Key MESSAGE 1, The frontal boundary is slowly pushing across southern portion of the FA this afternoon will move south of the area overnight. Scattered showers and thunderstorms have blossomed over the north and eastern portion of the area this afternoon. While SPC continues to have ENC in marginal risk of severe storms today with modest instability and shear present, DCAPE is much lower than yesterday, less than 700 J/Kg, and storms have remained relatively weak with strongest gusts only around 30 kt. While cannot rule out an isolated storm producing strong wind gusts, the over all severe threat appears minimal.
The storms have produced locally heavy rainfall to some areas, however. Highest rainfall totals so far today has been across western Hyde Co where 1-1.5" has fallen this afternoon. Anomalous moisture, moderate instability, and areas of enhanced convergence will continue across the Carolinas early this week. Guidance differ on where the most persistent convection will occur, but the pattern supports the potential for bands of training convection. If these bands do, indeed, develop, short- term hi-res guidance suggests a reasonable worst-case scenario is for rainfall totals of upwards of 3-5". Amounts aside, the anomalous moisture plus enhanced lift and moderate instability suggests rainfall rates of 1-3"/hr at times. All of this supports the potential for isolated to scattered instances of flash flooding. Still considering a Flood Watch for portions of the area, but there remains some uncertainty regarding the placement of the heaviest rainfall and where the greatest risk of training convection will be. Ensemble guidance show the strongest signal across coastal sections of the FA, but probabilities for greater than 3" over the next 48 hours are only around 20-40% for this area. Given the drought conditions, most of the area should be able to handle this amount but hydro concerns may be focused in urban areas where rainfall rates may overcome drainage systems for short bursts of time. Periods of moderate to heavy rain may linger into Monday, but instability is forecast to wane by then, and this may lead to lower rainfall rates compared to today.
KEY MESSAGE 2, Low pressure developing off the coast of NC on Monday is expected to keep a "cooler" northeasterly flow going across ENC through Tuesday. This should keep temps below normal for a couple of days, and consequently lower the heat risk. This looks to be short-lived, though, as a warming southwesterly flow regime returns mid to late-week. Guidance continue to show a strong signal for above normal temperatures and an increased heat risk once again.
00z Monday through Friday Moist and moderately unstable airmass, combined with lift associated with a stalled frontal boundary bisecting the Carolinas is currently supporting a widespread area of scattered showers and thunderstorms especially across the eastern part of NC. With the front moving little and waves of favorable mid- level disturbances, convective activity is likely to be ongoing through most of the overnight hours. Predominant conditions should be VFR for the next few hours but gradually fall to MVFR and then IFR pre-dawn. Any sites that see direct impacts from showers/storms will likely see further deterioration to IFR/LIFR for a brief period.
Predominantly MVFR returns by midday Monday. Higher instability will be confined mainly from EWN south, so VCSH is more likely to the north while risk of storms is more probable closer to the coast.
Outlook (Monday night through Thursday): Moisture and lift along a stalled front should continue to support periods of SHRA into Tuesday with periods of low CIGs (IFR/MVFR). A more predominant period of VFR conditions looks to return by the middle of next week.
A front is slowly pushing across the southern waters late this afternoon and will push south of the area overnight. An area of low pressure will develop along the front near Cape Fear and slowly slide eastward through Tuesday. While significant deepening of the low is not expected, the tightening gradient will lead to building easterly winds, especially for waters north of Ocracoke Inlet. South of there, winds are expected to lighter and more variable as the low moves slowly east away from Cape Fear. From Ocracoke Inlet north, easterly winds of 15- 20kt are expected with some guidance suggesting some gusts to around 25 kt possible at times, mainly across the central waters. Will see building seas with a decent easterly fetch off the coast with 3-5 ft seas across most of the nearshore waters, however guidance is bringing seas up to 4-7 ft across the outer waters and central nearshore waters. Have issued a SCA for the central waters from Oregon Inlet to Ocracoke Inlet Monday and Monday evening.
Outlook (Tuesday through Friday): Low pressure will slowly weaken and move east on Tuesday with high pressure building in mid to late week bringing improved boating conditions.
Nc, none. Marine, small craft advisory from 8 am Monday to midnight EDT Monday night for amz152-154.
