1PM Day 3 Convective Outlook for Saturday, February 28. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Thunderstorms will be possible across the Florida Peninsula and across northern California and southern Oregon on Saturday. Additional thunderstorms may be possible across the Southern Plains Saturday evening into early Sunday morning.
Synopsis
A persistent northwest flow regime will continue across the CONUS well into the weekend with continued upper ridging over the Southwest/West Coast and the maintenance of a long-wave trough over the East. Within this flow regime, several embedded disturbances will support areas of convection, namely over the Florida Peninsula and across northern California and adjacent portions of OR and NV. Isolated thunderstorms are also possible across parts of the southern Plains into the Ozark Plateau within a low-level warm advection regime.
FL Peninsula
Isolated to scattered thunderstorms appear likely through the day along the FL Peninsula as ascent associated with a de-amplifying upper wave persists over a buoyant and weakly capped environment. Although some hodograph elongation is noted in recent forecast soundings, confidence in updraft intensity is limited due to modest mid-level lapse rates and weak low-level convergence/forcing for ascent. Any appreciable severe threat would most likely manifest along the FL east coast where sea-breeze convergence may focus thunderstorm development, but confidence in this potential is too limited at this time for risk probabilities.
Oklahoma into the Ozark Plateau
Zonal flow across the central Rockies will promote steady lee troughing along the High Plains through late Saturday night. In response, warm/moist air advection is expected to increase through the lowest few kilometers as a plume of low to mid-50s dewpoints spreads north into OK within a southerly flow regime. Isentropic ascent within a weak deformation zone at around 850 mb will likely be the impetus for thunderstorm development within the destabilizing air mass by Saturday evening. The quality of moisture return/destabilization remains uncertain due to notable spread in guidance, which lends low confidence in overall storm coverage and intensity at this time. However, thunder probabilities were maintained/introduced where agreement between long-range ensembles and extended-range CAMs appears greatest.
Northern CA into OR and NV
A shortwave trough is forecast to crest the axis of the persistent upper ridge in place along the CA coast. Cold mid-level temperatures under the upper low coupled with an influx of Pacific moisture through a deep layer should support convective elements within broader precipitation bands. Forecast soundings suggest buoyancy profiles will remain too limited to support intense convection, which should preclude a severe threat.