11AM Day 2 Convective Outlook for Wednesday, February 18. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Isolated to widely scattered thunderstorms are possible along parts of the West Coast, lower Ohio/mid-Mississippi Valley, and lower Great Lakes regions. Severe weather is not anticipated.
Synopsis
A pair of successive shortwave troughs are expected to progress north-northeastward on Wednesday into Thursday morning. The initial, weaker perturbation will move from the mid-Mississippi Valley into the upper Ohio Valley. Some thunderstorm potential will exist ahead of this feature within a warm advection regime in lower Michigan into northeast Ohio and northwest Pennsylvania.
Farther west, a more potent shortwave will move from the lower Colorado Valley/western Great Basin into the central Plains by Thursday morning. In its wake, general troughing will in the West. Cold temperatures aloft will foster potential for isolated thunderstorms along much of the West Coast. A few lightning flashes may also occur ahead of the progressing shortwave trough in the eastern Great Basin. However, ample cloud cover and cool/cold temperatures will keep such activity quite sparse.
A surface low will develop late in the period in the central High Plains and shift into eastern Kansas/western Missouri by Thursday morning. Mid-level ascent and warm/moist advection will gradually increase from the Mississippi/Ohio confluence into parts of the lower Ohio Valley. There is some signal from both global and regional CAM guidance for development very late in the period near the Mississippi/Ohio confluence. Farther north and east, capping may prevail given more nebulous forcing. Severe weather is not anticipated with any of the activity in these regions.