textproduct: NWS Wilmington

WHAT HAS CHANGED

Updated 12Z aviation section.

KEY MESSAGES

1) Good chances for rain will develop again Monday as low pressure moves offshore.

2) Canadian air spreading southward could bring temperatures 10 to 15 degrees below normal Tuesday and Wednesday.

3) A high risk of rip currents is expected at New Hanover and Georgetown county beaches today.

DISCUSSION

KEY MESSAGE 1: Good chances for rain will develop again Monday as low pressure moves offshore.

The backdoor cold front that blew through the area Saturday evening into early this morning should stall out later today across Georgia. Easterly winds within the cool airmass extend vertically up through 5000-6000 feet with west to northwesterly flow noted aloft.

A weak bubble of high pressure moving from the Great Lakes this morning to the Mid Atlantic coast this afternoon should begin to veer our low level winds more southeasterly with time. A shortwave trough crossing the Ozarks this morning will get close enough to the area tonight to develop surface low pressure along the stalled front in Georgia. Increasing Atlantic low level moisture plus an ascending plume of Gulf moisture lifted northeastward and into the mid levels by the developing baroclinic low should lead to a winter-like shield of rain developing across the Southeast tonight and lasting into Monday.

Confidence is quite high that measurable rain will fall across our South Carolina counties. There may be a distinct edge to the precipitation across southeastern North Carolina through early Monday afternoon which may reduce rainfall totals here. As the surface low pushes offshore Monday afternoon and Monday night, models develop a separate area of showers along a new cold front pulled southward behind the departing low. Any areas that don't get rain from the first half of the event will probably see measurable amounts from this second wave.

Uncertainty increases on Tuesday about how much rain may linger. The 00z GFS is essentially dry across the area while the 00z Canadian and yesterday's 12z ECMWF maintain a wetter pattern. Questions surrounding an amplifying upper trough along the East Coast suggest keeping at least some rain chances in the forecast through Tuesday.

KEY MESSAGE 2: Canadian air spreading southward could bring temperatures 10 to 15 degrees below normal Tuesday and Wednesday.

An exceptionally amplified upper air pattern for early June should feature a strong ridge along the Mississippi Valley into the Great Lakes and a deep trough along the East Coast, perhaps leading to a cutoff upper low near the Outer Banks Wednesday and Thursday. While the system appears at this time that it will be located too far east for any wet weather to occur across our area, a deep flow of Canadian air should bring temperatures well below normal to the Carolinas.

Forecast 850 mb temp of +7C to +9C is cooler than the climatological 10th percentile at the MHX upper air site for early June. An airmass this cool and dry could allow Tuesday night's and Wednesday night's low temperatures to slip deep into the 50s all the way down to the beaches. Our forecast low of 54 in Wilmington Wednesday morning would be the coldest June temperature since 52 degrees was recorded here on 6/5/2023 and would match another 54 degree morning on 6/9/2017. No record lows appears to be threatened.

KEY MESSAGE 3: A high risk of rip currents is expected at New Hanover and Georgetown county beaches today.

A 4 to 5 foot 6 second psuedo-swell will lead to a high risk of rip currents at New Hanover and Georgetown county beaches today, especially during low tide. Elevated swells will likely maintain a moderate, possibly high, risk of rip currents at east-and southeast facing beaches through Wednesday.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

VFR today with only high level moisture/clouds present. NE winds will be turning to the E and then SE. Clouds lower/thicken from SW to NE this evening with MVFR/IFR by tonight. Showers and storms will also spread NE across the region tonight leading to occasional MVFR vsby restrictions with brief dips to IFR possible in any deeper storms though such restrictions will be short-lived and at most may require the intro of some TEMPO groupings.

Extended Forecast...There is a moderate to high potential for periodic MVFR/IFR conditions in showers and thunderstorms late Sunday night into the first half of Tuesday as a low pressure system and cold front impact the area. VFR conditions should develop Tuesday night through Thursday.

MARINE

The backdoor cold front moved across the coastal waters late Saturday evening with ENE winds 20-25 knots still ongoing now. Wind speeds are anticipated to decrease slowly through the morning hours as high pressure over the Great Lakes builds southeastward. The Small Craft Advisory will expire at 1pm today as seas begin to fall below 6 feet inside 20 miles of shore.

The front will stall across Georgia later today. Low pressure developing along the boundary tonight will move east and into the Atlantic on Monday. This winter-like pattern should lead to another wave of rain Monday into early Tuesday. While there won't be an immediate increase in wind as the low moves to our south Monday, the gradient between the low and a new area of high pressure building across the Great Lakes on Tuesday and Wednesday should lead to increasing northerly winds which have at least a moderate potential to reaching Small Craft Advisory thresholds. Objective model blends show about a 40 percent chance that wind gusts across the 20-60 mile offshore waters could reach the 34 knot gale threshold Tuesday into Tuesday night.

ILM WATCHES/WARNINGS/ADVISORIES

NC...High Risk for Rip Currents from 6 AM EDT this morning through this evening for NCZ108. SC...High Risk for Rip Currents from 6 AM EDT this morning through this evening for SCZ056. MARINE...Small Craft Advisory until 1 PM EDT this afternoon for AMZ250- 252-254-256.