12AM Day 1 Convective Outlook for Monday, October 20. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Severe storm risk is low today.
Discussion
Large-scale pattern does not look particularly favorable for severe thunderstorms across the CONUS today. Even so, one notable trough will eject across New England and this feature is expected to aid a narrow band of frontal convection within a strongly sheared environment. Early this morning, lower-mid 50s surface dew points had spread across much of southern and coastal New England. Boundary-layer moisture should gradually increase through sunrise ahead of the cold front such that weak instability is expected to evolve within a poor lapse rate environment. Forecast soundings suggest a few hundred J/kg MUCAPE, but surface-based parcels will struggle to be buoyant except right near the wind shift. With 180dm height falls expected ahead of the trough, a forced line of low-topped convection is expected. At this time it appears instability will be a bit too low to warrant a meaningful risk of severe wind with this activity.
Across southern Florida, trailing cold front will stall across the southern Peninsula. This boundary may serve as the focus for weak convection as PW values remain seasonally high with adequate buoyancy for deep updrafts.