SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Sat Jan 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS MORNING INTO THIS AFTERNOON ACROSS CENTRAL FLORIDA... ...SUMMARY... Strong thunderstorms may impact parts of central Florida this morning into this afternoon, and pose at least some risk for a tornado and locally damaging wind gusts. ...Synopsis... Seasonably cold, stable conditions will generally prevail across the U.S. through this period and beyond. A blocking mid-level ridge, centered over the northeastern Pacific, may undergo some suppression and shift inland across British Columbia and the Pacific Northwest coast. However, positively tilted, large-scale downstream troughing likely will be maintained across much of the remainder of North America, reinforced across much of the Southwest by another digging short wave trough. A more notable downstream short wave perturbation is forecast to accelerate across the northern Mid Atlantic into the Canadian Maritimes, after bottoming out across the lower Mississippi/Tennessee Valleys, as a prominent ridge builds across the subtropical western Atlantic and Caribbean. Models indicate that associated forcing for ascent will support more substantive deepening of an initially modest surface frontal wave, as it migrates offshore of the Mid Atlantic coast through the Canadian Maritimes mid day through late tonight. In the wake of the cyclone, cold surface ridging will continue to build to the lee of the Rockies, with the frontal zone demarcating the leading edge of the cold intrusion advancing through the southeastern Gulf of Mexico, Florida Peninsula and away from the remainder of the Atlantic Seaboard. ...Florida... In advance of the cold front, low-level moistening and daytime heating may contribute to a narrow corridor of modest boundary-layer destabilization across the central Florida Peninsula. It appears that this will peak during the early afternoon, aided by weak mid-level cooling. However, guidance also suggests that warm sector clockwise curved low-level hodographs may maximize over inland areas prior to mid morning, before tending to shrink and trend more linear as the deepening surface low progresses northeastward into and offshore of the Mid Atlantic coast. If at least weak boundary-layer destabilization can take place prior to weakening of the low-level shear and forcing for ascent, the environment might become conducive to supercell structures posing a risk for a tornado or locally damaging wind gusts. Otherwise, potential for scattered pre-frontal thunderstorm development may linger over portions of the central Florida Peninsula into this afternoon, accompanied by at least some risk for locally damaging wind gusts, in the presence of strong deep-layer shear. ..Kerr/Halbert.. 01/19/2025