12AM Day 1 Convective Outlook for Thursday, October 9. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Organized severe storms are not forecast.
Discussion
Large-scale pattern does not appear particularly favorable for robust organized thunderstorms today; although, several areas of concentrated convection are expected.
Upper ridge is forecast to continue across the southern High Plains through the day1 period as a strong low holds off the Oregon Coast. Modest southwesterly flow will encourage higher PW air mass across the southwestern U.S. into the Four Corners region where modest boundary-layer heating will contribute to adequate destabilization for lighting within deeper convective updrafts.
Scattered thunderstorms are also expected across south FL in association with a low-latitude midlevel trough that will drift slowly north through the period. High-PW air mass and poor lapse rates appear supportive of potentially heavy rain, rather than severe storms, within broader easterly low-level flow.
Isolated thunderstorms may also develop within northwesterly high-level diffluent flow ahead of a digging trough. Weak instability should develop ahead of a surface front, and elevated convection appears possible during the latter half of the period from the upper Great Lakes into eastern Kansas.