textproduct: Columbia

SYNOPSIS

The slow warming pattern will continue for the rest of today ahead of a strengthening front to the west. Widespread showers are expected Thursday as this front moves through, along with some gusty winds into Friday. Drier weather and a steady warming pattern is then expected into the weekend and the middle of next week.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Clouds continue to increase with rain chances starting early Thursday morning.

A sharp shortwave trough can be seen entering the lower Mississippi River basin, turning upper flow increasingly out of the southwest over the Southeast with cirrus overspreading the region. Southwesterly flow should aid in bringing near seasonable temperatures in the upper 50s to lower 60s this afternoon before moisture begins to ramp up overnight as the shortwave approaches (PWAT's raise from 0.40" to over 1" by daybreak). Mostly dry weather is expected overnight but a couple hours before daybreak Thursday a warm advection regime sets up and fairly robust 290-300K isentropic lift develops as a bit more on a onshore component is seen in low level flow. This should bring isolated to scattered rain chances mainly in the southeastern Midlands that spread northward into Thursday morning. Due to cloud cover overnight, lows should be fairly mild, in the low to mid 40s.

SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/

Key message(s):

- Widespread showers expected Thursday ahead of a strong surface front.

The mid-level pattern across the eastern US will continue to amplify on Thursday as a deep trough digs east and downstream ridging increases. A leading shortwave will advect northeastward out of the gulf by early Thursday along with a surge of strengthening moisture advection. This will quickly enhance isentropic lift over the area as PWAT's jump to around 1.25" and rain chances become likely from roughly 6am onward; HREF members are in good agreement with a slug of moderate rain moving northward throughout the morning as this shortwave quickly lifts north and surface dews points climb into the 50's. HREF members are also consistent in showing a weak drier layer that will advect north for late morning, so we could see a brief reduction in rain chances before becoming widespread in the afternoon again. Diabatic cooling and a lack of strong near surface southerly flow will allow for some in-situ wedging to develop especially across the western Midlands and Upstate, so temps will run a bit cooler than guidance before southerly advection strengthens in the afternoon. Rain chances will continue into the evening before the surface front arrives, but by that point, moisture and forcing will be limited. The pressure gradient will however quickly strengthen behind the surface front and gusty winds over 30 mph are likely into Friday morning.

LONG TERM /FRIDAY THROUGH TUESDAY/

Key Message(s):

- Cool and dry conditions expected Friday and Saturday, followed by a modest warm up into next week.

Cold advection will dominate on Friday behind the front but some downsloping will offset and limit daytime high temps. So we will still climb to around average despite the front. Winds will remain gusty into the afternoon thanks to some notable mixing, with gusts over 30 mph likely. Beyond Friday, the pattern looks remarkably unremarkable. The pattern aloft will flatten out before deep ridging builds well to our west and we will sit under a fairly benign airmass. NAEFS and EC EFI highlight the lack of anything anomalous expected into the middle of next week.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Low clouds and showers may move in Thursday morning, bringing potential restrictions through the end of the TAF period.

The area sees increasing cirrus the remainder of the day with light southwesterly winds that become light and variable overnight. Tonight, moisture really ramps up and thus the potential for strato-cu and rain showers moves in after 09z. The highest confidence in possible MVFR ceilings prior to 12z is at AGS/DNL/OGB as model guidance indicates these ceilings should develop across the Coastal Plain before spreading northward through the morning. Showers are also expected to start overspreading the area after 09z, primarily in the form of a band through OGB and possibly toward the Columbia terminals. Continuing through the morning, there is indication ceilings may continue to lower some (though remaining MVFR) but greater chances for rain moves into all terminals as light southeasterly winds develop. There is some hint that high end IFR ceilings could develop toward the end of the period but confidence in this is not very high at the moment except near the Augusta terminals.

EXTENDED AVIATION OUTLOOK...Widespread rain and restrictions likely continue into Thursday night before drier air moves in on Friday, slowly bringing an end to restrictions. Drier air looks to remain in place for the weekend with lower chances for restrictions.

CAE WATCHES/WARNINGS/ADVISORIES

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