textproduct: NWS Wilmington

WHAT HAS CHANGED

Updated 00Z TAF discussion below. A lull in the rain may build in inland for the next several hours before another round along the back of the low as it pushes offshore. Showers along the coast coming onshore will make for heavier and more sporadic rainfall.

KEY MESSAGES

1) Light to moderate rainfall will bring minor drought relief this evening into tonight.

2) Temperatures may approach record highs Friday.

DISCUSSION

KEY MESSAGE 1: Light to moderate rainfall will bring minor drought relief this evening into tonight.

Moisture is about to surge quickly into the area as southwesterly flow develops just ahead of an approaching low and frontal boundary. Increased isentropic upglide in the very near term will then benefit from deeper ascent this evening associated with DPVA and height falls from the mid level low currently spinning across MS. Rain will increase in coverage and intensity through evening and then start diminishing quickly from the west by about 06Z as the multi-centered low pushes the boundary into the area, the front itself possibly even offshore by 09Z according to some of the faster solutions. Thunder has been and continues to be a tough call. HREF means keep instability generally offshore but a few of its ensemble members to have a few hundred joules/Kg over land so have left in the forecast. Outside of any mesoscale variation by said convection the area stands to see 0.5"- 0.75" of rainfall. Sea fog could also develop and effect the immediate coast esp coastal Brunswick County in the SW flow. It will be pushed out to sea and no longer plague the coast or adjacent waters with the wind shift.

KEY MESSAGE 2: Temperatures may approach record highs Friday.

An airmass warmed by strengthening sunshine over eastern Mexico on Wednesday will move northeastward across the Gulf Coast on Thursday and should reach the eastern Carolinas Friday afternoon. Forecast 850 mb temps near +13C are about one degree above the 90th percentile climatological value at KCHS and not too far from the daily max values observed this time of year. Even with partly cloudy skies there may be enough sun to boost Friday's highs to near 80 degrees inland.

Friday's current record high at Lumberton is 80 degrees from 2018, Wilmington is 81 from 1991, and at Florence is 83 from 2014. Besides cloud cover, another wildcard to consider is wind direction which could advect relatively chilly air onshore from where nearshore water temperatures are still in the 40s. Current models suggest winds turning south-southwesterly along the coast during the day Friday which should keep coastal cities, particularly Southport and the Myrtle Beach/Grand Strand area, significantly cooler than locations 15-20 miles inland.

AVIATION /00Z MONDAY THROUGH FRIDAY/

Ongoing heavy showers are periodically impacting coastal terminals with lighter stratiform rain inland. KFLO/KLBT may see rainfall stop for the next 2-3 hrs before another wave comes in from the west with some wind gusts ~20 kts. Have added some LLWS to coastal TAFs as stronger winds aloft clash with the lighter winds at the surface early tonight. Across the board, VSBYs should be largely MVFR with heavier rainfall dipping them into IFR and possibly lower territory briefly. CIGs right now are spotty with the transition from MVFR to IFR, but once IFR is established these should stick around until at least 12Z, any VSBYs should clear up with the low passage so ~6-7Z. SE winds will quickly become N/NW around midnight with the passage of the low, gusting ~20 kts in the morning before calming into the evening.

Extended Forecast...VFR during the day through mid-week, with a chance of fog/stratus each night and early morning. Increasing rain chances late-week could lead to more predominant restrictions.

MARINE

Through Monday...Winds to turn to SW and increase early in the period as frontal boundary approaches. Wind speeds will remain sub- advisory but seas will not, reaching criteria early this evening. Sea fog may develop but confidence is lower, most guidance suggesting about 2 SM restrictions. Later tonight the frontal veer to N winds expected. These winds will become gusty so expect advisory-worthy seas to be slow to abate; the current end times not changed with forecast cycle. Wave faces will be steepened by the wind shift. Some NE backswell may start to develop late in the period.

Monday night through Thursday night...Light northeast winds are expected Monday night as high pressure settles across North Carolina and Virginia. The high will move directly over the coastal waters Tuesday afternoon, then offshore Tuesday night. Increasing south to southwest winds are expected Wednesday as the gradient tightens up between the departing high and low pressure moving across the Great Lakes. Cold nearshore water temperatures should create a very stable low level atmosphere, keeping marine winds from increasing as much as one might think given the strength of the weather systems. We're forecasting winds over the water to reach no higher than 15-20 knots with seas building to 4-5 feet Wednesday night, both just below Small Craft Advisory thresholds.

Even after the Great Lakes low weakens Thursday, moderate southwest winds should continue through Thursday night ahead of a cold front slipping southward across the Mid Atlantic states.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory until 7 PM EST Monday for AMZ250-252. Small Craft Advisory until 1 PM EST Monday for AMZ254-256.