Marine Weather and Tide Forecast for Mount Vernon, VA

KEY MESSAGES
- Daily precipitation chances tonight and tomorrow with a strong cold front yielding a chance at severe weather on Tuesday.

- Drier conditions return mid to late week.

DISCUSSION

KEY MESSAGE 1...Daily precipitation chances tonight and tomorrow with a strong cold front yielding a chance at severe weather on Tuesday.

KEY MESSAGE 1 DESCRIPTION...

NUCAPS soundings from 1540Z and 1724Z showed that earlier inversion seen above 500 mb has eroded, but CAPE remains skinny with MUCAPE in the 300-500 J/kg range from roughly Hagerstown southeast to Fredericksburg. A shortwave-trough dropping into the area in NW flow later this evening is expected to aid in convective development with HRRR ensembles showing the best chance of convection between 23Z and 03Z. Given the skinny/weak CAPE seen on the NUCAPS data, severe thunderstorms appear unlikely this evening.

Warmer and slightly more unstable conditions ared expected Monday, but shortwave ridging aloft may limit thunderstorm coverage.
Overall, it looks like less coverage Monday afternoon than today.

A deepening shortwave-trough will drop from the eastern Great Lks into our area Tue afternoon pushing a strong cold front through the area Tue evening. Strong height falls coupled with strengthening winds aloft will lead to greater thunderstorm coverage and storm organization with a much greater risk of severe thunderstorms. Damaging wind gusts appear to be primary risk due to expected fast storm motions, but isolated tornadoes can't never be ruled out in NW flow. Convection should start exiting the area quickly after 00Z Wed. One caveat is potential for showers and thunderstorms early Tue morning which may leave behind plenty of clouds and limit instability through the day Tue.

KEY MESSAGE 2...Drier conditions return mid to late week.

KEY MESSAGE 2 DESCRIPTION...

In the wake of Tuesday's frontal boundary, the associated low will slowly meander towards the northeast over the next couple of days.
This should reduce rain chances overall, but spotty showers and thunderstorms remain possible as this low slowly slides offshore of New England late in the week. High pressure moves in overhead towards the end of the week bringing drier air and similar conditions overall as the week prior, with highs in the low to mid 80s.

Heading into next weekend, a broad area of low pressure begins to form over the Midwest and track eastward. As temperatures gradually rise towards more normal July averages, this could bring additional shower and thunderstorm chances to the region.

AVIATION /18Z SUNDAY THROUGH FRIDAY/
Scattered thunderstorms are expected this evening, mainly between 23Z and 03Z. Less coverage is expected Monday. Severe thunderstorms are likely Tue afternoon with damaging wind gusts and temporary flight restrictions.

Prevailing VFR conditions are anticipated the second half of the week. Northwest winds could produce gusts up to 25 kts on Wednesday before diminishing some overnight.

MARINE

Fair weather today under light winds. Isolated thunderstorms are possible Monday and numerous to widespread thunderstorms Tue afternoon which may require SMWs. SCA conditions are likely Monday afternoon through the middle of the week.

SCA conditions could persist through Thursday afternoon before winds diminish overall. Southwest winds shift northwest on Wednesday.

TIDES/COASTAL FLOODING
Coastal FLood Advisory has been issued for Anne Arundel County for the early Monday morning high tide. Strengthening southerly flow combined with a near Full Moon will lead to minor coastal flooding around the time of high tides the next several mornings.

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