


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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209 ACUS01 KWNS 181247 SWODY1 SPC AC 181246 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sat Oct 18 2025 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE ARKLATEX AND OZARKS INTO PARTS OF THE LOWER/MID MS VALLEYS... ...SUMMARY... Scattered severe thunderstorms are possible mainly this afternoon into tonight across parts of the Ark-La-Tex, Ozarks, mid to lower Mississippi and lower Ohio Valleys. Damaging winds, a few tornadoes and hail may occur. ...Synopsis... A vigorous mid/upper-level trough will dig southeastward across the central/northern Plains later today. Water-vapor imagery this morning shows a potent shortwave trough over the southern High Plains and this feature will quickly move toward the ArkLaTex by early evening. The combination of these systems will eventually result in development of a deep and progressive trough becoming established over the MS Valley by early Sunday morning. Morning surface analysis places a low over northern OK and frontal zone extending northeast. The low will develop northeast during the period and eventually reach Lower MI by early Sunday morning. ...Eastern TX/OK into parts of the lower/mid MS Valley... Morning radar/satellite imagery shows the initial shower/storm development over western MO/eastern KS into parts of west TX. This activity will likely increase in coverage and intensity from southern MO into eastern OK/TX through midday, as the ejecting shortwave trough approaches the region. A plume of 60s deg F surface dewpoints and some diurnal destabilization will lead to moderate buoyancy by afternoon. As storms gradually develop, strengthening deep-layer shear will support storm organization. Some initial supercell development could pose a threat for hail with some tornado/damaging wind potential also perhaps accompanying this activity. Increasing ascent and upscale growth into convective bands/lines will favor a continued risk for damaging gusts and possibly some embedded brief tornado potential. Prior forecast thinking of reduced buoyancy centered over eastern AR/western TN may result in storms weakening as they move into this area. However, a notable increase in the low-level jet may support some reintensification of storms during the evening near and east of the lower MS Valley towards evening and into tonight. A continued threat for damaging winds and possibly a couple of tornadoes may persist overnight near and north of the central Gulf Coast vicinity. ...Parts of the Ohio Valley/Midwest... Latest model guidance generally shows scattered storms developing later this afternoon coincident with diurnal destabilization. Initial storm development over the MO/IL/western KY vicinity will tend to grow upscale into a forced thunderstorm band later this evening/overnight as forcing for ascent increases and overspreads the region from the west. The magnitude of the severe threat may be limited by scant instability, but strong ascent and strong deep-layer flow/shear will support some potential for damaging gusts and perhaps a brief tornado or two. ..Smith/Bentley.. 10/18/2025 $$