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 /00Z MONDAY THROUGH FRIDAY/

The front that has been stalled across the eastern Carolinas for the past couple of days is retreating back to the north. The very humid airmass behind the front has a high probability to yield IFR stratus inland tonight. Residual low stratus at KFLO at this time of this writing (24/2330z) is expected to dissipate around 25/0000z, but should redevelop after 03z. This same stratus bank should spread north to encompass KLBT around 05z. Along the coast there is lesser likelihood of low stratus, however marine cumulus with low cloud bases in the 1500-2500 foot range will march onshore producing periods of SCT to BKN MVFR ceilings mainly this evening.

Coastal showers could get an early start on Monday, developing in a scattered fashion over KILM, KCRE, and KMYR by 13z. Inland low stratus may take a good portion of the morning to lift, but renewed deep convection should result afterward with clusters of showers and thunderstorms developing by 17z and lasting through the afternoon hours.

Extended Forecast...There is a moderate to high potential for late night and early morning low stratus or fog at KFLO and KLBT each day this week. In addition, there is a moderate to high potential for afternoon showers and thunderstorms Tuesday and Wednesday. Convective activity may reduce in coverage somewhat Wednesday and Thursday and shift preferentially toward the coastal airports KILM, KCRE, and KMYR.

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.