textproduct: NWS Wilmington

WHAT HAS CHANGED

No significant changes from the previous forecast with this update.

KEY MESSAGES

1) Deep tropical moisture will maintain a low potential for excessive rainfall through Thursday.

DISCUSSION

KEY MESSAGE 1... Deep tropical moisture will maintain a low potential for excessive rainfall through Thursday.

Isolated to scattered showers and storms still expected this aftn and evening in association with the sea breeze and interaction of convective outflows. Severe weather is not anticipated, but there is a low risk of minor flooding if storms train over the same area.

For much of Thu the air mass remains unchanged with an abundance of deep moisture, although precipitable water is down a bit compared to earlier in the week. Initially forcing is weak with limited low-level convergence and pockets of surface-based instability under flow aloft that is weakly divergent bordering on being convergent. The lackluster environment will keep storm coverage limited into Thu afternoon, likely scattered sea breeze action, until a cold front moves in from the north. The front has the potential to kick off more widespread showers and thunderstorms given the environment it is moving into. Exact timing of the front is still in question, but nearly all of the guidance insists the front will push south of the area sometime Thu night into Fri. Heavy rain will be possible in any convection that develops along the front with potential for significant rainfall amounts. However, flooding is not a concern at the moment.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Mostly VFR through the 18Z TAF period. Convection has just started to fire up over the last hour or so over parts of northeast SC and the NC coastal plain. Threw in TEMPO groups at KILM, KCRE, and KMYR to represent TSRA affecting the terminals in and out prior to 00Z Thursday. Confidence is slightly less over KFLO and KLBT, so PROB30 groups felt a bit more appropriate there. Convection should wane by sunset, leading to a lull through the overnight hours. Winds will slowly veer to the west by the time sunrise comes around Thursday morning, as a frontal system begins to approach from the north. Some low ceilings may try to form inland, especially over KFLO and KLBT, but confidence is a bit too low to put into the TAF at this time. VFR ceilings start to build again towards the end of the period, but the convection should mostly hold off until after 18Z.

Extended Forecast... The threat for late-night low stratus or fog will continue through much of this week at KFLO and KLBT. An approaching cold front Thursday will bring more widespread showers and storms Thursday afternoon and evening. After a brief lull on Friday, the front retreats back towards the area, potentially creating more flight restrictions over the weekend.

MARINE

Through Thursday... Moderate to fresh breeze out of the southwest continues through this evening. Pressure gradient tightens slightly tonight, which may allow gusts to escalate over 25 kts at times during the overnight hours for the coastal waters from Surf City, NC to Cape Fear, NC out 20 nm. However, it does not appear consistent enough to issue a Small Craft Advisory at this time. Winds may gust up to 30 kts at times over the offshore waters out 60 nm from Surf City. This gradient finally relaxes late Thursday morning, and winds shift slightly to the WSW. Seas at 2-4 ft along the coastal waters out 20 nm, which may bump up to 3-5 ft during the gradient increase tonight. Seas at 4-5 ft over the offshore waters out 60 nm, with a bump up to 4-6 ft during the gradient increase. Outside of wind waves, look for a primary southeasterly swell at 8-9 seconds.

Thursday night through Sunday... A cold front will push south across the waters Thu night into Fri with winds veering from southwest to northeast. Northerly surge Thu night into Fri will briefly increase winds and seas, but conditions will remain below SCA thresholds. The front stalls in the area Fri, likely just to the south, before returning back north Sat. The result will be variable winds with speeds around 10 kt as the pressure gradient remains weak. A second front pushes south Sat night into Sun, setting up another northerly surge for Sun with winds up to 15-20 kt.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ106- 108. SC...Beach Hazards Statement until 8 PM EDT this evening for SCZ054- 056. MARINE...None.