textproduct: Columbia

SYNOPSIS

Dry weather is expected to continue the rest of today and Saturday with near to normal daytime temperatures. A cold front crosses the region Saturday night and Sunday morning ushering in an arctic air mass for Sunday night into early next week. Weak ridging should then allow for air mass recovery by the middle of next week.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Dry with near normal high temperatures this afternoon.

- Overnight lows remain near average tonight.

Upper flow has shifted a bit more zonal today as the base of the trough continues to lift north. Some scattered to broken cirrus are now moving out of the FA, giving way to mostly clear skies as weak high pressure centered over the Florida Peninsula ridges into the area. This should bring continued dry weather today with temperatures that reach near normal (mid 50s to low 60s) as low level flow becomes increasingly southwesterly. This continues tonight where moisture slowly rises into Saturday morning with PWAT's that begin rising to near 0.60-0.70". Increasing moisture should also act to limit overnight lows some tonight toward the mid 30s, though it should still be a bit cool across the northern Midlands and Pee Dee where the low 30s is more likely.

SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/

Key message(s):

- Above average temperatures Saturday with isolated rain chances Saturday night.

Saturday will be a transition day and likely the nicest day of the forecast period. The deep trough across the upper Midwest is forecast to dig into the eastern CONUS as an upstream Ridge axis amplifies and shifts eastward. Sunny skies are forecast across the area for most of the day on Saturday, with southwesterly surface flow common. Near to slightly above normal temps are forecast across the area, with highs in the low to mid 60s. Some upper 60s are certainly possible but lets not get our hopes too high. Clouds are forecast to increase as the front approaches from the northwest with scattered showers potentially overspreading the area late on Saturday night/early on Sunday. Lows should be in the mid to upper 40s.

LONG TERM /SUNDAY THROUGH THURSDAY/

Key message(s):

- Arctic cold front ushers in the coldest air mass of the season.

- An Extreme Cold Watch has been issued this afternoon to highlight the dangerous cold expected on Monday morning, with an upgrade to a Cold Weather Advisory likely with later forecast packages.

The key messages remain unchanged with this period, as bitter cold is forecast to overspread the area Sunday night through Tuesday morning. Forecast guidance remains in great agreement on the overall setup, with strong mid/upper level convergence resulting in a strong surface high pushing southeastward out of the Ohio Valley and into the Carolinas and the Atlantic Coastal Plain. The cold front is forecast to pass through the area between 4p and 8p on Sunday, with strong surface pressure rises resulting in wind gusts of 30+ mph for a few hours. Thereafter, winds will likely remain elevated through the early morning hours of Monday, and with temps falling into the teens, wind chills may range from 8F-15F across the area. Both the NBM and LREF support this strongly. In an effort to better serve the public & partners, we have issued a long lead time Extreme Cold Watch for Sunday night and Monday morning to help advertise the cold more effectively. Tuesday night looks very cold as well, and went with cooler guidance than the NBM as ideal radiational cooling conditions should be present over the area. In general, this looks like a very robust cold snap that could be impactful. Be sure to drip your pipes on Sunday and Monday nights to avoid pipe freezes. And if you have any additional outdoor interests, be sure to protect those as well. Beyond this, temperatures begin moderating on Tuesday as upper level ridging overspreads the area from the west. Temps should get back to near normal values by the end of this period.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

VFR conditions are generally expected through the TAF period.

SCT to BKN cirrus are moving out of the TAF sites late this morning, giving way to mostly clear skies for the afternoon as winds around 5- 9 kts turn out of the southwest through the day. Tonight, winds become light and variable to calm as some more passing cirrus are possible. Potential for restrictions associated with fog are low at this time, though it cannot fully be ruled out at the normal prone sites of AGS/OGB. Much of model guidance and forecast soundings do not support fog tonight, though recent HRRR runs have hinted a couple patches could be possible as low level moisture does slowly increase into Saturday morning. The remainder of Saturday morning see's mostly clear skies and winds that remain out of the southwest, picking up to around 5 kts.

EXTENDED AVIATION OUTLOOK...Patchy fog could be possible into Sunday morning as low level moisture continues to increase and a couple showers could be possible. Widespread restrictions look unlikely after Sunday as very cold and dry air moves in.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Extreme Cold Watch from Sunday evening through Monday morning for SCZ027>031-035-037-038-041-135>137. GA...Extreme Cold Watch from Sunday evening through Monday morning for GAZ065-077.