Area Forecast Discussion
Issued by NWS Columbia, SC

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KCAE 220650 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 150 AM EST Wed Nov 22 2017 .SYNOPSIS...
-- Changed Discussion --
An area of low pressure will shift NE offshore the NC coast today, with light rain exiting our forecast area early this morning. Morning fog and low cloudiness is expected to give way to decreasing cloudiness this afternoon as drier air works into the region behind a weak back door front. A series of low pressure systems will track from the Gulf of Mexico NE across Florida and offshore the Carolinas late Thursday through Friday night, providing variable cloudiness along with a slight chance of light rain, mainly southern and eastern areas. A dry cold front will cross the region Saturday night, with high pressure building into the region behind it through early next week.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Mean upper trough axis stretching from the Great Lakes region into the Gulf of Mexico. Upper disturbance and weak surface low will push off to our NE this morning. Areas of light rain associated with the system will push NE out of our forecast area (FA) early this morning. Moist low levels due to earlier precipitation plus some enhanced cooling due to drier air moving in aloft, seen on satellite water vapor imagery, providing dense fog potential. Issued dense fog advisory for the CSRA/W Midlands. Will monitor for possible expansion eastward later this morning. Otherwise, expect drier air to work into our region this afternoon and tonight behind a dry back door front.
-- End Changed Discussion --
&& .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
Upper troughiness will continue to extend from the Midwest south into the Gulf of Mexico. Upper energy will lead to a series of low pressure areas developing in the Eastern Gulf of Mexico and tracking NE across FL and offshore the Carolinas, while surface high pressure builds into the Mid Atlantic. Some uncertainity in play which reduces confidence on specifics. It still appears that the bulk of moisture will remain south of our FA through the period. However, considerable uncertainty in play as models have trended a little slower and farther south with the first wave and associated moisture, and are trending stronger and farther north with the next low and associated moisture. Due to uncertainty, blended ongoing forecats with latest guidance consensus, which provides a slight chance of light rain mainly southern/eastern areas.
-- End Changed Discussion --
&& .LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
Northern stream trough will dig into the E CONUS Saturday, providing a drier NW flow aloft. Upper energy and a cold front will move through Saturday night. Current indications are that no siginficiant precipitation will be associated with the system. Dry cool Canadian high pressure will build into the region Sunday through Tuesday.
-- End Changed Discussion --
&& .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... Widespread IFR/LIFR conditions expected early in the forecast period with improvement after 15z. Light rain showers associated with a passing upper disturbance and weak low moving along the coast is pushing away from the terminals early this morning. As the precipitation moves out some mid level dry air is moving atop the moist boundary layer with light to calm winds which is resulting in widespread fog and restrictions. Expect LIFR cigs/vsbys at AGS/DNL 06z-15z with conditions deteriorating at CAE/CUB/OGB by 08z. It may be slow to improve during the day Wednesday with the high moisture remaining under an inversion. However, isentropic downglide combined with diurnal mixing should eventually help raise ceilings and visibilities. Forecasted a return to VFR conditions a little later than most of the guidance because of the expected northerly surface wind and inversion. EXTENDED AVIATION OUTLOOK...A frontal zone near the coast with a series of low pressure centers moving northeastward may help support MVFR or IFR conditions at times through Thursday. && .CAE WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
GA...Dense Fog Advisory until 10 AM EST this morning for GAZ040- 063>065-077. SC...Dense Fog Advisory until 10 AM EST this morning for SCZ018-020- 025-026-030-035.
-- End Changed Discussion --
&& $$

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