Key MESSAGE 1, A notable late-season cold air damming setup continues across the piedmont with the wedge front remaining stalled from approximately the front stretched from Kenansville to Edenton. Low stratus has developed overnight to the west of the front overnight but so far visibilities have remaining aoa 2 miles, but cannot rule out patchy dense fog developing toward daybreak and continuing into the mid-morning hours before dissipating with the front progged to lift fully north of the area by Sunday afternoon.
KEY MESSAGE 2, Upper level ridging over the Eastern U.S. And troughing across the Central U.S. Will keep a southwesterly flow regime anchored across the Southeast over the next several days. The airmass within this regime will be characterized by a deep layer of moisture with PWATs consistently at, or above, 1.75", and moderate instability (500-1500j/kg MLCAPE). Meanwhile, each day looks to feature various sources of low- level and upper level forcing, with day-to-day variations that are not always modeled well. The theme here is that each day will likely carry a higher-than-climo risk of convection, but no one day looks like a complete washout. There are a couple of important items worth noting over the next few days, each highlighted below.
1) Severe thunderstorm potential. Deep layer shear will be weak through this weekend, but is forecast to improve some next week as we get a subtle glancing influence of stronger mid-upper level westerly flow. This may especially be the case Monday- Thursday, and machine learning and analog guidance continue to show a marginal severe thunderstorm signal. Additionally, an MCV lifting out of Georgia is forecast to support an enhancement to the LLJ today, and in tandem with the various surface boundaries in place, may provide just enough low-level turning for a brief landspout/tornado potential. This risk may be the highest during the day when CAPE is maximized along the seabreeze or any other surface boundary.
2) Heavy rain potential. An increasingly moist airmass combined with periods of moderate instability and increased convergence and low- mid level forcing should support very heavy rainfall rates at times. There may be just enough flow to prevent training or slower-moving convection, but at least some minor hydro impacts may develop where rainfall rates are maximized, especially for urban/poor drainage areas. Of note, some guidance suggests rainfall amounts of 3"+ may occur where the deepest convection materializes.
07z Sunday through Thursday A wedge front remains stalled across western rtes early this morning, approximately a line from Edenton to Wallace. Low stratus and patchy fog has developed west of this line early this morning bringing IFR/LIFR conditions. To the east, conditions are MVFR conditions are prevalent, occasionally lifting to VFR. The front is progged to lift north of the area by late morning with conditions improving to MVFR mid to late morning with pred VFR returning this afternoon. Scattered showers and thunderstorms becoming a concern again today esp as the day goes on a sfc heating builds, but confidence is low to moderate regarding the location and timing of these heavier showers and storms. Continue to handle TSRA threat with a prob30 fcst.
Outlook (Monday through Thursday): An unsettled weather pattern will continue into mid week with multiple opportunities for sub- VFR conditions in SHRA and TSRA. A nightly risk of low CIGs and VIS appears plausible as well. Drier conditions look to arrive by Thursday.
A warm front currently draped across the Albemarle Sound will lift north of the area this morning. Light easterly winds will become southerly once the front fully lifts north of the area. Some patchy marine fog will be possible at times across the Albemarle Sound until the front lifts north as well. There will also be a continued risk of thunderstorms through today, which may bring periods of higher winds and seas.
Meanwhile, a persistent and longer fetch of northeasterly flow north of the front has led to building northeasterly swell, with seas of 4-6ft currently being measured off the OBX. This increased swell of 9-10s is expected to linger through today, then gradually start to lay down on tonight. A Small Craft Advisory remains in effect for the nearshore coastal waters through this evening/night to account for this.
Outlook: A more typical summertime pattern is expected to close out the Memorial Day weekend, continuing into at least the middle of next week. Within this regime, there should be a daily building of winds and seas for the nearshore coastal waters and the inland rivers and sounds thanks to a strengthening thermal gradient. Occasional 25kt winds are expected during those times. There will also continue to be an increased risk of thunderstorms, but no all-day washouts are expected.
Nc, beach hazards statement from 8 am EDT this morning through this evening for ncz196-203>205. Marine, small craft advisory from 7 am this morning to 5 pm EDT this afternoon for amz150. Small craft advisory until 6 am EDT Monday for amz152-154.
