Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
613 ACUS48 KWNS 090848 SWOD48 SPC AC 090847 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CST Sun Nov 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... Modified return flow will slowly build across the western Gulf mid to late week, with a maritime tropical airmass probably reaching parts of the TX Gulf Coast next weekend. As mentioned by WPC`s EPD, run-to-run model variability remains high with a large amount of spread in the potential evolution of a broad upper trough approaching the West Coast on D5/Thursday. This is well illustrated by the change in SPC-CSU GEFS-ML probabilistic guidance over the past 24 hours for D7/Saturday -- from a mesoscale 5% area in the Mid-MS Valley in yesterday`s D8 to a full-latitude 5% from the Rio Grande to the Great Lakes, along with broad 15% and 30% highlights from parts of TX/LA to the Mid-MS Valley. While its parent 00Z GFS appears conducive to severe, over what would likely be a subset of these large highlights, this latest run lacks any semblance of continuity. In addition, other models, such as the EC-AIFS suggest a closed, cutoff low may just be in the process of moving onshore on D7/Saturday, compared to the progressive, full-latitude trough over the Great Plains in this GFS run. For this forecast, will upgrade to Predictability Too Low for D7/Saturday and extend into D8/Sunday for indications of possible severe, probably focused in the South-Central States, within a low predictability pattern. ..Grams.. 11/09/2025