SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0142 PM CST Thu Nov 13 2025 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Minimal thunderstorm chances are evident today over parts of central California. Severe weather is not forecast. ...20z Update... No changes were made to the prior outlook. Isolated thunderstorms remain possible beneath an upper low over central CA and near the New England Coast. However, limited moisture and very weak buoyancy should keep severe potential very low. See the prior outlook for more information. ..Lyons.. 11/13/2025 .PREV DISCUSSION... /ISSUED 1021 AM CST Thu Nov 13 2025/ ...Synopsis... A deep upper-level trough will gradually move eastward over the Pacific Coast region today. An embedded deep-layer cyclone is forecast to gradually weaken as it moves east-southeastward off of the northern CA coast. The low/midlevel moisture plume associated with this system will continue to overspread parts of CA through the period. Weak buoyancy (MUCAPE of 100-200 J/kg) within this moist plume will support isolated/sporadic lightning potential with embedded convective elements, especially where orographic lift is maximized in the vicinity of the Sierra Nevada. While low-level flow/shear will remain rather strong into this afternoon, negligible surface-based instability should limit potential for convectively augmented gusts. Elsewhere, cold midlevel temperatures will support weak convection over parts of the Northeast, though the greatest relative lightning potential is expected to remain offshore of southern New England. Some elevated buoyancy may develop late tonight across parts of MO/IL, along the northern periphery of modest 850 mb moisture return, but there is minimal signal for development of deep convection in this region prior to the end of the period.
