Area Forecast Discussion
Issued by NWS Columbia, SC

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000 FXUS62 KCAE 281145 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 645 AM EST Tue Feb 28 2017 .SYNOPSIS... A warm southerly flow between offshore high pressure and an approaching cold front will continue through Wednesday. The cold front will move through the forecast area Wednesday night. Thunderstorms may be associated with the front late Wednesday afternoon and night. It will be windy just ahead of the front Wednesday. Cooler conditions will follow the front for the end of the week. && .NEAR TERM /THROUGH TONIGHT/... A weak warm front will bring low clouds and areas of fog early this morning. The front should dissipate later this morning and with heating and mixing plus just shallow moisture expect considerable sunshine and a warm day. The temperature guidance was consistent with highs mainly in the lower 80s and just below records for the date. Moisture has become shallow behind the mid-level shortwave trough that has moved through the forecast area. The models indicate moderate instability today. The NAM has surface-based LI values -5 to -6 but with just shallow moisture and the dissipating surface feature the thunderstorm chance is very low as supported by the NAM, GFS, and ECMWF MOS plus high-resolution models. The shower and thunderstorm chance should remain very low tonight with continued shallow moisture and much of the lift associated with a mid-level shortwave trough staying north of the forecast area. Low-level moisture and weak isentropic lift may lead to stratus and fog tonight with stratus favored because of boundary layer wind. Warm advection and mixing should help hold up temperatures. The temperature guidance was close with lows around 60. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... The main issues Wednesday will be windy conditions ahead of a cold front and possible severe thunderstorms late Wednesday afternoon and night. The models depict a strong low-level jet ahead of the cold front Wednesday with h85 winds 40 to 50 knots. There should also be strong warming and instability ahead of the front. The NAM displays surface-based LI values around -6. Associated strong mixing should lead to windy conditions. The NAM Bufkit momentum transfer tool supports gusts near 30 knots Wednesday afternoon. A lake wind advisory will likely be needed. Convergence ahead of the front may lead to a band of showers and thunderstorms and with continued high shear and possible moderate instability lingering into the night severe thunderstorms may occur. A limited factor may be mid-level capping as shown by the NAM and GFS during the day Wednesday and diminishing instability with the loss of heating Wednesday night. The SPC WRF indicated a diminishing area of showers and thunderstorms moving into the forecast area Wednesday night. Drying behind the front should dominate Thursday. Leaned toward the higher temperature guidance ahead of the front Wednesday. A near record high for the date should occur. The higher guidance may be better Wednesday night because of mixing associated with the front. Followed the guidance consensus temperature Thursday. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The GFS and ECMWF show dry high pressure building into the forecast area from the northwest through Friday with the high near the area Saturday and off the coast Sunday and Monday. The GFS and ECMWF plus GFS ensemble mean have pops less than 20 percent through Sunday, and 20 percent or less Monday. The MOS indicates the coldest air Sunday with lows near freezing. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... Restrictions in stratus/fog will improve to VFR later this morning. Restrictions will be possible again early Wednesday in mainly stratus. Increased low level moisture associated with a warm front in the area is promoting stratus development this morning. Some of the stratus has become scattered, but satellite imagery shows another area of low stratus that could potentially affect CAE/CUB. Confidence was too low to include. Stratus may linger this morning, but as the warm front pushes north, expect a return to VFR. Cannot rule out an isolated shower this afternoon although chances are much too low to include given limited moisture and weak dynamics. Models indicate potential for stratus and fog beginning around 06Z Wednesday morning. However, a 25 to 30 knot low level jet will promote mixing, so expect mainly stratus development. Winds will pick up out of the south after daybreak to around 5 to 10 knots. EXTENDED AVIATION OUTLOOK...Periods of MVFR/IFR restrictions Wednesday morning through Thursday in unsettled weather with occasional showers and thunderstorms. && .CLIMATE... Records for the date... February 28...AGS 86 set in 1962 CAE 84 set in 2011 March 1.......AGS 85 set in 1997 CAE 83 set in 1997 && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$

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