Area Forecast Discussion
Issued by NWS Columbia, SC

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KCAE 190751 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 351 AM EDT Tue Mar 19 2024 .SYNOPSIS... Some freezing temperatures are possible early this morning across the northern and western Midlands. Dry weather and warmer temperatures follow during the middle of next week. Our next storm system is expected to develop across the southeast late in the week and bring increased chances of rain Friday and Saturday. && .NEAR TERM /THROUGH TONIGHT/... At upper levels, a Rex block is in place over the W CONUS, with a deep trough over the E CONUS, funneling cool and dry air into our region. A tight pressure gradient between the Canadian surface high to our west, and a front and low pressure offshore, resulting in breezy conditions accompanying the cold advection. No frost threat due to wind and dry air, but the cold advection alone is expected to result in near freezing temps early this morning over our northern forecast area (FA), where a Freeze Warning remains in effect. Some indications of decreasing wind speeds later tonight over land areas, but higher wind gusts over warmer area lakes expected to continue, so a Lake Wind Advisory remains in effect until 8 am. The surface high to our west will shift south towards the Gulf coast through tonight, while NW flow aloft, and associated lee side surface trough, will set up to our north, keeping a fairly tight surface pressure gradient over our region. This is important as any significant wind would preclude a frost threat for tonight. Despite guidance consensus min temps in the upper 30s, dry air and wind expected to preclude the need for a Frost Advisory. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
-- Changed Discussion --
Wednesday and Wednesday Night: Persistent northwesterly flow aloft continues on Wednesday with some confluent 500mb flow resulting in subsidence and plenty of sunshine across the forecast area. Surface high pressure remains south of the area with southwesterly flow providing warm advection and combined with sunshine should support high temperatures in the lower to mid 70s. A weak and dry frontal boundary is expected to push southward through the forecast area late Wednesday night during the predawn hours, bringing mainly just some mid and high level clouds to the region. Winds will shift to the northeast behind the front by early Thursday morning. A well mixed boundary layer should limit radiational cooling Wednesday night and expect warmer temperatures with overnight lows in the lower to mid 40s. Thursday and Thursday Night: The surface front that pushed through the region early Thursday morning is expected to stall to our south across southern GA on Thursday with easterly flow across our area with the center of high pressure over the Mid- Atlantic coast. Meanwhile, further west an upper trough over the southern Plains will gradually shift eastward into the lower Mississippi Valley Thursday night. Ahead of this system, warm and moist advection will commence with increasing south- southeasterly 850mb flow over the top of surface ridging. This should result in isentropic lift developing over the forecast area bringing the possibility of light showers to the region late Thursday night. Temperatures should continue to be warm across the CSRA and southeast Midlands with cooler temperatures to the north with highs ranging from the mid 60s to lower 70s. Increasing clouds and persistent easterly flow Thursday night will prevent strong radiational cooling and expect lows to range from the mid 40s north to around 50 in the CSRA.
-- End Changed Discussion --
&& .LONG TERM /FRIDAY THROUGH MONDAY/...
-- Changed Discussion --
Active weather returns to the area on Friday as the southern stream upper trough moving east through the MS Valley crosses the forecast area Friday night into Saturday. The main change from yesterday`s thinking is that rain may linger a bit more into Saturday as uncertainty has increased a little compared to yesterday as the EC ensemble has trended a bit slower and more amplified with the upper trough, closing it off as it moves offshore Saturday night, while the GEFS ensemble is more progressive and a bit faster moving the upper trough through the area. Held on to higher pops on Friday night and keep some pops across the area through the day Saturday. PWATs rise significantly on Friday to a peak around 1.5 inches or nearly 200 percent of normal by Friday night. The initial forcing with this event begins as warm advection, isentropic overrunning with some possible wedge conditions developing on Friday (especially in the northern and western Midlands) then the upper divergence associated with the upper trough moves through Friday night forcing possible moderate rain at times, although there are some signals of possible Gulf Coast convection which could negatively impact rainfall totals. Relatively high confidence in little to no instability present so no mention of thunder at this time. Cooler and drier high pressure builds over the area Sun/Mon in the wake of departing upper trough with weak shortwave ridging over the forecast area and surface high pressure building over the region. Temperatures during this period are expected to be variable with cooler temps on Friday followed by a return to near normal temps on Saturday then lower confidence in temps at the end of the period with large ranges in ensemble guidance.
-- End Changed Discussion --
&& .AVIATION /08Z TUESDAY THROUGH SATURDAY/... VFR. Cool and very dry air continues to work into the region. This, along with wind, will preclude any fog/stratus concerns. Breezy winds in the near term, with decreasing speeds later this morning. Winds expected to pick up again during the mid to late afternoon. Numerous scheduled prescribed burns for today may provide some locally reduced VSBYs in smoke over some areas this afternoon and early evening. EXTENDED AVIATION OUTLOOK...No significant impacts to aviation expected Tuesday night through Thursday. Some CIG restrictions may develop late Thursday night. Rain and associated restrictions Friday into early Saturday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...Lake Wind Advisory until 8 AM EDT this morning for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. Freeze Warning until 8 AM EDT this morning for SCZ016-018-020- 021-025-026-115-116. GA...Lake Wind Advisory until 8 AM EDT this morning for GAZ040- 063>065-077. Freeze Warning until 8 AM EDT this morning for GAZ040-063-064. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.