Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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896 ACUS01 KWNS 291950 SWODY1 SPC AC 291949 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Sat Nov 29 2025 Valid 292000Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN TEXAS INTO WESTERN LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across portions of east and southeast Texas into western Louisiana through tonight. ...20z Update... The previous forecast largely remains on track with only minor adjustments required - mainly removal of thunder probabilities across portions of OK/KS/MO where the mid-level vorticity maximum and surface cold front have already passed through. Across east/southeast TX, modest low-level moisture advection continues northward with temperatures warming into the upper 70s and low 80s for a few locations - a few degrees warmer than anticipated by high-res guidance. This additional heating combined with persistent, but shallow, convective showers across southeast TX lend confidence that at least a few attempts at deeper convection are likely by peak heating in the coming hours. Any appreciable tornado threat will likely be limited to near/along a diffuse warm frontal zone draped roughly from the Houston to Waco, TX area where low-level winds remain south/southeasterly. Further north near the DFW metro, deepening cumulus is noted in visible imagery where the surface cold front is impinging on the northern extent of appreciable MLCAPE. Thunderstorm development along the front appears likely in the coming hours, but the modest buoyancy profiles should modulate convective intensity. See the previous discussion for additional details. ..Moore.. 11/29/2025 .PREV DISCUSSION... /ISSUED 1024 AM CST Sat Nov 29 2025/ ...Central/East/Southeast Texas into Western Louisiana... A mid-level shortwave trough over the Plains this morning will continue to progress quickly east-northeastward today across the mid MS Valley/Midwest and OH Valley. A related surface low over eastern KS will likewise develop northeastward towards IL by this evening, with an attendant cold front sweeping south-southeastward across OK/TX and the ArkLaTex through tonight. Low-level warm/moist advection will continue to aid the northward transport of a partially modified Gulf airmass over portions of central/east TX and perhaps western LA. Thunderstorms should eventually develop by late afternoon/early evening along the front across north-central TX and vicinity, even though large-scale ascent will remain nebulous behind the departing mid-level shortwave trough. Filtered daytime heating will result in modest destabilization across the warm sector today, although mid-level lapse rates are not expected to remain modest. Sufficient deep-layer shear associated with a subtropical/southern branch of a mid/upper-level jet should support some updraft organization. Hail and strong/gusty winds may occur with the stronger cores that can develop and be sustained. But, the surging cold front will likely undercut convection fairly quickly. There also appears to be some chance for isolated thunderstorms to develop ahead of the front from parts of central into southeast TX late this afternoon. The large-scale forcing for ascent with southward extent will remain weak/nebulous at best, but low-level confluence may aid in convective initiation across this area. If these thunderstorms can develop, they would have access to greater instability and sufficient low-level shear to pose some threat for a tornado or two. However, the overall environment still supports maintaining a Marginal Risk given the departing shortwave trough and related large-scale forcing, modest lapse rates aloft, and tendency for the low-level flow to gradually weaken/veer with time through this evening and tonight. $$