Key MESSAGE 1, For the rest of today, a weakening shortwave will bring cloud cover to the area with a very small chance of precipitation before our focus turns to the next wave. On Wednesday, a low pressure system will move out of the mid-Mississippi Valley and push northward through the Ohio Valley, guided by a weak upper level trough. Short term models are showing much more meager rain chances and may keep eastern portions of the area dry till afternoon or later. In a similar theme, instability driving any potential convection looks to stay well below 500J/Kg until very late in the afternoon/early evening. While we remain in a Marginal Risk across the entire forecast area, western portions of the area could realize more of the instability during the afternoon hours with eastern areas more towards sunset.
Following in its footsteps, another shortwave will move off of the SC/GA coast on Thursday. Models show it somewhat disorganized and our forecast area on the northern fringe of any precipitation or convective activity. Pops generally reside in the slight chance to low chance regime which is lower than Wednesday.
KEY MESSAGE 2, Turning attention to the weekend, our next chance for significant rainfall to try and eat into the persisting drought over the area will be on Saturday as a low pressure develops off of the southeast coast and works its way over eastern NC. As this is happening an upper level low centered over Ontario and Quebec will work to deepen an upper level trough that will begin to push a supporting wave out of Texas which will eventually elongate into the frontal system that will accompany the coastal low. The merged systems will push through Saturday night into Sunday and move offshore but not before some significant rainfall with at least the southern half of the area having a 50% chance of at least an inch of rainfall.
As far as convection is concerned, currently most of the instability remains offshore but strong deep layer shear could help sustain any convection that initiates. Still a lot of uncertainty in the models regarding how strong the low will get and will have to monitor as the system gets closer.
18z Tuesday through Sunday VFR conditions will hold for the remainder of the afternoon and early tonight. Thereafter, patchy fog may develop across interior ENC as the low levels become saturated overnight with light to calm winds. Occasional mid and high based cloud cover will likely limit the fog from becoming dense, and generally 4-5 miles MVFR level fog is expected at this time overnight into early tomorrow morning. Vfr conditions return soon after sunrise, but ceilings will be lowering through the morning as rain showers approach from the west in advance of a frontal system. Mvfr ceilings will likely develop early to mid afternoon as rain and thunderstorm chances increase.
Outlook: MVFR conditions will continue tomorrow night until showers and thunderstorms exit off the coast, and then VFR is expected through the rest of the work week. Winds generally in the 5-15 kt range through the period. Another low pressure system may bring widespread rain for the weekend and a return to sub VFR conditions.
Based on latest guidance, have extended the Small Craft Advisory for the northern waters to 9z Wednesday for seas of 6 feet. This is mainly for outer portions of the 20 nm zone as areas closer to shore should remain under the 6ft threshold.
Current observations showing easterly winds around 15 kt or less with seas around 3-5 ft in most areas. Winds will become variable today as high pressure transits the area, becoming southerly late tonight but should remain less than 15 kt.
Outlook: A low pressure system is progged to pass north of the area Wednesday night and could see low end SCA conditions over the nearshore coastal waters S of Oregon Inlet redevelop late Wednesday afternoon night into Thursday. Another low pressure system may pass across or just south of the waters late in the week which could bring another chance for small craft advisory criteria to be met.
Nc, beach hazards statement until 8 pm EDT this evening for ncz203- 205. Marine, small craft advisory until 6 am EDT Wednesday for amz150. Small craft advisory until 8 am EDT Wednesday for amz152-154.
