Marine Weather and Tide Forecast for Mason Neck, VA

KEY MESSAGES
- 1) Gradually warming temperatures today and Sunday with increasing precipitation chances each day.

- 2) Returning to a summer-like pattern next week.

DISCUSSION

KEY MESSAGE 1...Gradually warming temperatures today and Sunday with increasing precipitation chances each day.

Surface high pressure shifts northeast towards New England today and tomorrow, with gradually warming temperatures expected. High temperatures will be in the 70s to mid 80s across the forecast area. Aloft, multiple shortwave troughs track across the mid-atlantic, bringing daily precipitation chances mainly along and west of the Blue Ridge. Precipitation chances increase Sunday, although coverage of showers and thunderstorms remains scattered due to weak forcing.

KEY MESSAGE 2...Returning to a summer-like pattern next week.

Beginning of next week, ensemble model guidance supports an UL trough continuing to dig in to our region, leading to falling heights and increasing chances for showers and t-storms Tuesday through Wednesday morning. With Tuesday's dew points in the mid 70s to upper 60s and high temperatures in the mid 70s west of the Blue Ridge and high 80s east of the Blue Ridge, there is potential for ample moisture and heat to support showers and t-storm development. This coincides with ample instability rising into the 1,500 to 2,500 J/kg range. With enough vertical shear and height falls, global models support an active day of thunderstorm activity. Ensembles show some sagging of the surface isobaric pattern with its position indicative of a lee- side trough. This will likely be one focus for convection along with terrain circulations and the upstream cold front.

Damaging wind gusts and torrential downpours are possible with any such storm. Given the later arrival of the front, the threat for storms may persist beyond the core diurnal heating hours.

Models show this frontal zone sagging southward to near the Virginia- North Carolina border by mid-week. A shift to post-frontal northwesterlies should gradually quell the threat for thunderstorms.
Dew points begin to fall with temperatures remaining seasonable.
Tuesday's hot temperatures seem to persist into Wednesday through Friday, with high temperatures largely topping out in the upper 80s to low 90s which is close to climatology for late July. Slightly lowered dew points allows for Overnight lows fall into the 60s most nights. This subtle decrease in humid conditions aids lowering precipitation chances to around 20% that could persist through the rest of the week.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
Primarily VFR conditions are expected today with light winds out of the east/southeast. Light rain showers continue across the southeastern portions of the forecast area through early this morning, mainly impacting KDCA. Showers are possible on Sunday along the Blue Ridge with the chance for thunderstorms returning Monday. Sub-VFR conditions are possible in precipitation.
Easterly winds today and tomorrow shift to southerly on Monday.

Tuesday is looking like a much more active weather day ahead of a notable cold front. Convective-related restrictions become increasingly likely, particularly during the afternoon/evening hours. Some showers may linger into Wednesday which could be accompanied by low ceilings. Gradual improvements take place thereafter as winds shift to northwesterly. Before this wind shift occurs, expect mainly south to southwesterly winds with afternoon gusts to around 15 to 20 knots.

MARINE
Light winds are expected today and Sunday with winds remaining out of the east. No hazardous marine conditions are expected.

Southerly winds pick up in intensity on Monday evening/night into Tuesday. Channeling effects could bring gusts to around 20 knots or so, which would be supportive of Small Craft Advisories, particularly across wider waters of the Chesapeake Bay. A convective threat increases through the day on Tuesday which would support the need of some Special Marine Warnings. Winds shift to northwesterly by Wednesday with gusts to around 10 to 15 knots.

TIDES/COASTAL FLOODING
Tidal anomalies rebound within onshore flow today and Sunday, with more sensitive locations potentially reaching Action Stage through the weekend. Annapolis could approach minor flood thresholds early next week.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.