Marine Weather and Tide Forecast for Lake Murray of Richland, SC

KEY MESSAGES
- 1. Increasing moisture this weekend leading to chances for rain through Monday when a cold front moves through.

DISCUSSION
Key Message 1: Increasing moisture this weekend leading to chances for rain through Monday night when a cold front moves through.

Broad troughing along with an active southern stream jet will bring elevated rain chances over the next few days as a series of shortwaves interact with persistent gulf moisture. The first of these will move through Saturday, with rain chances mainly along and south of I-20. A decaying MCS complicates the forecast a bit and could cut off and rob some moisture as it propagates to the south of our area, like HRRR depicts. But regardless, high PWAT's and broad synoptic forcing along with weak instability should product some scattered-widespread showers, especially along and south of I-20 with relatively light QPF overall to the north, generally less than 0.5". This broad forcing will linger again on Sunday but with less instability in play, so while additional showers are likely, coverage and QPF totals will be light. More consolidated and heavier rain arrives late Sunday and Monday with stronger front and associated 500-250mb trough crossing the area. PWAT's push towards 1.75 - 2.0" across much of the ensemble guidance along with IVT above the 90th percentile. While we could have some convective MCS's that cut off some this moisture, the synoptic forcing, residual instability, and high PWAT's will allow for widespread showers- storms regardless. Instability does look lacking for any notable severe threat but skinny CAPE profiles paired with relatively high PWAT's present a heavy rain threat. Total rainfall through Tuesday morning is progged around 1-2" along and south of I-20 and 0.5-1.0" northward; 90th percentile in the LREF pushes towards 3.0" south of I-20 given the potential for efficient, convective rainfall both Saturday and Monday. Drier conditions arrive Tuesday has we eventually end up within the northwest flow regime of the persistent troughing.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
VFR conditions continue through early tonight, then potential MVFR ceilings to develop towards sunrise Saturday morning.

Upper level cirrus continues to overspread the region this evening ahead of an approaching shortwave trough, resulting in widespread BKN/OVC skies across all terminals. Guidance continues to show increasing low-level moisture overnight, with the potential for a few light showers or drizzle spreading from southwest to northeast late tonight into Saturday morning.
However, confidence is too low for a mention in the TAFs at this time, though a VCSH was included around the 10-11Z period.
Ceilings are expected to steadily deteriorate overnight, with MVFR cigs likely developing at most terminals around or shortly after 11Z. A few widely scattered showers may also develop midday Saturday.

Winds will gradually veer to the southeast around 5 knots this evening before becoming light and variable overnight. A more southerly to southwesterly flow is expected to develop during the day. Clouds should gradually lift Saturday evening, though BKN to OVC conditions are expected to persist into the night.

EXTENDED AVIATION OUTLOOK...Another system brings a chance for restrictions once again with showers and thunderstorms this weekend into Monday.

CAE WATCHES/WARNINGS/ADVISORIES
SC...None.
GA...None.