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SPC Jul 30, 2024 1630 UTC Day 1 Convective Outlook

1 year ago

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 30 2024 Valid 301630Z - 311200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY INTO THE MID MISSISSIPPI VALLEY/MIDWEST... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Severe thunderstorms are expected today into tonight across a broad area from eastern Nebraska and Iowa into parts of the Midwest, Tennessee Valley and southern Appalachians, with multiple swaths of damaging winds likely within this corridor. Severe thunderstorms are also possible across parts of the northern Plains. ...Mid Missouri Valley into the Midwest/Ohio Valley/Southeast... A larger than usual amount of uncertainty remains regarding convective evolution this afternoon though tonight. Ongoing cluster in southern IA will move southeastward across the mid MS Valley into a rapidly destabilizing airmass with enhanced northwesterly winds at mid/upper-levels supporting sufficient deep-layer shear for continued updraft organization. A swath of severe/damaging winds appears likely with this cluster given the favorable parameter space. Therefore, the Enhanced Risk for damaging winds has been extended southeastward to account for the forecast evolution of this MCS. Another ongoing cluster over the lower OH Valley should also pose some threat for severe/damaging winds as it and associated outflow on its southwest flank spreads east-southeastward across KY and perhaps parts of TN the rest of this afternoon/evening. Additional robust thunderstorm development appears possible through the period in a broad corridor from central/eastern NE through the lower OH Valley and Southeast, with swaths of damaging winds likely the main threat. Details on where/when this activity will develop remain rather uncertain. But, isolated supercells may develop across central/eastern NE late this afternoon/evening in the vicinity of a surface low/lee trough. Very large hail may occur with this convection, with a greater threat for severe/damaging winds possible if this activity can grow upscale into another cluster and spread southeastward across the mid MO and mid MS Valleys this evening/overnight. ...Northern Plains... Weak mid-level height falls amid moderate to strong instability should foster to widely scattered thunderstorm development along a surface trough/dryline across parts of the Dakotas this afternoon. Moderate mid-level westerlies should support deep-layer shear around 30-35 kt, sufficient for a few organized storms, including a few supercells, capable of both large hail and damaging gusts this afternoon and evening. ...Mid-Atlantic Vicinity... A weak mid/upper-level trough and will move across the Mid-Atlantic and vicinity through this evening. Scattered thunderstorm development should continue this afternoon from VA into parts of PA. While there is some uncertainty regarding the extent of heating and destabilization due to lingering cloudiness, a couple of stronger cells/clusters may become capable of producing isolated damaging winds. ...Northeast... Weak to locally moderate instability may develop this afternoon from parts of northern New York into northern New England. While storm coverage remains uncertain, deep-layer shear and relatively cool temperatures aloft could support a couple of modestly organized thunderstorms capable of locally damaging winds, and possibly some hail. ..Gleason/Moore.. 07/30/2024 Read more