated 2+ inches in diameter possible). Fairly large surface temperature-dewpoint spreads with a well-mixed boundary layer and related high cloud bases render considerable uncertainty regarding tornado potential. But, some risk for a tornado or two may focus along/near the front through early evening as effective SRH gradually increases in tandem with a strengthening south-southwesterly low-level jet. Otherwise, the risk for severe/damaging winds may gradually increase through mid evening as thunderstorms tend to cluster/grow modestly upscale. But, the severe wind risk will likely become more limited by late evening with the loss of daytime heating and increasing MLCIN with southward/eastward extent. Isolated thunderstorms may also develop this afternoon farther southwest across the central/southern High Plains along and east of a sharpening surface dryline/lee trough. Overall convective coverage remains highly uncertain given nebulous/weak large-scale ascent this far south. Still, some risk for occasional hail and severe gusts should exist with any sustained cells or clusters that can develop and spread east-southeastward through the late afternoon/early evening. ...Northern California/Southwest Oregon... As an upper-level low over the eastern Pacific approaches the West Coast today, large-scale ascent will overspread portions of northern CA into southern OR with scattered thunderstorm development expected into afternoon. Sufficient moisture and instability should exist inland beneath strengthening deep-layer southwesterly winds ahead of the trough to support semi-organized convection. As low-level lapse rates gradually steepen and flow aloft increases, this activity may be capable of producing isolated strong to severe gusts and possibly some hail.Read more
