Marine Weather and Tide Forecast for Red Hill, SC

UPDATE
As of 720 PM...No major changes were made to the forecast.
Water vapor imagery early this evening shows the mid-level high in place across FL with multiple areas of lift moving by well north of the forecast area in the westerly flow aloft. Very limited chances for rain here tonight given convective inhibition. Will continue to see plenty of high clouds and with SWly surface winds lows tonight will be well above normal.



NEAR TERM /THROUGH SATURDAY/
Key Messages/Highlights: *Above normal temps w/ record high temps possible Saturday *Isolated damaging wind gusts/large hail possible Saturday aftn/eve

Confidence: *Moderate to High

Details: The mid-level ridge over the area will flatten as shortwave energy moves through ahead of a surface cold front.
Rain chances overall look to remain limited given the overall limited moisture but an isolated shower/storm is possible this evening, mainly in NC, and again Saturday across all of SE NC and NE SC. There looks to be quite a bit of instability/shear for any storms to tap into so can't rule out a few damaging wind gusts and/or some large hail. Temps should be the big story though as they will be well above normal, only falling into the mid 70s tonight for most locales, and then likely into the lower 90s away from the beaches Saturday when record highs could be reached (see Climate section below for details on the record temps).

SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/
A cold front is expected to settle southeastward through the are over Saturday night as a closed mid-upper low and its associated surface low track across New England. This far south, forcing for ascent will be meager, but surface convergence along the front may be enough to develop isolated strong convection. Prior to midnight, environmental parameters will support severe weather for any storm which manages to develop and grow tall enough to take advantage of 45-55 kts of effective shear amidst waning instability during the evening and early overnight. The Storm Prediction Center has maintained a Marginal risk (threat level 1 out of 5) for severe hail and wind as the anticipated coverage is very low. Otherwise, expect fairly rapid cooling during the evening after another hot day with west- southwesterly winds veering to westerly by the end of the night behind the cold front. Morning lows on Sunday should end up in the upper 60s to low 70s, coolest north, as somewhat drier air nudges in.

On Sunday, the front should stall just south of the area as it becomes aligned parallel to the flow aloft. Building ridging west of the forecast area will reinstate northwesterly flow aloft which could bring a cluster of showers or storms to far southern portions of the forecast area nearest to the front, but PoPs remain no higher than slight chance (20%) to account for this threat. Otherwise, mid-level dry air and subsidence should keep the region dry and very warm with highs in the upper 80s to around 90F with passing high cloudiness.

The continued increase in ridging west of the forecast area will result in greater subsidence developing through the atmospheric column, allowing for a drier and more capped atmosphere to develop on Sunday night. Thus, outside of a decaying shower scraping our southern areas, the region should stay dry overnight with lows in the mid-upper 60s.

LONG TERM /MONDAY THROUGH FRIDAY/
Confidence in the long-term forecast is rather low as a substantial western US trough with multiple vort maxes evolves and tracks eastward. This will drag the stalled front back northeastward as a warm front during the first half of the week, along which we may see a round or two of convection tracking southeastward into the forecast area. Otherwise, guidance generally agrees that higher rain chances can be expected around midweek as low pressure drags another cold front towards and through the area from the west. Atmospheric parameters become more supportive of severe thunderstorms on Tuesday and Wednesday, but the outcome of whether severe storms actually develop will depend on finer-scale details related to the mid- upper pattern. Furthermore, whether the cold front clears the area with dry weather in its wake will also depend on the outcome of this pattern, but overall, it appears a solid push of cooler and drier air will be in store at some point by the end of the week. However, until the front arrives, continued very warm weather is expected with highs in the upper 80s to around 90, although lower dew points away from the coast should allow low temps to fall to or below 70F in many locations on Monday night and Tuesday night, and potentially much cooler than that behind the front late in the week.

AVIATION /23Z FRIDAY THROUGH WEDNESDAY/
High confidence in VFR conditions through 00Z Sun, especially given limited convective chances. Also, LLWS is expected late tonight, primarily for the coastal terminals as a west- southwesterly low-level jet increases across the area. Also, expecting frequent gusts of 20-25 kt with the heating of the day tomorrow.

Extended Outlook...Mainly VFR conditions are expected through the period.

MARINE
Through Saturday...
Moderate to high confidence this period. The area will remain between an inland trough and approaching weak cold front and offshore high pressure. Thus, southerly winds will prevail. The combination of the low-level jet and pressure gradient could push winds to near Small Craft Advisory levels Saturday when gusts to near 25 kt are likely, although we don't feel an Advisory is warranted at this time, especially since seas should stay 4 ft or less.

Saturday night through Wednesday...
Southwesterly winds on Saturday evening of 15-20 kts veer to westerly and subside as a cold front slides through the waters.
Winds become light and variable around or below 10 kts for Sunday and Monday as the front stalls just south of the area and wavers (although the sea breeze circulation should yield enhanced nearshore winds around 10-15 kts). The front should lift back northward at some point on Tuesday with winds becoming southerly behind it. Strengthening low pressure northwest of the waters will tighten the pressure gradient and lead to increasing flow on Wednesday ahead of a cold front, with chances for showers and thunderstorms peaking ahead of this front.

Seas will relax from their 3-4 ft state Saturday evening into the 2-3 ft range on Sunday as winds ease up behind the front.
Seas are expected to hold in the 1-3 ft range for Monday and Tuesday as the flow remains generally light. Seas increase in tandem with the increasing winds on Wednesday, although how high waves reach will depend on the strength of the low pressure system northwest of the waters. Outside of diurnally-driven wind waves, a persistent 1-2 ft southeasterly swell with a period around 9 sec will continue.

CLIMATE
A new record high was set at Florence, SC today (95F, the old record was 93F set in 2022). High temperature records may be challenged again Saturday as anomalously warm air overspreads the region ahead of a cold front. Record highs for our four climate sites are as follows:

Saturday, May 17th...
Wilmington, NC: 92F (1960, 1990)
Lumberton, NC: 96F (1941)
Florence, SC: 93F (1977)
N. Myrtle Beach, SC: 92F (1941)

ILM WATCHES/WARNINGS/ADVISORIES
NC...None.
SC...None.
MARINE...None.