textproduct: Columbia

SYNOPSIS

Scattered showers possible this morning and through the day as a cold front passes. Near record temperatures again this afternoon before high pressure and dry conditions return for the start of Thanksgiving week. Rain chances then move back in during the middle of next week.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Scattered light rain showers through the day with an isolated rumble of thunder possible.

- Near record temperatures again this afternoon.

A weak passing shortwave is generating isolation to scattered light showers across the area early this morning. The wave is quite progressive, and showers are moving quickly from west to east. Rainfall amounts should be fairly light, less than one tenth of an inch, with very minimal impacts. Windspeeds should increase toward dawn, and in combination with cloud cover, keep lows this morning quite mild around 60 degrees.

PWATs will continue to increase today ahead of a cold front with persistent west/southwest flow aloft. As higher PWATs shift east, a break in shower activity is expected, allowing for some clearing and warm advection to boost temperatures into the upper 70s and low 80s. At the same time, forecast MUCAPE values may approach 500-1000 J/kg and increase our chances briefly for an isolated thunderstorm or two this afternoon along the front. Timing may be a factor though, with the bulk of moisture perhaps east of the area before peak heating/greatest instability. Overall this should limit coverage of convection, and severe weather is not anticipated. The front pushes through the forecast area this evening, with drier and cooler air filtering in behind it. Winds will turn out of the west to northwest, with PWATs falling below 1". Lows may be limited somewhat by lingering cloudiness, but will still fall into the low to mid 50s.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Key message(s):

- Cooler and dry for Sunday and Monday.

Following the frontal passage late Saturday evening, cool and dry advection will kick in from the north throughout Sunday and into early Monday. Temps and dew points will return back to average with mostly clear skies both Sunday and Monday as the trailing surface high moves overhead. By late Monday, the high will shift offshore, heights will rise aloft, and southeasterly flow with notable moisture return will develop. So cloud cover and PWAT's will increase quickly as we move into Tuesday morning.

LONG TERM /TUESDAY THROUGH FRIDAY/

Key message(s):

- Rain chances continue for mid-week with a notable warming trend.

Ridging aloft will continue to amplify Tuesday over our area, as the slow moving cutoff low in the western CONUS steadily ejects eastward. Broad southerly component flow will increase Tuesday with temps rising back above average and PWAT's quickly climbing over 1.0". A mix of guidance solutions then play out for how quickly, and how far north, the ejecting trough pushes; ECE has tended to be more progressive with moisture advection compared to the slower NAEFS solutions. This yields some notable differences in total QPF, but not necessarily what is intuitive. The more progressive ECE mean brings a widespread 0.75-1.25" over our area while the slower GEFS occludes the strongest WAA and moisture convergence to our northwest and results in 0.75" or less for the area. Regardless of how this front plays out, the front will eventually push through by later in the week bringing a much cooler airmass and high probabilities of below average temps Thursday onward.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

Mainly VFR conditions, with some CIG restrictions possible later this morning.

ISOLD-SCT -SHRA are possible at the terminals this morning, but confidence in restrictions due the precip is low. However some MVFR CIGS are possible a bit later, around 11z-16z with the highest confidence at AGS/DNL. Relatively light winds overnight from the southwest should pick up to around 10 knots by 14z-15z, along with gusts to 20 knots through the afternoon. The front passes later this evening, around or maybe a bit after 23/00z, and winds will veer to the west/northwest with gusts decreasing.

EXTENDED AVIATION OUTLOOK...No significant aviation concerns expected through early next week.

CAE WATCHES/WARNINGS/ADVISORIES

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