Area Forecast Discussion
Issued by NWS Columbia, SC

Home |  Current Version |  Previous Version |  Graphics & Text |  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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
587 FXUS62 KCAE 100939 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 539 AM EDT Mon Jun 10 2024 .SYNOPSIS... A slow moving front will sink across the area today with multiple rounds of showers and thunderstorms possible. Drier air will spread into the region mid week as high pressure builds in from the north. Moisture will return to the area late in the week leading to increasing chances of mainly afternoon and evening showers and thunderstorms Friday through the weekend. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Early this morning, ongoing convection will move through the northern half of GA and into the CSRA and central SC. Elevated instability of 500 to 1000 J/kg will continue to support thunderstorms as they move eastward. However with a strong low- level inversion the threat of widespread severe weather is low. The greatest threat will be isolated downburst winds and small hail. CAMs generally show scattered thunderstorms growing into a line of storms as it moves into the forecast area from 09Z to 12Z. Later this morning through tonight, a cold front will slowly drift south through the forecast area. Convergence along the front will serve as the focus for showers and thunderstorms in the moist airmass. PWAT values south of the front will be around 1.75 inches. The RAP shows shortwave energy moving into the CWA from 12Z to 15Z possibly allowing convection to develop along the convergence boundary. The short wave should move east mid morning so expect a brief reduction in convective coverage until the peak heating of the afternoon. Dry air will push into the area from northwest to southeast through the day and evening, but precipitable water remains above 1.5 inches in the southeast Midlands. In the afternoon, convection should develop along and south of the front in the higher theta-e air. sbCAPE values of around 1000 J/kg and 0-6km shear of around 40kts may support organized convection and possibly severe thunderstorms with the highest confidence in southern SC. Confidence in severe weather is also limited by the possibility of mostly cloudy skies limiting instability. Cloud cover will also keep daytime highs in the low to mid 80s for most areas. As dry air continues to push south in the evening, convection should shift south and east of the forecast area. Lows overnight in the 60s.
-- End Changed Discussion --
&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Frontal remains will continue moving south of the forecast area with the upper level trough moving off the coast Tuesday and Tuesday night. This will allow slight drier air in to the region as surface winds will be light from the north. Pwat values will also be slightly less than 1 inch with forecast soundings indicating a subsidence inversion around 750 mb. 850 to 500 mb lapse rates will also be less than 6.0 C/Km so expect some cumulus to develop however vertical development will be limited and showers and thunderstorms are not expected. Little change is expected for Wednesday with upper level heights moderating slightly and the flow becoming more zonal and the surface flow gradually turning easterly through the day while remaining 5 mph or less. Although this will begin bringing moisture back into the area and the subsidence inversion will be less pronounced the mid level lapse rates will again be less the 6.0 C/Km so expect the cumulus which develop to have slightly better vertical development however convection is not expected. High temperatures Tuesday will be in the mid 80s to around 90 and the upper 80s to low 90s on Wednesday. Overnight lows will be in the low to mid 60s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Upper level pattern will remain progressive through the long term with ridging building over the central US and sliding eastward through the weekend with the ridge axis over the area by Sunday. At the surface little change is expected with a weak gradient across the region through Friday then a weak boundary will be moving into the region from the north. This boundary will become increasingly diffuse as it moves into the region however with weak southerly flow advecting moisture into the area expect increasing chances of showers and thunderstorms as the boundary will act as a focusing mechanism. Temperatures will be slightly above to above normal through the long term. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
An area of thunderstorms will work through the forecast area this morning producing periods of heavy rain which will reduce visibility at all TAF sites. This round of convection is expected to push east of the area around or shortly after 12Z. Additional Periods of showers and thunderstorms are expected through 06Z Tuesday. Visibility restrictions in convection will be possible at all TAF sites today but the wide timeframe and limited coverage prevents the forecast confidence to place restrictions in the TAFs. Outside of convection, MVFR ceilings are possible from 12Z this morning to 18Z. Winds will be out of the north in the morning becoming light variable around or after 21Z. Convection is expected to drift south and east of the TAF sites after 06Z Tuesday. MVFR ceilings will once again be possible heading into Monday evening as a surface front shifts south of the TAF sites. While widespread fog is not expected, AGS may experience typical shallow fog. EXTENDED AVIATION OUTLOOK...Early morning fog and/or stratus possible through much of the week, especially Thu and Fri. Diurnal showers and thunderstorms may also bring restrictions at times.
-- End Changed Discussion --
&& .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$