textproduct: NWS Wilmington

WHAT HAS CHANGED

Aviation discussion updated for 12Z TAFs.

KEY MESSAGES

1) Widespread showers and a few thunderstorms are expected today and tonight ahead of an approaching cold front.

DISCUSSION

KEY MESSAGE 1... Widespread showers and a few thunderstorms are expected today and tonight ahead of an approaching cold front.

Showers are currently impacting the coast and I-95 corridor by separate mechanisms. Onshore flow at the coast is providing deep theta-e advection with low level convergence at the coastline producing scattered tropical-like showers. Rain rates could support some localized heavy rainfall in our coastal communities early this morning. Inland showers are starting to decrease in intensity as the existing instability is undercut by a slow-moving cold front. Isentropic lift in this area is weak. The higher theta-e air mass to the south could interact with this region through the early morning hours and spawn additional showers between the two areas of focus, but with the surface front stalled (and pivoting westward) the heavier rain should stay to the east of I-95.

Ongoing theta-e advection should sustain shower activity in some fashion along the coast this morning. Weak energy aloft will skirt the coast by late morning and the low level warm air advection just off the coast could support a few weak thunderstorms. Efficient tropical showers will be the main concern here with a low chance of severe weather. Heavy rain over several hours this morning with increasing thunderstorm chances this afternoon could lead to isolated flooding concerns in one or two of our more urbanized coastal communities. This threat will continue until late afternoon with the loss of daytime heating and weak subsidence following the upper level impulse.

The slow-moving front will begin a southeastward crawl following the upper level impulse this evening. The moist air mass to the east and eventual forward progression of the front should increase the intensity of isentropic lift. A steady rain is expected to develop east of I-95 from the southwest. This area of rain will continue overnight, but confidence is lower regarding an end time. Dry air aloft will be rapidly surging southward during this time which will cut the depth and intensity of rain-prodcuing clouds. The latest forecast maintains rain through mid-morning Monday which is a slightly earlier end time compared to previous forecasts.

AVIATION /10Z SUNDAY THROUGH THURSDAY/

Unsettled weather continues across the area with a slow-moving front across the northern part of the area. Solid IFR conditions inland will persist into the afternoon before rising to sub 2k ft ceiling MVFR. Along the coast a mix of MVFR/VFR with occasional IFR (within any showers/storms that develop) will continue for much of the day. A few thunderstorms will be possible today at the coast as onshore flow supports weak instability and periods of heavy rain. Front moves back and forth across the area today, resulting in low confidence in timing of convection and deteriorating conditions for coastal terminals.

The front moves across the area and offshore tonight, accompanied by a final round of rain this evening and into early Monday morning. This precipitation should be more stratiform with northerly winds at a steady pace and LIFR for much of the area.

Extended Outlook... IFR conditions linger into Monday with VFR returning late Monday. VFR dominates thereafter through Thursday.

MARINE

Light southerly flow continues through Sunday with a slow- moving cold front remaining inland. The front will begin to move offshore tonight with northerly, then northeast, flow developing behind the front. The surge of stronger winds holds off until a reinforcing trough reaches the waters on Monday night or early Tuesday. Still expect to see headline conditions develop once the surge arrives. Anticipate conditions to persist into Wednesday.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...None.