textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 18Z forecast.

KEY MESSAGES

- 1. Scattered showers possible later tonight into early Sunday with more widespread rain chances Monday. Potential totals continue to trend down.

DISCUSSION

Key Message 1: Scattered showers possible later tonight into early Sunday with more widespread rain chances Monday. Potential totals continue to trend down.

Deep moisture remains to our south today with PWAT's only around 1.0" across the area. We remain on the western edge of a weak shortwave embedded within the broad trough across the eastern US. This is temporarily increasing mid-level convergence and therefore capping us out today. So showers and storms chances are low the rest of today. A couple of brief showers are possible, but unlikely, across extreme southern Burke and the southern CSRA.

More widespread showers and storms are expected Monday as a stronger shortwave and associated surface front push through, but the potential for notable accumulations has continued to trend down. While some scattered showers are still likely across much of the area, surface low pressure development just offshore as a shortwave rolls through will prevent most of the deep moisture from advecting very far northward, therefore keeping the relatively low PWAT's in place that we saw Sunday north of I-20. PWAT's will favorably increase south of I-20 along with mid- level lapse rates becoming marginally more favorable. So heavy rain and storm chances are generally focused in these areas but the chance for notably accumulations, even over 0.5" looks rather unlikely now. Drier air fills in late Monday and Tuesday with another front moving through on Wednesday.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

VFR conditions likely into Monday morning with rain chances increases towards the end of the TAF period.

VFR conditions likely across the area for the rest of Sunday with only some scattered cu and light southwest surface winds into the evening. Moisture pushes in overnight into Monday morning and some morning stratus-fog is possible again dependent on how fast mid-level cloud moves in. Right now included a line for this morning potential but confidence is somewhat low. Rain chances and associated restrictions will push in towards the end of the TAF period.

EXTENDED AVIATION OUTLOOK...Lingering showers and storm potential into Monday evening before conditions will improve Tuesday with mainly VFR expected. Another front with more scattered showers and thunderstorms will approach the terminals later Wednesday.

CAE WATCHES/WARNINGS/ADVISORIES

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