SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 AM CDT Sat Oct 24 2020 Valid 241300Z - 251200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous U.S. today or tonight. ...Synopsis/Discussion... The mid/upper level feature broadly cyclonic flow covering roughly the northern half of the CONUS. Amplification of the western part of the pattern will occur through the period, related to a nearly zonal trough now evident in moisture-channel imagery from southern MB to southern BC. That portion of this trough over the Canadian Rockies will split off southeastward and strengthen as several vorticity maxima phase, while the eastern part over SK/MB pivots eastward and deforms ahead of a strong shortwave approaching from Nunavut. By 12Z tomorrow, the net result should be a deepening synoptic trough from eastern MT to northern NV and northeastern CA, which will dig southeastward and deepen further on day 2. In the southern stream, a lower-amplitude (but still well-defined) shortwave trough and embedded MCV -- initially over portions of MS and southeastern LA -- will shift eastward across the Deep South through the period. Large-scale forcing associated with this feature, above a moist and minimally capped, diurnally destabilized boundary layer, may foster a relative max in general thunderstorm potential over parts of the central/eastern Gulf Coastal Plain today. Deep-convective potential will be loosely bounded from northeast to southwest along and shortly behind a cold front -- analyzed at 11Z from southeastern QC across southern PA, eastern TN, western AL, and the northwestern Gulf. By 12Z, this front should move to a position across the Carolinas and northern GA, through a frontal wave in AL, to the central Gulf. The Gulf part of the front will weaken substantially as frontogenesis occurs from northeastern NM across northwest/east-central TX, with late-period cyclogenesis over the TX Panhandle. ..Edwards/Mosier.. 10/24/2020
There’s more click here.