textproduct: Newport/Morehead City

WHAT HAS CHANGED

The aviation forecast has been updated.

KEY MESSAGES

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

2) A 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 an anomalous mid-upper level ridging will continue to support above to well above normal temperatures across the Carolinas through Wednesday. Guidance shows similar low-level thicknesses each afternoon yielding highs generally in the lower 90s across the coastal plain but some warmer spots may reach mid 90s, remaining just shy of records. It will be closest across the coastal plain, however.

Additionally, despite increasing low-level moisture, ridging aloft should provide sufficient subsidence to suppress convective activity outside of perhaps a rogue shower or thunderstorm where convergence is maximized along the seabreeze. 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 continues to reflect this scenario. Then, ridging may try to build back 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.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Pred VFR conditions remain in place across all of ENC this evening as the area remains under the influence of a ridge of high pressure centered in the Atlantic. However, our attention once again turns to later tonight as we are forecast to have a rinse and repeat of last night, with patchy fog/low stratus likely developing after midnight.

S-SW winds at 5-10 kts with gusts up around 15-20 kts early this evening are forecast to ease and become light late tonight. With clear skies also in place, a good radiational cooling setup brings a fog and low stratus threat. Greatest chance at seeing fog and low stratus looks to be across SW'rn zones and along the Crystal Coast where highest HREF probs for low vis are (around 40-60%). With this in mind, have MVFR vis developing across the OAJ/EWN terminal and adjacent areas around 07-08Z and then going to IFR vis between 08-09Z. Further north have limited vis to just MVFR starting between 08-10Z. A SCT deck of low stratus at 0.3 kft is also noted in all TAFs given potential threat for low stratus. Vis and ceilings quickly lift with VFR conditions then forecast after about 12-13Z.

Another rinse and repeat day on tap for Tue with mostly clear skies outside of diurnal Cu field and breezy S'rly winds with gusts up to 15-20 kts in the afternoon behind the incoming 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. Seas will continue around 2-3ft, potentially up to 4 ft during the afternoon and evening.

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 as well.

MHX WATCHES/WARNINGS/ADVISORIES

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