Convective Outlook
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Sun Apr 05 2020 Valid 051300Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe weather is not expected through tonight. ...Synopsis/Discussion... In mid/upper levels, the large-scale pattern will be dominated by persistent blockiness over northern Canada, related to a strong anticyclone over the Arctic Islands. To the southwest, split flow will occur around a strong low slowly digging southeastward off the northern CA coastline. To the cyclone's east, broad fetch of southwesterly flow will foster warm advection and increasing low/ middle-level moisture, beneath cold midtropospheric temperatures. Resulting marginal destabilization will spread across much of the West, then as far as parts of the north-central Plains overnight, supporting isolated to widely scattered, episodic, weak thunderstorms. Downstream, moisture-channel imagery indicates a subtle perturbation from the southern upper Great Lakes to the lower Ohio Valley. This feature should pivot gradually eastward/east-southeastward across the interior Mid-Atlantic between 00-06Z. Associated destabilization aloft, overlying weak low-level moisture and diurnally driven boundary-layer heating of higher terrain, may promote isolated thunderstorms over parts of the central Appalachians, with MLCAPE generally below 500 J/kg. Well-mixed subcloud layers suggest potential for locally gusty winds, but the severe threat appears minimal. In the southern stream, a convectively enhanced, low-amplitude, but complex shortwave trough is evident in satellite imagery over the north-central Gulf and adjoining coastal areas. This feature should proceed east-southeastward across the northeastern Gulf and FL through the period. In concert with diurnal heating, favorable low-level moisture, and possible sea-breeze development later today, a few thunderstorms may form over coastal south FL. Despite seemingly favorable deep/speed shear, weak instability above the boundary layer should limit storm organization. ..Edwards.. 04/05/2020Read more
Updated 5 April 2020 | 7:45 am