SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1059 AM CST Sun Nov 29 2020 Valid 301200Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NC INTO FAR SOUTHEAST VA... ...SUMMARY... Isolated strong to severe thunderstorms capable of producing damaging winds and perhaps a couple of tornadoes appear possible on Monday from parts of Florida into the Carolinas, Mid-Atlantic and southern New England. ...Synopsis... A closed mid/upper low is expected to develop over the Midwest/central Appalachians on Monday as a large-scale upper trough pivots eastward across the eastern U.S. At the surface, low pressure over WV will lift northward across PA/NY through Monday evening. A trailing cold front is expected to extend from western NC southward through eastern GA and northern FL at the beginning of the period. Meanwhile, a warm front will lift northward across the mid-Atlantic through the afternoon, extending from eastern PA into CT and southern MA by 21z. The cold front will quickly push eastward/southeast across NC/SC and central FL during the daytime hours, moving offshore the Mid-Atlantic and southeastern U.S. coast (except in FL) by 21-00z, and offshore the New England coast during the overnight hours. Dewpoints in the upper 50s to mid 60s F will reside across the warm sector, but instability will be limited due to ongoing convection and cloud cover, especially with northward extent. Still, at least a few hundred J/kg MLCAPE is forecast from FL northward toward the southern New England coast. ...Coastal NC into far Southeast VA... A Slight risk has been maintained with this update across parts of eastern NC into far southeast VA. The most favorable conditions for a mix of semi-discrete supercells and line segments will exist across this area during the morning and early afternoon hours. Backed low level flow to the southeast of the surface low over northern VA will result in enlarged low level hodographs. Strong south/southwesterly shear also will reside over the region in conjunction with MLCAPE values as high as 750 J/kg. Fast storm motion and strong low level winds will favor mainly a locally damaging wind threat, though a couple of tornadoes will be possible. ...Chesapeake Bay vicinity to Coastal Southern New England... Instability will quickly diminish with northward extent as deeper boundary layer moisture lessens and cooler surface temperatures are forecast. Nevertheless, a couple hundred J/kg MLCAPE is evident in forecast soundings in conjunction with strong southerly shear. Forcing for ascent will also be maximized across the area, and low-topped bowing line segments will be possible in the high-shear, low-CAPE environment. Locally damaging gusts will be the main concern with this activity. A shallow low level inversion will likely limit tornado activity, however, this limitation could be overcome near the surface low and along the warm front, and a tornado or two can not be ruled out. ...Central FL... Instability will be maximized over the FL peninsula where deeper low level moisture will be present ahead of the cold front. However, low level convergence will be weak as deep layer flow becomes more parallel to boundary with the surface low and trough ejecting well to the northeast. Nevertheless, forecast soundings indicate adequate instability and shear to support at least a narrow corridor of low-end severe potential before a more subsident airmass moves into the area. The strongest cells during the morning hours could produce locally strong gusts. ..Leitman.. 11/29/2020
There’s more click here.