SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Mon Oct 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL FLORIDA PENINSULA... ...SUMMARY... Isolated strong to severe thunderstorms capable of producing occasional damaging winds may occur this afternoon and early evening across parts of the Florida Peninsula. ...20z Update... The previous forecast largely remains on track. The only adjustment was a westward expansion of 5% wind (Marginal) risk probabilities into the Tampa Bay area. A remnant line of thunderstorms that began in the FL Panhandle early this morning has maintained intensity as it migrates east/southeast towards the western FL coast. KTBW imagery shows a well-balanced updraft/downdraft convergence zone, and recent GOES IR imagery shows cooling cloud-top temperatures, indicative of a slight intensification over the past hour. Although portions of this line have only produced 20-30 mph gusts thus far as it makes landfall, the most intense portion of the storm may impact near/north of the Tampa Bay area in the coming hours, warranting an expansion of risk probabilities. For additional details, see recently issued MCD #2189 and the previous discussion below. ..Moore.. 10/27/2025 .PREV DISCUSSION... /ISSUED 1112 AM CDT Mon Oct 27 2025/ ...Florida... Strong to locally severe convection has moved southeast and offshore from the Apalachicola vicinity, so the Marginal Risk has been removed from this area. Nearly all guidance suggests this activity will weaken as it approaches the west coast of the FL Peninsula this afternoon and moves over cooler shelf waters. Other isolated strong to severe thunderstorms may develop this afternoon across interior portions of the central FL Peninsula as continued strong diurnal heating occurs over this area along/south of a stalled front. Even though lapse rates aloft will remain modest (reference 12Z observed sounding from TBW), weak low-level flow will veer to west-southwesterly and strengthen with height through mid/upper levels on the southern periphery of an upper trough over the Southeast. The forecast combination of moderate instability and around 30-35 kt of deep-layer shear may support occasional convective organization. Isolated damaging winds appear possible with the stronger cores as low-level lapse rates steepen through the afternoon. These thunderstorms should move eastward and mostly offshore through early evening before eventually weakening with the loss of daytime heating. ...Central High Plains... An upper trough over the Northwest and northern Rockies will amplify as it ejects eastward over the northern/central Plains through the period. Surface lee troughing should deepen this afternoon/evening as large-scale ascent associated with the upper trough overspreads the central High Plains. However, recent visible satellite imagery and surface observations show limited low-level moisture and broken to widespread low clouds over this region. This should hinder the development of any more than meager buoyancy through the afternoon/evening. Even though some high-resolution guidance shows a stronger thunderstorm or two developing in eastern CO/western KS, the overall thermodynamic environment appears too marginal to include low severe probabilities at this time.
