FXUS62 KCAE 070036 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 836 PM EDT Mon May 6 2024 .SYNOPSIS... Scattered showers and thunderstorms continue through the early this week as multiple disturbances move across the region. A lull in activity is anticipated for midweek, with increasing chances of showers and storms towards the end of the week. Expect generally above average temperatures through the latter half of the week before transitioning to near or slightly below average next weekend. && .NEAR TERM /UNTIL 7 AM TUESDAY MORNING/... The mid-upper level trough responsible for driving some scattered-widespread convection is shifting across the TN Valley and we have generally stabilized across the Midlands and CSRA behind these showers-storms for the time being. Based on the current satellite obs and hi-res guidance however, abundant moisture, still relatively steep lapse rates, and forcing from the mid-upper level trough will continue drive showers-storms as weak destabilization and conditional unstable profiles aloft; the HRRR has been in consistent agreement run to run in widespread shower-storm activity overnight between 06-12z, mainly remaining in the Midlands and Upstate. Low level lapse rates will become isothermal however and should generally prevent surface based convection, therefore greatly reducing severe threat. But forcing from the upper trough and potentially strong cold pool development could help anchor a few storms to the surface layer still. So PoPs remain fairly high overnight, with some likely elevated thunderstorms but the severe threat will lessen somewhat. Heavy rain and flooding looks to be the primary threat, especially in areas that saw heavy earlier, as PWAT's remain high (around 1.5-1.75"). && .SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... Tuesday and Tuesday night: A shortwave trough is forecast to continue progressing eastward and out of the forecast area in the morning hours. There could be a lingering shower or thunderstorm in the Pee Dee early on in the day, but should be quick to exit the region if there are any showers. Behind the shortwave, relatively flat ridging moves over the region, allowing temperatures to rise to above average for this time of year. A weak shortwave is forecast to move through the broader ridge during the afternoon, mainly to the north of the forecast area. With moisture expected to remain relatively high through the day (PWATs around 1.5"), a few showers or thunderstorms could develop, mainly for the northern portions of the forecast area. Other areas should remain dry for the day. Overnight lows should remain above average as well. Wednesday and Wednesday night: Another warm day is expected on Wednesday as the broad ridge remains over the region. However, a larger scale upper trough is forecast to begin moving toward the Southeast from the Upper Midwest. Another shortwave is forecast to slide through the area in between the ridge and trough, which could spark more showers and thunderstorms. A majority of the energy from this shortwave looks to stay north of the area, but some guidance extends the energy into our forecast area. Forecast soundings from multiple models do support the potential for strong thunderstorms, mainly north of I-20. The soundings near Columbia indicate a bit of a warm nose around 700 mb, which should hinder convection. As you go north toward the Charlotte area, this warm nose becomes less pronounced, which is why PoPs are a little higher there and the potential for stronger storms is greater there as well. && .LONG TERM /THURSDAY THROUGH MONDAY/... Thursday and Thursday night: The larger scale trough continues to move eastward while a developing surface low and associated cold front move towards the area on Thursday. Another shortwave is forecast to move through the region, allowing for more convective activity in the afternoon and evening hours. With the larger scale trough approaching, temperatures aloft begin to cool, which would lead to eroding that aforementioned warm nose around 700 mb. This would lead to a higher chance for severe weather. Confidence has increased a bit in this scenario as the various model guidance has come into better agreement. That said there still remains some timing and strength differences, which would affect the overall severe weather potential for the region. Friday through Monday: Another round of storms looks possible Friday morning as some guidance indicates an MCS moving through the Deep South will make its way into the Southeast during the morning hours. There remains plenty of uncertainty with this scenario, so confidence is on the lower side as of now (~20%). After that and a cold front pass, more tranquil weather is forecast for the weekend into early next week. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... High confidence in VFR conditions through the evening hours then possible restrictions in early morning convection and stratus around 12z. Afternoon convection has generally shifted away from the terminals and do not expect any issues this evening with convection. Some lingering mid level clouds through 02z-03z then some clearing expected overnight. Abundant low level moisture remains in place and some radiational cooling likely will result in some vsby restrictions at fog prone AGS, less confident other terminals. Hi-res guidance suggesting a line of convection moving southeastward through the Midlands along and north of I-26 during the 09z-14z time frame so included a tempo group for TSRA and cig/vsby restrictions. Otherwise, expect VFR conditions with light southerly winds overnight picking up from the southwest by 15z to around 8 to 10 knots with some afternoon gusts approaching 20 knots. EXTENDED AVIATION OUTLOOK...Morning fog/stratus less likely on Wednesday with drier air over the region. The extended will be active, with mainly diurnal convection each day. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$