textproduct: Columbia

SYNOPSIS

Above normal temperatures and mainly dry conditions are expected to continue through the weekend, though Friday will see a brief cooldown. The passage of a strong cold front early next week will lead to much colder conditions to close out the year, though the chance of rain during the next seven days is low.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Above normal temperatures continue again today.

High pressure will still be in control again, with warm advection pattern in place. Clouds should be scattered out by this afternoon, allowing additional sunshine to bring another warm day across the region. High temperatures will once again feel much more like Spring, with readings in the mid to upper 70s. These should top out just below our record highs for Christmas day. Dry conditions will continue into tonight. Later tonight, a weak front will push towards the forecast area from the north as high pressure builds across southeastern Canada. Guidance continues to show this front southward dry, so no rain expected overnight at this time. Overnight lows remaining mild once again, with values between 50-55 degrees expected.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/

Key message(s):

- Cooler across the northern Midlands with a few showers around.

A low amplitude mid-level shortwave will eject out of the strong Pacific trough, round the broad ridging in the central US, and then dive into the Mid-Atlantic. A weak, quick moving low pressure will reflect at the surface with some subtle moisture convergence downstream. As a result, some enhanced cloud cover and a few showers will extend down into NC, maybe into northern SC; PWAT's are only around 1.0", so any rain will light with minimal accumulation. This will set up a sharp temp gradient somewhere near the northern border of our forecast area, with temps across NC topping out in the 40's but down into the CSRA, temps should climb again into mid-70's.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Key message(s):

- Deep ridging and very warm temps will build back in for Saturday and Sunday.

- Another mostly dry front Monday will usher in a much colder airmass Tuesday onward.

Behind the quick moving shortwave from Friday, deep ridging and generally dry air will build back into the region. Temps will return to well above average for the entire area, with highs again in the 70's Saturday and Sunday (15-20 degrees above average, near record highs). Eventually the deep and persistent Pacific trough will eject eastward, driving a strong surface low and cold front into the eastern US. Guidance has slowed down a little with the progression of this trough ejection, as is pretty typical, with the associated cold front now swinging through late Monday and into Tuesday. The airmass behind this front looks anomalous in the opposite direction, with temps running 10-15 degrees below normal. NAEFS and EC EFI highlight this whole period well with a prominent swing from near record highs to well below average by the middle of next week.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Mainly VFR conditions expected for the majority of the TAF period.

Satellite showing scattered to broken mid-level cloudiness across much of the Midlands of SC and CSRA of GA early this morning. Guidance continues to keep cloud ceilings vfr through this morning, with bases around 6kft being indicated. Have generally kept with that trend at all sites. After sunrise, clouds will continue to scatter out for the remainder of the TAF period as southwesterly winds increase to around 8-10 kts, with a few higher gusts of 15-20 kts in the afternoon. Winds will decouple by sunset, remaining southwesterly with speeds less than 5 knots. Late tonight towards 08z, guidance is hinting at potential for mvfr visibilities developing.

EXTENDED AVIATION OUTLOOK... High low-level moisture and a passing disturbance may bring ceiling restrictions Friday, before morning fog or stratus could occur into this weekend.

CLIMATE

Daily Record High Temperatures for CAE and AGS:

Christmas Day Records: - Columbia: 79 F (1955) - Augusta : 81 F (2015)

CAE WATCHES/WARNINGS/ADVISORIES

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