textproduct: NWS Wilmington

WHAT HAS CHANGED

Another Coastal Flood Advisory in effect tonight for the lower Cape Fear River, including downtown Wilmington, from 11 PM to 2 AM EDT.

Otherwise, no major changes coming down the track for this afternoon's forecast update. Aviation discussion updated below for the 18Z TAFs.

KEY MESSAGES

- 1) Another round of minor coastal flooding expected at this evening's high tide for the lower Cape Fear River, including downtown Wilmington.

- 2) Warming trend continues through Saturday, allowing temperatures to soar above seasonal norms. Next earnest rain chances return by the weekend.

DISCUSSION

KEY MESSAGE 1...Another round of minor coastal flooding expected at this evening's high tide for the lower Cape Fear River, including downtown Wilmington.

Positive tidal departures continue to improve, but high astronomical tides are still lingering, thanks to the full moon from three days ago. Wrightsville Beach got close to minor coastal flooding thresholds during this morning's high tide, but didn't quite get there. Myrtle Beach barely hit the thresholds for about 45 minutes or so. Thinking those areas will get close again during tonight's high tide, but should stay short, as the higher of the two high tides was this morning.

Minor coastal flooding appears to be more likely tonight along the lower Cape Fear River, including downtown Wilmington. Coastal Flood Advisory in effect from 11 PM - 2 AM EDT tonight.

KEY MESSAGE 2...Warming trend continues through Saturday, allowing temperatures to soar above seasonal norms. Next earnest rain chances return by the weekend.

Upper level heights and thicknesses have increased today, in part due to a ridge building in from the Gulf. As a result, temperatures have warmed up a fair amount today, with observations hovering in the low-to-mid 80s as of 2:30 PM EDT this afternoon.

Ridging will continue to build through Saturday, keeping the warming trend around. Temperatures warm up a degree or two everyday through Friday. Highs around 90F appear possible along and west of I-95 as early as Wednesday, with those chances solidifying more by Thursday and Friday (could potentially be 90-92F in some spots). Moisture parameters pick up as well, with dewpoints soaring into the 60s, and even into the lower 70s for the coastal areas Thursday through Saturday. Friday in particular could be the most hot and humid day of the week, with the heat index climbing up towards 93-95 in some spots (in October, mind you).

Pattern starts to flip by Saturday. The heat ridge starts to push offshore, while a very broad trough pattern that stretches from near the PNW all the way to New England helps to suppress the ridge southward. Weak shortwave energy breaks off the broad trough and will help produce scattered showers and perhaps a few rumbles of thunder Saturday, but nothing appears to be a washout at this time. These rain chances appear to get a bit more bullish by Sunday and into early next week, as part of the broad trough in the Ohio Valley amplifies and sweeps through the Southeast as a more organized frontal system. Still much to debate about the timing and organization of this system, along with what kind of rainfall amounts to expect.

What is becoming more apparent is a significant cooldown coming early next week, where highs may only get into the 70s. Bring back a more legitimate fall!

AVIATION /18Z TUESDAY THROUGH SUNDAY/

VFR continues through at least midnight. Light and variable winds this afternoon except east to southeast 5-10 kt along the coast once the sea breeze passes. Easterly flow post sea breeze will enhance low level moisture and a good bit of the guidance depicts MVFR/IFR fog development in the pre-dawn hours. However, the moisture is very shallow with dry air above it. The boundary layer moisture is around 75%, ideally would want to see AoA 90%. Bulk of the guidance has the 925mb moisture under 70%, again would like to see 90-95% in that layer. So what may end up happening is visibility drops to 2-4SM for brief periods of time then comes back into the 5-10SM range for an extended period before dropping again with the cycle repeating, much like CRE did last night. Not sure duration would even be long enough to warrant a tempo and it could be argued the depth of the fog will prevent it from being operationally significant even if the reported visibility is MVFR/IFR. Something subsequent TAFs will need to address. For now have added a 4/5SM group for all sites, but confidence remains low.

Extended Forecast...Potential for MVFR/IFR fog each morning through Saturday. Restrictions in both visibility and ceiling possible Sunday and Monday.

MARINE

Through Sunday...Rather benign marine conditions expected through the first half of the weekend, with a gentle breeze that fluctuates a bit out of the E to S during the daytime, becoming a more variable light breeze at night. Winds strengthen very slightly up to a moderate breeze out of the SSE by Sunday. Seas remain at 1-2 ft through Wednesday, with perhaps some 3 ft waves trying to sneak into the waters out 60 nm by Wednesday night. In between light wind chop, look for a persistent long period southeasterly swell at 10-14 seconds, and a secondary easterly swell at 8-10 seconds.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Coastal Flood Advisory from 11 PM this evening to 2 AM EDT Wednesday for NCZ107. SC...None. MARINE...None.