Marine Weather and Tide Forecast for Chesapeake, VA

NEAR TERM /THROUGH TODAY/
As of 934 PM EDT Thursday...

Key Messages:

- Mainly dry through early Friday

- Unsettled weather, with locally heavy rain potential returns Friday afternoon.

The latest WX analysis indicates a broad area of high pressure at the sfc and aloft centered from Bermuda to the SE US coast, with a deep upper low over the Plains. The frontal boundary from yesterday has washed out, leaving partly to mostly sunny skies over the region. For tonight,showers and thunderstorm chances quickly diminish as day time heating is lost. Dew points as typical rise after sunset with the loss of mixing, followed by a gradual increase into Friday morning as a light SSW flow prevails and large scale moisture increases on the back-side of the Bermuda High. Not anticipating the widespread fog that we had earlier this morning overnight, though some patchy fog can't be ruled out. Lows will be warmer with the southerly flow and increasing moisture, along with some high clouds, ranging from the upper 60s to lower 70s.

On Friday, the airmass will be noticeably more humid, with dew pts primarily into the lower 70s. Precipitable water values will rise to 1.75" to 2.00" (quite a change from today's values that are <1.00" except in the south). The upper low is forecast to tracking slowly east through MO/AR Fri aftn, with another upper trough across eastern Canada and New England, leading to a tightening westerly flow over the mid-Atlantic. A frontal boundary is expected to be nearly stationary over the northern mid-Atlantic region, potentially brushing our far northern counties Fri evening. This will likely act as a trigger for convection in the aftn/evening in tandem with the increasingly moist humid airmass. It will probably be mainly dry in the morning, with some localized seabreeze development by late morning/early aftn, and other storm development across the mountains. Tough call as to exact precip placement, but most of the CAMs suggest likely PoPs by late aftn, lasting through the evening (potentially longer depending on the front placement).
Still a bit too early for a Flood Watch, but will not that the deterministic QPF forecast has increased significantly, and the 12Z HRRR 3 hr PMM QPF values show a broad 10-30% chc for 3" in 3 hr across much of VA Fri aftn/Fri night. Have this mentioned in the HWO for now. With increased cloud cover, highs will be slightly cooler, in the mid 80s to around 90F, but heat indices will be into the mid 90s given the higher dew pts. As for severe WX, no outlook is in effect given uncertainty in cloud cover and precip timing/initiation. There will be some enhanced low level shear along the front, so a non-zero TOR threat will exist Friday evening, along with at least an isolated wind threat.

SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/
As of 410 PM EDT Thursday...

Key Messages:

- Continued unsettled over the weekend, with additional heavy rain possible.

The front is expected to linger in the vicinity of the region through the weekend, potentially dropping south into the souther portions of the FA late Saturday night and into Sunday.
While this scenario remains uncertain, expect above normal PoPs throughout the area, with the heaviest rain focused over the northern and central zones Sat/Sat night, then probably more across southern VA and NE NC on Sunday. Current deterministic QPF values are 2-4" for much of the region through Sunday evening, though with the scattered tstms, locally higher amounts are likely. A Flood Watch may be needed/extended depending on what occurs late Fri/Fri night. Highs remain warm Sat, in the mid to upper 80s, then trend cooler (at least for the NE 1/2 of the area Sunday with the front potentially to the south). Highs Sunday are forecast in the mid/upper 80s SW to the mid 70s eastern shore. A Marginal SVR risk will be possible (mainly for wind), though a lot of uncertainty exists with respect to specifics on the location of the front.

LONG TERM /MONDAY THROUGH THURSDAY/
As of 420 PM EDT Thursday...

Key Message:

- Daily shower and storm chances continue through the early- middle of next week.

The latest ensemble guidance from both the GEFS and EPS are in decent agreement through the long term. Conditions continue to look unsettled to start the period, through Monday, as an upper level trough passes through the region. Will have likely PoPs again Monday, with highs near normal upper 70s/lower 80s NE and into the upper 80s S. A bit more uncertain heading into the middle of next week, as the upper level ridge off the SE coast expands back north into the local area, with some upper troughing lingering well off to our W and NW. For now, following NBM yields a near climo pattern for chc PoPs, with temperatures trending back above normal, into the low to perhaps mid 90s by Wed-Thu. Overnight lows remain in the 60s to low 70s through the period.

AVIATION /06Z FRIDAY THROUGH TUESDAY/
As of 130 AM EDT Friday...

VFR conditions are expected to prevail through the 6z TAF period. Winds this morning remain light and variable across the inland TAF sites. Winds across the coastal sites remain out of the SSE between 5 to 10 kt. Skies remain partly cloudy with some high end cirrus moving across the area. Later this morning and early afternoon latest model guidance shows showers forming across all taf sites. Timing of these showers is unclear and a TEMPO group has been added for all sites. By the afternoon the showers will begin to strengthen into thunderstorms and prob30s have been added. After sunset tonight the thunderstorm chances dwindle. However, rain showers will prevail late this afternoon. These showers and thunderstorms will bring MVFR flight restrictions to all terminals.

Outlook: Scattered to numerous, mainly aftn/evening showers/tstms return again Sat-Sun, bringing localized flight restrictions in heavy rain and gusty winds. Rain chances remain elevated above climo Monday, before dropping off by Tuesday.

MARINE
As of 450 PM EDT Thursday...

Key Message:

- Relatively benign across the marine area into next week outside of convection.

A weak pressure pattern with a large Bermuda high in place has led to E-SE winds across southern areas, and more of a SSW flow along the Atlantic coast of the eastern shore, Seas are ~2 ft, with 1-2 ft waves in the Bay and generally 1 ft or less in the sound and rivers. A little uptick in winds is expected this evening, but winds will still only be 10-15kt with a few gusts to near 20 kt at most. Similar setup Fri-Sat, though an increase in convective coverage will lead to locally high winds in tstms.
By late sat, a frontal boundary is expected to drop south into the northern waters, which would shift winds to the NE. Still does not look like SCA conditions, with a fairly weak gradient and little to no cold air in the wake of the front.
Nevertheless, would not be surprised to see a brief surge of winds over the northern Bay and northern coastal waters at some point Sat night/Sunday. Forecast shows seas building to ~ 3ft late in the weekend, with a continued 1-2 ft in the Bay.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...None.