SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Dec 03 2020 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE WESTERN AND CENTRAL FL PANHANDLE...AND ACROSS THE COASTAL CAROLINAS... ...SUMMARY... Isolated severe thunderstorms are possible portions of the Florida Panhandle Friday afternoon, and across the coastal Carolinas early Saturday morning. ...Synopsis... A positively tilted shortwave trough is forecast to extend from the middle OH Valley into north TX early Friday morning. This shortwave is then expected to progress quickly eastward while pivoting to a neutral and then negative tilt. By early Saturday morning, the expectation is for this shortwave to be over the Mid-Atlantic States. Surface low associated with this shortwave will likely be centered near coastal MS/AL early Friday morning before quickly moving northeastward into the Mid-Atlantic ahead of its parent shortwave. As it does, an attendant cold front will sweep eastward/southeastward across eastern portions of the Southeast, the FL Panhandle, and much of the Mid-Atlantic. Two areas of potential severe weather are possible, one across the FL Panhandle Friday afternoon and the other over the central and eastern Carolinas early Saturday morning. ...FL Panhandle... Low to mid 60s dewpoints are expected to be in place ahead of the cold front Friday morning into Friday afternoon. Abundant cloud cover is expected, tempering daytime heating, and lapse rates will be poor. Consequently, despite favorable low-level moisture, instability will be modest (i.e. MLCAPE less than 750 J/kg). Most of the better flow aloft and vertical shear will be displaced north of any instability and/or behind the front. However, there appears to be a relatively narrow window where instability and vertical shear will overlap enough to promote at least low-probability severe potential across the western/central FL Panhandle Friday afternoon. In this area, any more robust and persistent updraft could produce an isolated damaging wind gusts and/or brief tornado. ...Mid-Atlantic... The shortwave is expected to mature as it continues eastward into the Mid-Atlantic region, with this maturation contributing to an increase in low to mid-level flow throughout its eastern periphery. This enhanced flow aloft will spread into the central and eastern Carolinas from 06Z to 12Z Saturday. Additionally, favorable onshore trajectories will result in modest moisture advection, with dewpoints likely in the low to mid 60s. As a result, there will likely be enough instability and shear for a few supercells ahead of the front, as well as strong storms along the front. Damaging wind gusts appear to be the greatest threat, but a tornado or two is also possible. Higher wind probabilities may be needed in later outlooks if the probability for slightly greater instability increases. ..Mosier.. 12/03/2020
There’s more click here.