11AM Day 2 Convective Outlook for Thursday, February 12. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Severe thunderstorms are not expected on Thursday.
Synopsis
A deep, positively tilted upper trough is expected to extend from the northern Intermountain West southwestward off the central CA Coast and into the eastern Pacific early Thursday. This trough is forecast to progress slowly southeastward throughout the day, while trending towards a more neutral tilt as a strong shortwave trough rounds its base. Another embedded shortwave trough is expected to move southward along the central CA coast before pivoting more southeastward towards southern CA late Thursday/early Friday. Overall evolution of this system will likely result in troughing from the western Great Basin into the west-central Pacific by 12Z Friday.
Cooling mid-level temperatures are expected from the Great Basin into the central Rockies downstream of this deepening trough. Additionally, persistent southwesterly flow aloft will contribute to some low-level moistening beneath these cooling mid-level temperatures. Combination of these factors will result in modest buoyancy and deep/persistent enough updrafts for isolated lightning flashes. Highest coverage is expected across north-central UT.
Surface ridging is expected across much of the central and eastern CONUS early Thursday, although a weak surface low will likely be over southeast CO. This low may deepen slightly throughout the day while also dropping gradually southward in northeast NM and the northwest TX Panhandle. Some modest moisture return is anticipated east/southeast of this low across central/east TX and the Lower MS Valley, with low 60s dewpoints forecast along the TX Gulf Coast by Friday morning. However, warm temperatures aloft will preclude deep convection within this modifying airmass.