textproduct: Newport/Morehead City

WHAT HAS CHANGED

Updated Aviation Discussion.

KEY MESSAGES

1) Above normal to near-record high temperatures and mostly dry conditions to continue through mid-week.

2) The next frontal system approaches the area late week, bringing the next appreciable chance of showers and thunderstorms

DISCUSSION

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).

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 Carolinas by Thursday or 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 risk of 0.50"- 1.00" 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.

AVIATION /00Z MONDAY THROUGH FRIDAY/

VFR conditions are noted with high pressure ridge centered offshore extending into the Mid-Atlantic this evening. Expecting primarily VFR conditions through the period with one notable caveat for early Mon morning.

Steady S'rly winds will gradually ease through tonight bringing our challenge for the evening; the potential for low stratus/ground fog. As of this update we may remain mixed enough and there may be enough of a dewpoint depression still to preclude any threat for ground fog/ low stratus Mon morning. However, guidance has been a mixed bag with some guidance showing winds decoupling and enough low level moisture remaining trapped beneath the nocturnal inversion to support patchy ground fog and/or a layer of sub-VFR stratus. If we do see ground fog it would likely spread from SW to NE starting at OAJ/EWN first between 07-09Z and then spreading to ISO/PGV and adjacent terminals between 09-11Z. Any ground fog that does develop would be non impactful to operations regardless. For now have kept in line with the previous TAFs and only noted 6SM vis and a FEW deck of IFR ceilings at all TAF sites between 08-13Z.

If ground fog does develop expect VFR conditions to quickly return by Mon morning and persist into Mon evening with only notable weather being the shift in winds associated with the daily seabreeze.

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.

MARINE

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. However, there will be an increased risk of thunderstorms along the front.

MHX WATCHES/WARNINGS/ADVISORIES

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