textproduct: Columbia

SYNOPSIS

A much colder air mass builds in behind an exiting cold front, with chilly temperatures tonight. Near to below normal temperatures will then prevail through much of next week. The chance of rain during the next seven days is low, less than 20 percent.

NEAR TERM /UNTIL 6 AM MONDAY MORNING/

Key message(s):

- Lake Wind Advisory and Fire Danger Statement continue until 7pm this evening.

- Chilly temperatures move in tonight.

The base of the upper trough is beginning to swing east of the region this evening, taking with it the 30-35 kt LLJ that was in place much of the day. At the surface, high pressure is beginning to near the FA from the west with a loosening pressure gradient. Due to this, winds have been weakening over the past hour with gusts already under 25 mph generally and these will continue to weaken overnight tonight. Due to this, the Lake Wind Advisory should be allowed to expire at 7pm as scheduled. Though, a very dry airmass remains in place, weakening winds will allow the Fire Danger Statement in effect until 7pm to expire as well. Strong CAA is now pushing into the region behind Saturday's system and this should drive low temperatures that will be rather chilly tonight, in the mid to upper 20s, as mostly clear skies return into Monday.

SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/

Key message(s):

- Cool, high pressure builds in Monday through Tuesday night.

Following the cold, dry advection on Sunday, high pressure will quickly fill in for the first half of the week with strong northwesterly flow aloft. Temps will run a bit below average as a result for both overnight lows and daytime highs especially on Monday. Winds will be light as the surface high moves overhead and no precip is expected through Tuesday.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Key message(s):

- A series of sharp troughs will dig across the area Wednesday and then again over the weekend.

Like we saw on Sunday, the current synoptic pattern of mostly dry fronts and trough passages every 3-4 days will continue; this pattern is broadly driven by the decaying pacific jet positioning and consequent downstream ridging in the western US. So a quickly strengthening trough will dig across the central US and drive a surface low and front over our area Wednesday. While the trough and height falls will be notable, moisture advection ahead of the front is not very impressive. So precip chances increase Wednesday and early Thursday, but only ~20-30% for the area. Behind the front on Thursday, strong gusty winds are expected and could be close to wind advisory criteria with some gusts over 40 mph. This 3-4 day synoptic pattern will then continue with a relaxing trough Friday into Saturday and then another digging shortwave on Sunday with increasing rain chances.

AVIATION /00Z MONDAY THROUGH FRIDAY/

VFR conditions prevail through the period.

It has been quite windy out there this afternoon! A strong pressure gradient behind the cold front led to winds that were a bit stronger than previously forecast, with frequent gusts 35-40 mph at all sites. The winds have already begun to relax across the area as surface high pressure is rapidly approaching the area from the west. This is forecast to begin overspreading the area after around 06z, with winds becoming light and variable from there. The airmass is extremely dry, with GOES Derived PWs less than 0.25" moving into the area. As such, it is likely that skies remain clear throughout the period. Winds are expected to remain variable throughout as the surface high shifts over and through the area tomorrow.

EXTENDED AVIATION OUTLOOK...A mid-week system moving through could bring brief restrictions.

FIRE WEATHER

Fire weather concerns remain elevated this afternoon and early evening due drying and RH values dropping to near critical values, along with strong wind gusts over 30 mph with deep mixing. We have issued a Fire Danger Statement for our entire forecast area through this afternoon and early evening. In addition, the SC Forestry Commission has issued a Red Flag Fire Alert for increased fire danger discouraging burning from the Midlands to the coast.

Another strong front is expected mid-week, so depending on precip amounts, another round of fire danger concerns may occur again Thursday.

CAE WATCHES/WARNINGS/ADVISORIES

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