Marine Weather and Tide Forecast for Harborton, VA

KEY MESSAGES
1) A backdoor cold front will continue to advance southwest this evening into tonight. Widespread fog (potentially dense) is expected to develop tonight into Saturday morning.

2) Warmer for the entire area Saturday as the front lifts back north. Showers and potentially a thunderstorm are also in the forecast later Saturday into Sunday as a cold front approaches from the west and the crosses through the region.

3) A significant warmup will continue through the middle of next week before a stronger cold front crosses the area later Wednesday into Thursday.

DISCUSSION
As of 630 PM EST Friday...

KEY MESSAGE 1...A backdoor cold front will continue to advance southwest this evening into tonight. Widespread fog (potentially dense) is expected to develop tonight into Saturday morning.

This evening, a backdoor cold front has moved through most of the area with a rapid temperature drop. The front has moved through all but Mecklenburg, Lunenburg, and Prince Edward counties, which are still seeing temperatures in the mid 70s.
While behind the front, temperatures have dropped to the 50s inland and 40s near the coast. Still cannot rule out a stray shower along or just north of the boundary this evening into tonight, but overall chances are low (20-30% PoPs).

Widespread fog has begun to develop this evening initially along the coast and will spread inland later tonight into early Saturday morning. Fog may become dense, especially closer to the coast, where HRRR probs show ~40-60% chances for visbilities below a quarter of a mile. Temperatures drop into the 40s for the northeastern 2/3rds of the forecast area with the far SW remaining in the 50s.

KEY MESSAGE 2...Warmer for the entire area Saturday as the front lifts back north. Showers and potentially a thunderstorm are also in the forecast later Saturday into Sunday as a cold front approaches from the west and the crosses through the region.

The boundary lifts back to the north on Saturday as a cold front begins to approach from the west. At this time it appears most of the area will be in the warm sector Saturday afternoon with highs expected to range from the mid 70s to around 80 inland to the 60s to low 70s closer to the coast. The 12z NAM tries to hang out to the cooler airmass through most of the day, delaying any warmup until the evening. While this solution is an outlier, the potential is nonzero and we will have to monitor observational trends Saturday morning. Isolated to scattered rain showers are also possible Saturday afternoon and Saturday night, especially across northern and western portions of the forecast area.

Rain chances increase on Sunday as the front pushes into the area before likely stalling and dissipating. The highest rain chances Sunday will be focused across the southern half of the area. Thunderstorms will also be possible, while widespread severe weather is still not expected, machine learning/AI models are pinpointing at least the potential for a low-end severe weather threat mainly across far southern VA into NC. From looking at model soundings, the main threat would be for a damaging wind gust with any stronger storms. SPC also just highlighted the southern half of the area with a Day 3 Marginal risk with the afternoon update. Temperatures remain above average on Sunday with high temperatures in the mid to upper 70s (60s to low 70s coast and Eastern Shore). Monday will again be mild with a lingering shower possible for SE VA and NE NC along the remnant frontal feature.

KEY MESSAGE 3...A significant warmup will continue through the middle of next week before a stronger cold front crosses the area later Wednesday into Thursday.

Well above average temperatures continue into next week, likely peaking on Tuesday and Wednesday with widespread (inland) high temperatures in the low 80s possible. Based on the current forecast, record high temperatures will be in reach at RIC and potentially ORF with both sites having current record highs in the low 80s on both Tuesday and Wednesday. A stronger front likely approaches later Wednesday into Thursday bringing the next chance for widespread rain (and potentially thunderstorms).
There could be a severe weather potential with the front Wednesday into Thursday, but the timing of the frontal passage (overnight Wednesday or early Thursday) may help to keep the threat limited. Temperatures return to closer to normal or below normal later in the week..

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
As of 1230 AM EST Saturday...

A backdoor cold front is SW of all terminals this morning, with widespread IFR-LIFR CIGs and VSBY N of the boundary. Winds are 5-10 kt out of the E-NE. Fog, potentially dense, and LIFR/VLIFR CIGs are expected through at least 14z. The front will gradually lift back N after sunrise and conditions gradually improve through the morning. However, this could be a slow process and have maintained low stratus through the early aftn for all terminals, before improvement to VFR thereafter. SBY likely remains IFR all day though could briefly scatter out there around 21z. The front should be N of the area by this evening and tonight with SW winds increasing to ~10 kt. SW LLWS is possible after 00z at RIC and SBY.

Outlook: Isolated showers are possible late tonight into Sunday morning, with more widespread showers (and potential thunderstorms) possible Sunday. Mainly VFR Monday through much of Wednesday. A stronger front approaches later Wednesday.

MARINE
As of 230 PM EST Friday...

Key Messages:

- Marine fog remains a concern for northern coastal waters through at least this evening.

- A sub-SCA wind and sea state is expected through Saturday.
The next potential for SCAs is Saturday night into Sunday

The backdoor front that has been pestering the local area this week sagged to the south today, placing all of the local waters north of the front and in NE flow. Latest obs show 5-10kt for most places, but have seen a few obs closer to 15kt in the lower James. Seas are around 3ft. Marine fog is still a problem and has spread south and into the bay, prompting an expansion of the Marine Dense Fog Advys. Fog will likely remain in place through at least this evening, so went ahead and extended the Dense Fog Advy through 7pm with additional extensions possible. The front gradually slides back north late tonight, shifting the winds back to the south and hopefully clearing out the fog by mid morning tomorrow. S-SW winds then increase tomorrow afternoon and evening to 15-20 kt early Sunday morning. SCAs appear probable for the coastal waters Sat night as sustained winds increase to around 20 kt with ~5 ft seas (especially N), with SCAs also possible on the Chesapeake Bay and rivers due to 20-25 kt gusts. Lighter winds return Sunday-Monday.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Dense Fog Advisory until 10 AM EST this morning for ANZ630>638- 650-652-654-656-658.