ACUS02 KWNS 150435 SWODY2 SPC AC 150434 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1134 PM CDT Mon Oct 14 2024 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered weak thunderstorm activity is possible across the Pacific Northwest into portions of the Great Basin and Rockies Wednesday afternoon into evening. Additional thunderstorm development is possible across Deep South Texas and near or south of the Florida Keys. ...Discussion... Models indicate that flow will remain generally progressive across the mid-latitude Pacific into western North America through this period, and large-scale mid-level troughing appears likely to continue developing inland of the Pacific coast through much of the Intermountain West, Rockies and northern Great Plains. Within this regime, one significant short wave impulse is forecast to progress inland of the British Columbia coast and across the Canadian Rockies by late Wednesday night, while a similar trailing impulse digs into the northern Pacific coast. A remnant perturbation already inland to the southwest of the Four Corners region is forecast to become absorbed within the evolving larger-scale cyclonic flow across the Wyoming/Colorado Rockies, after being forced northeastward. Downstream, developments remain somewhat more unclear near the Atlantic Seaboard, as a mid-level ridge becomes increasing prominent over the subtropical Atlantic. Initially amplified large-scale troughing along a positively tilted axis across the Atlantic Seaboard still appears likely to reach peak amplitude near or just before 12Z Wednesday, but guidance now appears to be trending a bit less progressive with a short wave perturbation emerging from the base of the troughing. It appears that this feature may contribute to the evolution of a modest mid-level low just offshore of the Mid Atlantic coast, while a trailing perturbation digs across the eastern Gulf Coast region. However, associated surface wave development is still forecast to remain along a frontal zone well east of the Mid Atlantic coast. As the evolving upper pattern supports deepening surface troughing to the east of the Canadian/northern U.S. Rockies, the center of initially expansive cold surface ridging to the east of the Rockies is forecast to shift from the central Great Plains/lower Missouri Valley to the lower Ohio/Tennessee Valleys vicinity. However, the ridge likely will maintain a considerable stabilizing influence across much of the Gulf Coast region and northwestern Gulf of Mexico. Inland of the lower Rio Grande Valley, low-level moistening is forecast to remain limited, and generally elevated to the east of the higher terrain of southwestern Texas into New Mexico. ...Florida Keys and Deep South Texas vicinities... While the front over the western Atlantic tends to slowly advance away from much of the Atlantic Seaboard, its trailing flank is forecast to stall near or southeast of the Florida Keys, and weaken across the south central Gulf of Mexico through lower Texas coast/Rio Grande vicinity. Seasonably high boundary-layer moisture content along this zone could support moderately large CAPE and widely scattered thunderstorm activity. ...Pacific Northwest into eastern Great Basin/adjacent Rockies... Despite limited moisture availability, mid/upper forcing for ascent, cooling aloft and orography may contribute to scattered weak thunderstorm activity Wednesday afternoon and evening. ..Kerr.. 10/15/2024 $$