textproduct: Columbia

SYNOPSIS

Very warm this afternoon, but a backdoor cold front is expected to move through tonight resulting in cooler temperatures for much of the forecast area on Thursday. Near record high temperatures remain possible on Friday ahead of the next system. A few showers or thunderstorms are possible on Saturday with a cold front before high pressure returns for Sunday and Monday.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Warm and dry this afternoon. - Cold front moves through tonight.

Very warm temperatures are being noted across the forecast area with many locations in the upper 70s to near 80 as of 12:30 pm. Moisture is also on the uptick as 60 dew points have reached the central Midlands at this time.

Looking ahead, a cold front currently in the Mid-Atlantic is forecast to sag southward this afternoon into tonight. As it reaches the forecast area tonight, a rogue shower or two is possible in the northern Midlands, but confidence is too low to include in the forecast at this time. In addition, some moisture pooling in the CSRA could produce pockets of fog early tomorrow morning. Despite the cold front moving through tonight, temperatures remain mild across the area, with lows likely in the lower to mid 50s.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Key message(s):

- Cooler behind front Thursday before near record highs are possible Friday.

- Rain chances increase late Friday night.

Thursday and Thursday Night: The backdoor front will be through the area Thursday, turning flow out of the northeast and bringing slightly cooler conditions with highs in the mid to upper 70s expected. PWAT's should remain above 0.75" through the day with increased cloud cover expected, but dry conditions should prevail as the upper ridge moves overhead with a shortwave approaching the Southern Plains. Overnight, mostly to partly cloudy skies will limit radiational cooling as lows keep toward the low to mid 50s.

Friday and Friday Night: On Friday the upper ridge will become increasingly suppressed as the shortwave now moves closer to the Mississippi Valley through the day. Low level flow will turn out of the southwest and moisture will increase to near 1.25" through the day with moderate warm advection aiding in bringing temperatures toward the upper 70s to lower 80s despite increased cloud cover. Afternoon highs could near record values where the record value at CAE is 81F and 82F at AGS. Continued moisture advection and the approaching shortwave could bring isolated rain showers late Friday night, but the better chances hold off until Saturday morning. Overnight lows should be mild with high low level moisture and mostly cloudy skies, in the upper 50s to low 60s.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Key message(s):

- Next system passes Saturday with isolated to scattered rain chances the first half of the day.

- Dry and warm conditions Sunday and Monday.

- Another system moves in by Tuesday with another chance for rain.

A flip-flop with deterministic guidance continues for the evolution of the shortwave expected to pass through the region on Saturday. The 12z GFS pulls the bulk of forcing from this north of the FA while the ECMWF, NAM, and Canadian have the southern periphery of it scraping the FA. The signal for strong 925-850mb moisture transport is apparent across model runs as PWAT's may rise further to just shy of 1.50" (above the NAEFS 90th percentile) Saturday morning ahead of a cold front. Overall, this is expected to lead to isolated to scattered shower chances the first half of Saturday where a couple storms can not be ruled out. Drier conditions are expected behind the front Saturday night as an upper ridge and surface high pressure fill back in. Temperatures are a bit tricky Saturday with blended guidance pushing the upper 70s to low 80s again, but increased cloud cover and rain chances that could linger into the afternoon may keep temperatures a bit lower.

The upper ridge behind Saturday's system should dominate Sunday and Monday with cooler temperatures (still just above normal) and dry conditions, though PWAT's should still be over 0.50" each day. A more potent shortwave is progged to eject out of the Southern Plains Tuesday and into Wednesday, which brings another potential for at least isolated rain chances each day. Spread amongst global models on the track of the shortwave is fairly large at the moment so confidence is not particularly high in greater than slight chance PoP's right now. Temperatures near normal are expected into the midweek at this time.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

VFR anticipate through much of the period, but fog is possible at AGS/DNL late.

Mainly clear skies are being observed at the time of this writing across the area. Expect a few clouds as we head through the afternoon. West southwest winds, gusting to around 15 kts are anticipated to continue through about 00z before diminishing to light and variable or calm at the terminals. Winds become north to northeasterly after around 14z and increase to about 5 kts. There remains potential for some fog at AGS/DNL, so have kept the BR group in the TAF for now.

EXTENDED AVIATION OUTLOOK...VFR conditions likely continue through most of the week with dry air in place. Increasing moisture Friday night will lead to chances for rain and possible restrictions.

CAE WATCHES/WARNINGS/ADVISORIES

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