textproduct: NWS Wilmington

WHAT HAS CHANGED

All sections updated but no significant changes to the previous forecast.

KEY MESSAGES

1) A tropical air mass will lead to higher than normal rain chances/amounts much of the week, with excessive rainfall possible inland through Wednesday.

2) High rip current risk currently in effect for New Hanover and Pender county beaches.

DISCUSSION

KEY MESSAGE 1...A tropical air mass will lead to higher than normal rain chances/amounts much of the week, with excessive rainfall possible inland through Wednesday.

Confidence is pretty high that unseasonable amounts of tropical moisture from the Atlantic and Gulf will continue in place across northeast SC and southeast NC through much of the week. However, confidence in rain chances/amounts lowers mid to late week as the upper low to the west shifts farther from the area leading to less forcing overall. Most of the showers/storms thru Wed will follow the typical summertime pattern of being closer to the coast and offshore earlier in the day before transitioning inland later in the day as the sea breeze develops. On Thu the highest rain chances should shift closer to the coast as as an inland trough develops closer to the coast. On Friday the best rain chances should shift into SC ahead of a backdoor cool front with chances thereafter highly uncertain and dependent on the frontal position and upper pattern.

Rainfall amounts are always tricky in tropical/convective regimes but certainly several inches total are possible in any given spot through the week, with inland areas generally expected to see the most rainfall. Global ensemble probabilities generally indicate mean totals of ~2-3" across SE NC and NE SC (highest inland, especially near/west of I-95 in SC) with max totals of ~6-8". However, it's important to note that global models don't capture the finer details of convection well and thus are usually underdone regarding rainfall amounts. Thus, a few spots could easily pick up more than 8". Although these rain amounts won't be enough to completely end the drought across the entire area they should certainly help put a nice dent into it in some areas. The tropical nature of the precipitation will lead to heavy rain at times which could cause localized flash flooding, especially thru Wed across inland areas.

KEY MESSAGE 2...High rip current risk currently in effect for New Hanover and Pender county beaches.

A high risk of rip currents is in effect for today for New Hanover and Pender county beaches due to 3-4 ft SSE swell leading to strong rip currents, with holiday weekend crowds contributing to increased rescues by lifeguards. Moderate rip risk in effect for beaches south of Cape Fear. The high rip current risk may linger through Monday for beaches north of Cape Fear, and this will be evaluated further later today.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Low ceilings inland are finally lifting as the CAD wedge begins to break down. A line of showers and thunderstorms are currently just inland from the coast, and will continue shifting westward through this evening, with rain and TS chances increasing for areas near I- 95 in the next hour or so. Rain chances dwindle tonight, though there may be a few lingering showers. Low stratus is forecasted to develop by 6z, and linger into midday Monday, due to very moist low levels in southerly flow, with IFR possible along and west of I-95. While some patchy fog is possible, boundary layer winds should be elevated enough to hinder low vsbys. Winds remain out of the south throughout TAF period. Scattered showers and thunderstorms will redevelop Monday, first along the coast and then shifting inland.

Extended Forecast...Periodic MVFR/IFR ceilings and/or visibility reductions from shower and thunderstorm activity possible across the area each day through at least mid week, especially inland terminals. In addition, look for MVFR/IFR from low stratus and/or fog during the daily pre-dawn hours.

MARINE

Through Monday...Bermuda high pressure remains dominant feature, with southerly winds and seas dominating the local waters. South winds 10-15 kts through Monday, with gusts to 25 kts in the 20-60nm waters off from Surf City to Little River Inlet. Seas 3-4 ft out to 20nm, and 4-6 ft from 20-60nm, with SSE 7 sec swell the primary component and a 1-3 ft ENE swell mixed in. Scattered showers and thunderstorms forecasted over the waters tonight into early Monday.

Monday night through Friday night... Southerly winds will prevail through Thu as the area remains on the western edges of Bermuda high pressure. A fairly weak backdoor cold front could then move south through the waters Thu night into Fri bringing more easterly winds. Conditions outside of showers/storms look to stay below headline levels though through the period with seas mainly up to 4-6 ft, highest beyond 20 nm, and wind gusts up to 20-25 kt at times.

ILM WATCHES/WARNINGS/ADVISORIES

NC...High Risk for Rip Currents until 8 PM EDT this evening for NCZ106- 108. SC...None. MARINE...None.