Marine Weather and Tide Forecast for Deal Island, MD

NEAR TERM /THROUGH TONIGHT/
As of 345 AM EDT Friday...

Key Messages:

- Unsettled weather, with locally heavy rain potential returns this afternoon and evening.

- Flood watch has been issued for most of the area as heavy rain could potentially lead to flash flooding.

Early morning weather analysis shows primarily zonal flow across the area with a weak trough over the southern Mississippi valley. At the surface, a 1022 Bermuda high continues to sit off the east coast. While to the north the cold front that will bring the showers and thunderstorms continues to slowly move across central PA. Already ahead of the cold front a warm and moist airmass is already making a return to much of the area as dewpoints are already back in the upper 60s to lower 70s.
Temperatures as of 245 am are in the upper 60s to the north and lower 70s further south. Skies remain partly cloudy as high level cirrus move through the area. These clouds will not allow temperatures to fall and lows this morning will be in the upper 60s to the north and lower 70s to the south.

For today, the airmass will be noticeably more humid, with dew pts primarily into the lower 70s. Precipitable water values will rise to 1.75" to 2.1". 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 this 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.

High-Res model guidance continues to depict higher PoPs by late afternoon, and lasting through late tonight. The latest 0Z HRRR QPF values show a broad 10-30% chc for 3" in 3 hr across much of central VA stretching to the VA Eastern Shore this aftn into tonight. In addition, recent High-Res model guidance has QPF values ranging between 1 to 2" across much of the northern half of the CWA within the next 24 hrs. There could also be the potential for locally higher amount's with the stronger storms especially in close proximity to the frontal boundary where the ascent is greater. With high enough confidence in the forecast a Flood watch has been issued for the northern half of the CWA where the parameters look to be favorable. While the other half of the area is not in the Flood watch there will be additional showers and thunderstorms that could bring heavy rainfall and cause very localized flooding. In addition to the Flash flooding threat these showers and thunderstorms could potentially bring gusty winds. Latest forecast sounds show effective bulk shear values between 25 to 30 kt. This is relatively weak but just enough to sustain multi-cell storms.
There is also a non-zero chance of a brief tornado threat. This is the some enhanced low level shear along the front. High temperatures have decreased slightly due to the increasing clouds through the day. Highs will be in the upper 80s to around 90. For tonight the showers and thunderstorms should begin to wind down as daytime heating is lost and the front pushes them off shore. The front will continue to move south slightly south then stall over the area. This will allow for Saturday to be very similar to Today weather wise. Lows for tonight will be in the lower 70s.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
As of 345 AM EDT Friday...

Key Messages:

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

- Additional rounds of heavy rain could lead to additional Flash flooding.

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 models show a moist airmass recovering across the area as PW values are between 2 to 2.3". In addition, 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 will most likely be needed/extended depending on what occurs late Fri/Fri night. In addition, some of the local High- Res guidance has shown showers and thunderstorms training over areas that may have been saturated from the day prior. This will assist in potential Flash flooding occurring quickly.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) due to slightly stronger flow aloft, though a lot of uncertainty exists with respect to specifics on the location of the front.

LONG TERM /MONDAY THROUGH THURSDAY/
As of 345 AM EDT Friday...

Key Message:

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

The latest 0z/13 ensemble guidance from both the GFS and EURO ensembles 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. By the middle of this week there is the potential of a ridge building in across the area. This will lead to much warmer temperatures across the area. There is the potential of heat index values nearing 100 degrees. However, confidence is low at this time and model trends will continue to be monitored.

AVIATION /08Z 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 345 AM EDT Friday...

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 between 2 to 3 ft, with 1-2 ft waves in the Bay. Winds this are between 5 to 10 kt. Benign marine conditions are expected to last through today and the weekend with a slight uptick in winds Saturday. However, they will remain below SCA criteria. There is the potential for showers and thunderstorms in the afternoon and evening. Any strong shower and thunderstorm will be handled with a SMW. Waves are not expected to change much through today as waves will be ~1ft across the bay and 2 to 3 ft across the ocean. Rip currents are expected to remain low for today and tomorrow.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...Flood Watch from 2 PM EDT this afternoon through late tonight for VAZ048-060>062-064-068-069-075>078-082>086-090-099- 100-509>525.
MARINE...None.