textproduct: Columbia

SYNOPSIS

Patchy fog in areas near water through daybreak. High pressure then continues to bring cool and dry conditions to the area today. The next storm system approaches late today into tonight with another period of moderate to potentially heavy rainfall on Friday. Unsettled weather continues into the weekend and potentially into early next week.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Patchy fog, dense at times, possible overnight, especially near bodies of water. - Dry and cool through much of the day, with rain spreading across the area this evening into tonight.

Through daybreak: Current satellite imagery shows that fog is developing over lakes and rivers given the clear skies. Local webcams and observations indicate pockets of this fog is pretty dense with visibilities below 1 mile at times. Will continue to monitor trends with this fog for the need of an SPS or dense fog advisory through the night.

Today and Tonight: A surface low developing over Mexico and western Gulf is forecast to move toward the Southeast today aided by an upper trough digging into the Southern Plains. This trough keeps flow aloft southwesterly, allowing for moisture and some warm air advection to move into the area today. As a result, we are looking to be a few degrees warmer than Wednesday, but under mostly cloudy skies. Shortwave energy moving through the upper flow starts to bring some forcing to the area that is expected to bring shower activity this evening into tonight. Latest hi-res guidance shows some rain possibly reaching the CSRA this afternoon. However, model soundings indicate that there is a lot of dry air to overcome. Therefore, this forecaster is not highly confident in rain occurring, but have gone with a slight chance for rain, with a peak of about 25% chance in the lower CSRA, where forcing does look a little better. That said, if any rain does fall in the afternoon, I expect it to be light. As better forcing moves in overnight, more widespread and consistent rain is expected to move into the region overnight from the southwest to northeast. Some moderate rainfall is possible near daybreak Friday, mainly over the eastern portions of the forecast area.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/

Key message(s):

- Cool temperatures with widespread rain expected Friday. - Chances of rain continue Saturday favoring the southeast Midlands and moderate to heavy at times.

A cold but moist air mass will be in place on Friday with high pressure centered over New England riding into the Carolinas. Ensemble PWATs will be 175-200 percent of normal Friday into Saturday supporting widespread rainfall across the forecast area as isentropic lift increases with southwesterly flow atop the low level wedge ahead of an approaching upper trough. Rain is expected to be ongoing at the beginning of the period and reinforcing the developing wedge with well below normal temperatures expected on Friday with highs ranging from the lower 40s north to around 50 in the southeast Midlands, with possibly falling temperatures late Friday. Any winter weather concerns appear to be confined north of our area in northern and western NC, although expecting a cold rain across the area. The combination of warm advection aloft and some shortwave energy will support moderate to heavy rain at times which will continue into Saturday. The best chances of rain on Saturday shift a bit south favoring the area along and south of the I-20 corridor. There is a 50% or higher chance for most locations to receive an inch of rain through Saturday night and a 20-30% chance of some locations in the southeast Midlands and lower CSRA to receive 3 inches of rain. Minor flooding will be possible but widespread flooding is not expected as the rainfall should be spread out over a long enough period of time. Temperatures on Saturday will continue to be below normal and struggle to get into the lower 50s. Lows both nights expected to be in the 30s to lower 40s.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Key message(s):

- Below normal temperatures continue through the period - Chances of rain continue into Monday then drier weather into mid week

Rain chances remain over the forecast area on Sunday with deep southwesterly flow aloft continuing to feed gulf moisture into the region with warm advection and weak shortwave energy moving through the mid level flow while the weak wedge remain in place at the surface. Chances of rain lower on Monday but cannot be eliminated with the ensembles showing an upper trough moving over the forecast area. Rainfall total not expected near as high during this period compared to Fri/Sat. A cold front will move through the forecast area in the wake of the passing shortwave with cold high pressure building into the Carolinas Monday night. NAEFS mean 500mb heights are forecast to be in the 10th percentile early next week and EC EFI hinting at anomalously low temperatures so it appears the below normal temperatures and cool pattern will persist.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Patchy fog brings potential for restrictions through daybreak followed by VFR conditions through much of the rest of the TAF period.

Patchy fog has developed along lakes and rivers, which has brought visibility down to 1SM or lower to OGB and AGS at times. Expect this to continue through daybreak. Confidence is a little lower that CAE/CUB/DNL will see visibilities that low, but will continue to monitor and amend TAFs as necessary. Improvements in visibilities are expected after about 12z-14z, becoming mainly VFR through the remainder of the TAF period. Mid-level ceilings are expected to move into the region through the day. There is a small chance (<20%) for light rain at AGS/DNL (and lesser at OGB) from about 18z-00z today, but not including in TAF at this time due to low confidence. Ceilings begin lowering after about 22z-00z or so, but remain in VFR until possible very late in the TAF period. Rain is also anticipated to be on the doorstep toward the end of the TAF period and may start falling at AGS/DNL at the tail end, but will add any RA in the next scheduled TAF as needed. Generally west to southwest winds around 5 kts can be expected through the daylight hours before diminishing after about 00z.

EXTENDED AVIATION OUTLOOK... Restrictions are possible again Friday as rain spreads across the area. More restrictions due to rain showers could also be possible this weekend.

CAE WATCHES/WARNINGS/ADVISORIES

SC...None. GA...None.