11PM Day 1 Convective Outlook for Sunday, February 22. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Thunderstorms are possible across portions of the Florida Peninsula during the day. Lightning may also occur across coastal areas from North Carolina to southern New England, and over western Washington State.
Discussion
Strong short-wave trough is digging southeast toward the OH Valley late this evening. This feature will phase with the southern stream and induce a surface low off the NC coast early in the period. Intense deepening is expected with this offshore cyclone which will lift north-northeast during the overnight hours.
Isolated thunderstorms may develop along the trailing cold front as it surges south across the FL Peninsula during the day, but poor lapse rates and weak buoyancy suggest the risk for robust convection is not particularly high.
Intense low-level warm advection will aid the potential for lightning discharge in midlevel convection along the middle Atlantic coast and southern New England. Forecast soundings suggest the majority of this activity will be within heavier snow bands along the northwest-north side of the cyclone.
Across the Pacific northwest, significant midlevel cooling and steepening lapse rates are expected along the WA coast by early afternoon. Weak SBCAPE is expected to develop across this region and some risk for lightning is possible with convection that develops within this warm-advection regime.