textproduct: Columbia

SYNOPSIS

Dry weather and warm conditions continue today. Another weak front may bring slightly cooler conditions Sunday, but with more dry weather. The passage of a strong cold front early next week brings much colder conditions to close out the year, though the chance of rain during the next seven days is relatively low.

UPDATE

An area of dense fog has been observed mainly across Lancaster County this morning, via both surface and satellite observations. A Dense Fog Advisory is now in effect for this area through 9 AM EST.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Near record temperatures expected this afternoon.

Low level moisture remains high over the region with dewpoints in the low to mid 50s and relative humidities generally above 75%. Some patchy fog remains possible on and off this morning as temperatures drop given some breaks in the clouds. Otherwise, for the rest of today, strong upper ridge builds back over the area with the axis shifting eastward. Surface high pressure builds over the area from the south, which should push a lingering front away from the region. Temperatures will warm up this afternoon to near record highs, generally in the mid to upper 70s for most locations. The record high at both CAE and AGS today is 77 degrees, well within reach given warm downsloping. Temperatures tonight remain above normal.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Key message(s):

- Weak backdoor front will drop temps a bit Sunday.

- Strong cold front moves through Monday afternoon, gusty winds but low precip chances.

Much like Friday, a weak shortwave moving quickly through the ridge axis will drive a subtle low pressure system through the Mid- Atlantic. This will push a weak backdoor front down into the area, much like we saw on Friday. Combine this with some enhanced cloud cover, we will see another notable temp gradient across the area with the CSRA still remaining in the 70's and the northern Midlands in the 50's.

The strong ejecting Pacific trough will quickly push eastward as we move into Sunday, developing a very strong low pressure system over the Great Lakes. The associated surface front will then dive across the southeastern US late Monday. While the cold advection and wind field is quite strong, the overall lack of moisture convergence means this will be a mostly dry front; PWAT's barely climb above 1.0". So besides a few showers, the winds will be the main feature with gusts from the southwest early Monday over 30 mph, then turning westerly behind the front in the evening with some gusts around 40 mph. High temps Monday ahead of the front will likely top out in the 70's thanks to the strengthening southwest flow, before the strong cold advection of 3-6 C/hr develops overnight. Low temps Tuesday morning will be the coldest in awhile as a result with temps in the 20's.

LONG TERM /TUESDAY THROUGH FRIDAY/

Key message(s):

- Below average temps expected throughout the long term period but otherwise calm weather.

Troughing across the eastern US will dominate the long term period next week with daytime highs running 10-15 F below average. Overnight lows however will not be as anomalously cold due to elevated winds with no ideal radiational cooling nights. Northwesterly flow aloft will dominate, keeping PWAT's below 0.5" throughout the period and therefore no notable rain chances expected.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

VFR conditions generally expected through the forecast period.

Some low level moisture is lingering over the area and may allow for some patchy fog/stratus concerns. Not much has materialized thus far, so confidence remains low at the terminals, but maintained TEMPO groups for MVFR VSBYS through 13z-14z. Conditions should then quickly improve back to VFR. Otherwise, mid and upper level clouds with bases around 4- 6kft MSL this morning. Clearing to SKC this afternoon into this evening. SFC winds light and variable through daybreak, then shifting more to the west- northwest after 15z with speeds around 5 to 8 knots. Cloud cover increases tonight ahead of the next system, with restrictions becoming more likely particularly after 06z.

EXTENDED AVIATION OUTLOOK... Low level moisture could bring morning fog or stratus again on Sunday and on Monday ahead of a strong cold front before drier air filters in on Tuesday.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Dense Fog Advisory until 9 AM EST this morning for SCZ115-116. GA...None.