Key MESSAGE 1, Notably warm low-level thicknesses beneath anomalous mid-upper level ridging will continue to support above to well above normal temperatures across the Carolinas through the middle of the week. While well above normal temperatures are expected, temperatures look to stay just shy of records. It may be close across the coastal plain, though.
Additionally, despite increasing low-level moisture, ridging aloft should tend to suppress convective activity outside of perhaps a rogue shower or thunderstorm where convergence is maximized along the seabreeze (Albemarle Sound/NRN OBX vicinity). Still, probs of this occuring are low enough to keep out of the forecast with this update.
KEY MESSAGE 2, The mid-upper level ridge is forecast to break down some late-week and into the weekend. This should allow a front to drop south into the Thursday into Friday. There continues to be some uncertainty regarding whether or not the front fully makes it through ENC, whether it stalls, or whether it lifts quickly back north as a warm front. Given the strength of the ridge, it stands to reason that the front will struggle to get fully through ENC, and the forecast reflects this scenario. Then, ridging may try to make a comeback late in the weekend, which would favor the front lifting back north as a warm front by early next week.
Based on the above, increasing moisture and instability along the frontal zone should support an increased risk of showers and thunderstorms. Probabilistic guidance shows a solid chance of 0.25"- 0.75" each day from Thursday into the weekend. However, it should be noted that those amounts will be highly dependent on the evolution of the frontal zone. Initially when the front drops into the area, there may be just enough flow aloft to support some thunderstorm organization and perhaps a marginal risk of strong to severe thunderstorms. Machine learning and analog guidance support this potential as well. However, no one day stands out as having a higher risk of severe thunderstorms.
Notably high PWATs along the frontal zone should support higher rainfall rates in convection. However, notable hydro impacts are not expected due to the recent dry stretch and ongoing drought conditions.
06z Monday through Friday VFR conditions are noted with high pressure ridge centered offshore extending into the Mid-Atlantic this evening. Chances build for sub-VFR CIG/VIS through the early morning hours. Vfr expected after sunrise through the day, before a more likely round of sub-VFR conditions takes place Monday night/Tuesday morning.
Steady S'rly winds will gradually ease through the early morning bringing the potential for low stratus/ground fog. We still remain mixed with sustained winds around 5 kts observed through much of the area. As we approach sunrise, chances for brief decoupling increase a tad, and this would be our window for any spotty sub-VFR conditions to initiate. If we do see ground fog it would likely spread from SW to NE starting at Duplin/Onslow county first. Short period of favorable conditions will make it difficult for fog to develop further north and east. With the winds, low stratus is a slightly more likely outcome but still kept TAFs VFR through the morning. Will monitor observations and make amendments as needed once there is proof of sub-VFR conditions upstream.
Generally clear skies today, with a shift in winds from SW to S associated with the daily seabreeze, gusting to 15-20 knots behind it.
Tonight, chances for decoupling are higher, and solid low level moisture primes us for a fog/low stratus night.
Outlook: A dry seabreeze pattern looks to continue through Wednesday. Beyond then, a frontal boundary sagging south into ENC is expected to bring an increasing risk of SHRA, TSRA, and sub-VFR conditions.
A summer-like pattern continues through the middle of the week, with a daily building of winds to 10-20kt each afternoon and evening as the thermal gradient tightens. This will especially be the case for the inland rivers and sounds and the nearby coastal waters within 20nm of the coast. This should also support periods of 3-5ft seas.
Outlook: A frontal boundary is forecast to sag south into the area late-week, then meander around the area through the upcoming weekend. This leads to lower confidence regarding winds and seas, but especially wind direction. In general, the risk of 25kt+ winds appears low during this time ahead of the front, with slightly higher chances of seeing 25+kt gusts behind the front. There will be an increased risk of thunderstorms along the front.
Nc, none. Marine, none.
